WHEAT PERFORMANCE TEST DATA

It is time to start purchasing your wheat seed to plant this fall.  To help you make those decisions, the 2018 Ohio Wheat Performance Test data is now available.

There were five test locations around the state, Darke, Marion, Pickaway, Wood, and Wayne Counties.  Wheat was seeded within two weeks of the fly free date at Pickaway, Wood, and Wayne Counties.  Darke and Marion County sites were planted 21 to 19 days after the fly free date.  Wheat entered dormancy in good shape at all locations. 

The two sites closest to us and most similar in soil type are Darke and Marion Counties.  The Darke County site has a Crosby soil type and Marion County has a Glynwood soil type.

The highest yielding variety for 2018 at Darke County was Ebberts 916 at 90.7 bushels per acre. The following varieties were statistically similar to Ebberts: Steyer Shiloh; Rupp RS918; and Shur Grow SG-1546S.  When deciding what varieties to plant it is a good idea to look at data for multiple years to see how consistent a variety can be.  The highest yielding variety from 2016 to 2018 was AGI 217B at 101 bushels per acres and a test weight of 57.0 pound per bushel.  Other varieties within four bushels of the highest yielding variety in order are Dyna-Gro 9692, AgriPro SY 100, Wellman W204, and Shur Grow SG-1546S.  Test weight for these varieties ranged from 54.9 to 57.0 pounds per bushel.

 The highest yielding variety for 2018 at Marion County was Shur Grow SG-1552 at 90.7 bushels per acre.  There were 36 varieties statistically similar to the Shur Grow variety, but the top four of these 36 varieties were Wellman 312, AGI 217B, Ebberts 916, and Seed Consultants SC 13S26.  The highest yielding variety at Marion for 2016 to 2018 was AgriPro SY100 at 109 bushels per acre and a test weight of 57.0 pounds per bushel.  Other varieties within four bushels per acre were AgriPro SY547, Yerks Y2313, Shur Grow SG-1552, Wellman W304, and AgriMAXX 454.  The test weight for these varieties ranged from 56.0 to 57.5 pounds per bushel.

Yield is a very big component in choosing a variety, but disease resistance is also important.  Resistance to Fusarium Head blight is probably the most important trait to have, but resistance to powdery mildew, glume blotch and leaf blotch are important as well.  AGI Bolt, AgriMAXX 463, Albert Lea LCS3204, Ebberts 990, Prible PA218, Shur Grow SG-1537S, Wellman 304, and Dyna-Gro WX17775 are resistant to Fusarium head blight.  Rupp RS910, Certified Starburst, Certified Sunburst, Albert Lea LCS 3204, Certified Freedom, and Certified Hopewell are moderately resistant to powdery mildew.  Nineteen varieties have resistance to glume blotch.  Seventeen varieties have resistance to leaf blotch.

For further information about the 2018 Wheat Performance Test visit the following website:  https://www.oardc.ohio-state.edu/wheattrials

JAPANESE BEETLES

Last week the Japanese beetle began emerging.  They are all over the place feeding upon greater than 350 known plant species.

The scientific name for the Japanese beetle is Popillia japonica.  The Japanese beetle was accidentally introduced into the United States on horticultural nursery stock in 1916 in New Jersey.  It is present in every state east of the Mississippi River, except Florida, but can also be found west of the Mississippi river.

The Japanese beetle adult is quite large measuring 1/2 of an inch.  The fore wings or the hard wing coverings are bronze to coppery-brown in color.  The head and the thorax, the middle part of the insect are a metallic green color.  Another identifying feature are the six tufts of hair on each side of the abdomen, the area below the wing coverings.

The larval, worm or grub, stage of the Japanese beetle feeds in the soil on the roots of grasses and ornamentals.  When the population is great enough it can kill the grasses.  This usually only occurs in home lawns.  In soybean the adult beetles usually only feed on the upper leaves of the plant.  They eat the soft tissues between the veins leaving a lace-like skeleton pattern.  They do not eat on the pods, because the pods are not large enough at this time.  In corn it is possible to eat the leaves as well, but this is uncommon or when the population is large/dense.  In corn the Japanese beetles are attracted to the silks.  When multiple beetles congregate they will eat all of the silks from an ear of corn.

The Japanese beetle only has one generation per year.  Japanese beetle adults emerge from the soil in late – June and will continue to emerge for a few weeks.  The adults are most active in the afternoon in full-sun. Immediately after emergence they begin to mate and the females will go to grassy areas to lay the eggs.  The female burrows two to four inches deep in the soil to lay the eggs.  The eggs hatch in about two weeks.  The eggs and young larvae need sufficient moisture to grow, so a long dry spell in mid-July can drastically reduce the population!  The grubs grow quickly feeding on the roots of grasses and ornamentals.  By the time the larvae reach full size (one to one and 1/4 inch) the larvae have moved to within one to two inches from the soil surface.   However if soil conditions become dry the larvae will move deeper into the soil.  After a few frosts the larvae start to move to a four to six inch soil depth to survive for the winter.  Some grubs have been found 20 inches deep in the soil.  The grubs become inactive when the soil temperature reaches 50 degrees F.  The grubs become active again in the spring when the soil temperature has reached 50 degrees F and move back to the surface.  The larvae will feed for another three to five weeks, then will begin to pupate, resting stage, to prepare for emergence as an adult again in late-June.

The threshold for corn is when three or more beetles are present per ear, silks have been clipped to ½-inch and pollination is less than 50 percent.  The threshold for soybean is when 20% of a leaf has been defoliated during the reproductive stage.  To scout walk over a large area of the field pulling three leaves off of a plant, one from the lower canopy, one from the middle canopy and one from the upper canopy.  Collect leaves from ten plants and evaluate the amount of defoliation.  When scouting do not just check the field perimeter because the greatest number of beetles are usually present along the edge of the field.

When spraying it may be possible to only spray the perimeter of the field since that is where the greatest number of beetles are present.  There are many insecticides available to control Japanese beetles in corn.  Some of the products include Baythroid, Sevin, Capture, Asana, Warrior, Hero, and Cobalt, but there are others.  There are more products available in soybean to control Japanese beetle than corn.  All of the products mentioned above, except Capture can be applied to soybean.

ZERO TOLERANCE

As I drive around the county, I am starting to see some weeds coming up over the top of the soybean canopy.   Giant ragweed and waterhemp are the most common I am seeing.  These weeds are appearing due to resistance to glyphosate and likely even PPO inhibitors such as Flexstar and emergence after the postemergence application.

Zero tolerance is a philosophy of controlling 100% of the weeds in a field when only using herbicides to control weeds.  The goal is to maintain fields with no weeds because if a plant is present after a herbicide application it is likely resistant to the herbicide.  Zero tolerance must be the goal, so if we do not control every single weed in a field at least we can get very close.

What strategies need to be employed to achieve 100% weed control?  The first step is to know the weed pressure in a particular field, then devise the best preemergence followed by postemergence weed control program for the field.  The next step is to scout the field before any herbicide application to identify all weed species present in the field and determine the proper herbicide mixture or if an alternative spray program is required.  Next at 5 to 10 days after the herbicide application scout the field to determine the effectiveness of the herbicide application.  This time period is extremely important in order to have time to respond to any surviving weeds with a second application before the weeds get too large for an alternative herbicide.  If a contact herbicide was applied scout closer to the 5 day period, but if a systemic herbicide was applied scout closer to the 10 day period.

If there are many weeds surviving the first application make a second postemergence application with an effective alternative herbicide.  If weeds start to appear over the soybean canopy after all herbicide applications have been made, then the next option is to remove the weeds by hand.  I know the last thing anyone wants to do is to remove weeds by hand from a field, but if this is not done then you are allowing the surviving or resistant plants to add seeds to the seed bank and become more prevalent making weed control more problematic.  Weed seeds can remain viable in the soil for greater than two years and in some cases hundreds of years.  Most weed seeds survive greater than four years in the soil.

As an example, if one waterhemp plant is left in a field producing just 100,000 seeds, which is a low number considering waterhemp can produce over 500,000 seeds per plant, and just 10 percent of these seeds emerge the next season, then there will be 10,000 plants in that area next season.  There will be new plants in other areas of the field as well as the seeds will be spread by the combine.  If only 50% of these plants are resistant to glyphosate, then 5,000 plants will survive.  If 5,000 plants produce 100,000 seeds per plant you end up with 500,000,000 seeds at the end of the second season.  If only 10% of those seeds germinate the next season, then 50,000,000 plants will be present that are resistant to glyphosate.  If only 50% survive, that leaves 25,000,000 plants producing 100,000 seeds per plant producing a total of 2,500,000,000,000 seeds after the third season.  That is alot of seeds to deal with in the fourth season.

In Arkansas they hand weeded, I believe, a 40 acre field of palmer amaranth taking about 100 hours to remove all plants.  The next season they applied the same herbicide program and it only took around 10 hours to remove the plants by hand.  This shows the importance of removing plants by hand.  If you hand weed when just a few plants are present, it will not take long and you can keep the number of resistant weeds to a very low level.  Weeds that survive a herbicide application are a future problem.

For those fields not yet sprayed remember this discussion and scout accordingly, making sure weeds do not get large after the application.

WHY SCOUT AFTER
HERBICIDE APPLICATIONS?

Postemergence herbicide applications have been made in the last two to three weeks in some corn and the last week in soybean.  Scouting before making a postemergence herbicide application is critical to successfully controlling the weeds in a field.  Scouting that same field after the herbicide application is just as important.  Scouting is necessary to determine whether all weeds were controlled and to determine the cause if not controlled.

If contact herbicides were applied, scout fields 5 to 10 days after application.  If translocating herbicides were applied scout fields 7 to 14 days after application.  Scouting on the early side of each range is preferable to learn the most about the effectiveness of the herbicides, but weeds may not be dead at this time and require a second scouting.  If the weather is cold and cloudy it usually takes longer to determine if the weeds will die.  Timely scouting is most important for soybeans because there are few options to controlling surviving weeds since contact herbicides will likely need to be applied.

The number one reason to scouting timely after a postemergence herbicide application is to respond quickly in case a second application is necessary.  Waiting to scout too long after the initial application, especially when needing a contact herbicide, will allow the weeds to recover too much making it difficult for the second herbicide application to be effective.

If more than a single weed species is present after a herbicide application and the injury symptoms are somewhat uniform, then an incorrect rate, poor application, or poor weather conditions likely caused the herbicide to be less effective.  In this situation, ideally choose a herbicide having a different site of action that will effectively manage the weed, although applying the same herbicide may be effective in the second application

If marestail, waterhemp, giant or common ragweed are present after the postemergence application of glyphosate (Group 9), ALS-inhibitors (Group 2), and/or PPO-inhibitors (Group 14), suspect herbicide resistance.  If plants of these species are dead while other plants appear normal and all other plants respond somewhere between dead and near normal, then you can almost guarantee resistant biotypes are present in the field.  In this situation herbicide(s) having an alternative site of action will need to be applied from 14 to 21 days after the initial application.  Contact herbicides should be applied at the 14 day interval.

Timely scouting after a postemergence herbicide application is critical to responding quickly with an effective second strategy.

WHEN SHOULD POSTEMERGENCE
HERBICIDES BE APPLIED TO CORN?

In my weekly drive around the county, most corn fields are relatively clean, but there are some early planted fields with no residual herbicides applied that need to be sprayed right away.  There are weeds breaking through the residual herbicides.  This is a banner year for yellow nutsedge.  Other weeds coming through the preemergence herbicides include annual grasses, giant ragweed and velvetleaf.

Corn does not compete well against weeds, especially grassy weeds.  Corn yield is almost never reduced when weeds are controlled at the one to two inch stage.  However as weed size becomes larger than two inches, crop yield usually begins to decline.  The amount of yield loss will depend upon weed height and density and water and nutrient availability.  The larger the weed beyond two inches the more likely yield loss will occur.  The greater the weed density the greater the chance for yield reductions due to weeds.  The drier the soil conditions the greater the yield loss from weeds.  The lower the fertility levels the greater the loss of corn yield.  Therefore the denser and taller the weeds and the dryer the soil and the lower the fertility the greater the corn yield loss.  With this combination of characteristics, yield loss could begin when weeds are between one to two inches in height.

Another aspect to consider is the loss of nutrients by letting the weeds be present in the corn.  The larger the weeds the more fertilizer is taken up into the weed and likely will no longer be available to the corn plant for the rest of the season.  This loss of nutrients in particular nitrogen, is a loss of revenue.  Side-dressing nitrogen after the herbicide application can usually compensate for the loss of nitrogen.

For no-tillage fields with no burndown a comprehensive herbicide mixture with residual chemistry should be applied as soon as possible.  If corn is Roundup Ready apply the maximum rate of glyphosate at 1.125 pounds acid equivalent per acre (32 fluid ounces of a Roundup product) and include Capreno, Impact, DiFlexx Duo, or Laudis plus atrazine at 2.0 pounds active ingredient per acre.  Other products with longer residual activity would include Resicore, Lexar, Accuron, or SureStart plus Stinger.  Include atrazine with these products to a total of 2.0 pounds active ingredient.  Use the best adjuvant to maximize activity of the products being added to the glyphosate.  These applications need to go on immediately to eliminate competition and to allow for the use of atrazine.  Atrazine can not be applied after 12 inch corn.

For fields that were tilled and no residual herbicides were applied, the same products listed above mixed with glyphosate in Roundup Ready corn will work as well.  The herbicides must be applied before three inch weeds.  This type of comprehensive program is necessary to control glyphosate resistant weeds and provide long-term residual control, especially for waterhemp.  For best residual control of waterhemp include acetochlor, metolachlor, or Zidua, but these herbicides must be applied before 12-inch corn.

For fields where residual herbicides were applied, wait until weeds reach three to four inches in height and apply glyphosate at the full labeled rate of 1.125 pounds acid equivalent per acre.  If glyphosate resistant weeds or waterhemp are present, then other herbicides need to be included.  If corn is 12 inches or less add atrazine to reach the maximum rate of 2.5 pounds active ingredient per acre for the season.  Including atrazine will provide residual control of weeds depending upon the rate being used.  Include Callisto, Capreno, DiFlexx Duo, Hornet, Impact, Laudis, Realm Q, or Status with the atrazine and glyphosate to improve control of glyphosate-resistant weeds and provide additional mechanisms of action.  If corn is taller than 12 inches, DiFlexx Duo provides the most effective and broad-spectrum control of weeds.  The next most effective herbicides to mix with glyphosate on large corn include Capreno, Laudis, or Status.  Apply the maximum rate of these postemergence herbicides.  Use the best adjuvant for the herbicides being mixed with glyphosate to maximize activity.

Glyphosate is somewhat effective on yellow nutsedge.  It is most effective when plants are beginning to flower, but you can’t wait that long in corn or make two applications.  The most effective herbicide to control yellow nutsedge is halosulfuron (Permit) applied at 1 ounce per acre.

Consult the Ohio, Indiana, and Illinois Weed Control Guide for rainfastness and the use of these herbicides where a soil-applied organophosphate insecticide was used.

WHAT IS THAT YELLOW
FLOWERING WEED?

A weed by the name of cressleaf groundsel, also known as butterweed or yellowtop, is showing up all over the county in home landscapes, road ditches, unplanted fields, wheat, hay, and pasture fields.  The scientific name is Packera glabella (formerly Senecio glabellus).

The plant is in the Aster family so the flower looks like a small sunflower head having yellow outside petals and yellow disk (head) flowers.  The flowers are produced at the ends of many branches coming from the terminal part of the plant and from nodal shoots.  The plant begins as a rosette with initial leaves being rounded and no lobes.  After about the fourth or fifth leaf opposite lobes appear on the leaf with one rounded lobe at the top.  The leaves may have a purplish color in the fall.  When the stem develops it is reddish to purplish in color, especially at the base and the stem is hollow and ridged.

Cressleaf groundsel has a winter annual life cycle.  That means the plant emerged starting in August and continued to emerge throughout the fall.  It survived the winter in the rosette stage and resumed growth this spring.

The biggest reason that this weed can be found all across the county is that the seeds leave the plant and are picked up by wind currents and deposited anywhere down wind for a distance of one to two miles.

The two biggest problems right now are the plants that will be releasing seed very soon for this fall’s germination and the plants in wheat, hay, and pasture fields.  The concern for the plants in the wheat, hay, and pasture fields is that the plant is poisonous to cattle, horses, goats, sheep, and humans.  The toxin is still present in dried hay.  The plant is fairly toxic causing weight loss, unthriftiness, poor hair coat, anorexia, behavioral changes, sunscald, aimless walking, diarrhea, jaundice, liver damage, and possibly death.  All parts of the plant are poisonous.  I have seen some fields that should not be harvested for hay or straw.  There are some questions that are unanswered such as will the animal pick out the plants and not eat them and how many plants do they need to consume to become sick.  Chopping the hay for silage is the worst option because the animal will eat the plants since it is mixed in as small pieces.

At this time nothing can be done to eliminate these plants other than hand weeding or mowing around patches and coming back and mowing the weedy areas and chopping it back on the ground.  Just mowing the weedy areas without chopping may allow the plants to be picked up when raking the second cutting.  The time to cut hay fields is when the seeds of the earliest plant has started to blow away.  That way the plants are more likely to die and not regrow because some seeds have hit maturity.  If they do not regrow then they will not be a problem in the second cutting. 

For future reference apply herbicides in the fall in no-tillage, hay, and pasture fields.  Herbicides can be applied in the spring on wheat, but must be done early when plants are small.  Huskie and 2,4-D will effectively control cressleaf groundsel.  For alfalfa apply Velpar or metribuzin after dormancy in the fall.  In no-tillage fields a simple application of 2,4-D ester and glyphosate in the fall will control cressleaf groundsel.

SCOUT ALFALFA FIELDS
FOR ALFALFA WEEVIL

After larvae hatch, they move to the growing point to begin feeding.  There are four instar stages of alfalfa weevil.  The 1st and 2nd instar stages are difficult to see as larvae are small, yellowish green and have black heads.  The 3rd  and 4th instar stages are easily identified by their green color, a white stripe over the top of the larvae, and a black head.  The 3rd  and 4th instar stages cause the greatest damage.

To scout for alfalfa weevil, randomly cut ten alfalfa stems at the crown and place them upside down in a bucket.  Once collected, vigorously shake the plants in the bucket to dislodge the larvae and count the number of larvae.  Check a few of the growing points for instar stages 1 and 2 because they are not easily dislodged.  After determining the number of larvae measure the length of at least 5 stems.  Repeat this process two more times to collect a total of 30 stems.  The economic threshold is based upon the number of larvae per stem, the height of the alfalfa, and the size of the larvae.  If one or more large (instar 3 or 4) larvae are detected with stem length of less than 12 inches, a rescue treatment is recommended.  If alfalfa is between 12 and 16 inches and 2 to 4 larvae are collected per stem, especially if alfalfa is under stress, treatment is recommended.  When alfalfa is greater than 16 inches tall with more than 4 larvae per stem, early cutting is recommended.  After harvesting alfalfa early in a field scout these fields for larvae on regrowth of plants.

There are 37 insecticide choices to control alfalfa weevil.  Go to the following website to observe the list:  https://agcrops.osu.edu/sites/agcrops/files/publication-files/545%281%29... .  Pre-harvest intervals range from 0 to 21 days, so choose products based upon when harvest is expected.  Alfalfa harvest will likely begin in 10 to 14 days. 

PREPARING FOR BURNDOWN
HERBICIDE APPLICATIONS

Despite the wet and cold weather right now it will dry out and warm up at some point and we will begin the planting process. For those individuals planting crops without tillage (no-tillage), weeds need to be controlled prior to planting (burndown application). In corn it is best to control common chickweed at least 10 days before planting because cutworm moths are attracted to the common chickweed and will feed on the corn as it emerges if the chickweed is still green.

A combination of glyphosate and 2,4-D ester is most commonly used to control weeds prior to planting corn and soybean. Apply glyphosate at 1.125 pounds acid equivalent per acre or 32 fluid ounces per acre of a Roundup branded product plus 2,4-D ester at 0.5 pound acid equivalent per acre or 1 pint per acre of a 4.0 pound per gallon product. This combination will control most species. Exceptions to this is annual ryegrass, dandelion, and glyphosate-resistant marestail. Soybean planting must be delayed 7 days after the application of 2,4-D ester at 1 pt/A and is a good recommendation for corn as well. It is possible to injure corn when 2,4-D ester is applied close to planting, especially when mixed with an acetochlor product.

The most effective herbicide program to control dandelion in corn is to apply Lumax or Lexar plus 2,4-D ester. Accuron or Instigate plus an atrazine premix should provide very similar control. Expert plus 2,4-D or Balance or Corvus plus atrazine or any other treatment containing glyphosate plus 2,4-D plus atrazine containing product should provide similar control. Use water as the carrier, not liquid nitrogen. The most effective herbicide program to control dandelion in soybean is to apply a chlorimuron containing product or a cloransulam containing product with glyphosate plus 2,4-D ester. Chlorimuron can be a little more effective than cloransulam.

To control annual ryegrass apply glyphosate at 1.5 to 2.0 pounds acid equivalent per acre or 44 to 56 fluid ounces per acre of a Roundup formulation.

Control of glyphosate-resistant marestail requires special attention to detail and following a specific plan. To control marestail following a fall-applied herbicide treatment apply glyphosate at 1.5 pounds acid equivalent per acre or 44 fluid ounces of a Roundup formulation plus 2,4-D ester at 1.0 pound acid equivalent per acre or 2 pint per acre of a 4.0 pound acid equivalent per gallon product. When applying 2,4-D at 1.0 pound per acre, planting must be delayed for 30 days after application, unless using Weedone 650, E-99 or Salvo which is 15 days before planting. Another option would be to apply glyphosate at 1.125 pounds acid equivalent per acre plus 2,4-D ester at 1 pint per acre plus a new herbicide called Elevore at 1 fluid ounce per acre plus a methylated seed oil before corn or soybean. Corn and soybean planting must be delayed 14 days when using Elevore. Other options include Sharpen or Zidua Pro plus a methylated seed oil plus glyphosate or glufosinate (Liberty), glyphosate plus 2,4-D plus Sharpen or Zidua Pro, or 2,4-D ester plus Gramoxone (3 to 4 pints per acre) plus a metribuzin containing product (at 8 ounces per acre total of metribuzin 75 DF).

If a fall-applied herbicide program was not used to control marestail then apply glyphosate plus 2,4-D ester plus Sonic (2.5 ounces per acre) as soon as possible and follow with Sonic (2.5 ounces per acre) plus Gramoxone at planting, apply glyphosate plus 2,4-D ester plus metribuzin (4 ounces per acre) now followed by Canopy (4 ounces per acre) plus metribuzin (2 ounces per acre) plus Sharpen at planting, or apply glyphosate plus 2,4-D plus metribuzin (6 ounces per acre) now followed by Envive (4 ounces per acre) plus 2,4-D ester 7 days before planting.

It is recommended to include flumioxazin (Valor), sulfentrazone (Spartan), or metribuzin with the programs mentioned above to obtain residual control of marestail and other weeds. Soybean planting must be delayed 14 to 30 days if flumioxazin or sulfentrzone is mixed with Sharpen, Zidua Pro or Verdict.

Include residual herbicides with glyphosate plus 2,4-D in corn and soybean even if you do not have dandelion or marestail. If applying a saflufenacil (Sharpen) containing product or Gramoxone add a methylated seed oil. If applying a saflufenacil containing product or Gramoxone apply at a minimum spray volume of 20 gallons per acre. Use nozzles to achieve medium to coarse spray droplets with Gramoxone and saflufenacil. With these small droplets take special precautions to reduce drift.

Have a successful burndown season.

WHEN SHOULD HERBICIDES
BE APPLIED TO WHEAT?

Weeds in winter wheat are usually not as big of a problem as compared to weeds in corn and soybean. The planting of the winter wheat in September and October and the very competitive nature of wheat are two main reasons for fewer weeds, especially summer annual weeds.

However weeds can still be a problem in wheat, especially winter annual weeds such as purple deadnettle, henbit, field pennycress, shepherd’s-purse, common chickweed, cressleaf groundsel, and marestail (horseweed) because they emerge in the fall before and after planting of winter wheat.

The key factors to managing weeds in winter wheat is timing of herbicides and choosing the correct herbicide. There are two important aspects of timing of herbicides, potential of injury to the winter wheat and timing to maximize weed control. Not many herbicides injure winter wheat unless they are mixed with liquid fertilizer as the spray carrier, with the exception of dicamba (Banvel / Clarity and premix Pulsar). Dicamba applied at and after jointing of winter wheat (Feekes stage 6) can drastically reduce winter wheat yield because this is the stage when the head begins to develop. Winter wheat has not jointed yet, but may start jointing later this week or next week. Therefore carefully scout winter wheat fields to determine its development if dicamba is the planned herbicide. Buctril, Starane, Stinger, WideMatch, Quelex, Orion, and Axial have the greatest flexibility of timing as they can be applied up to the last leaf (flag leaf) being visible. All remaining herbicides can be applied between jointing and flag leaf emergence.

The other important aspect of timing is to maximize weed control. Winter annual weeds started growing last month, although slowly, despite the cold temperatures. Therefore it is time to begin applying herbicides to control winter annual weeds. If you expect summer annual weeds such as giant ragweed or common lambsquarters to be a problem now is not the time to apply herbicides as most weeds have not emerged yet. If you want to control winter and summer annual weeds, then an herbicide application between jointing and the second node is usually a good time.

Talinor is a new winter wheat herbicide. Talinor will control winter annual weeds except purple deadnettle and henbit, but will control all summer annual weeds. Quelex is a relatively new winter wheat herbicide. Quelex will control most winter annual species, especially marestail and will control lamsquarters, pigweed, and smartweed. Finesse, Report Extra, Huskie, and tribenuron + thifensulfuron (ex. Harmony Extra) will effectively control more winter annual weeds than Quelex. Huskie, Talinor and Quelex are the only herbicides of those mentioned that will control marestail resistant to ALS-inhibiting herbicides (Group 2). Cleansweep D or M, Curtail, dicamba, Huskie, and Pulsar plus MCPA provide the most effective control of the most common summer annual weeds.

Now that Talinor is labeled for winter wheat, crop rotation must also be considered. Talinor has a 10 to 12 month crop rotation restriction to soybean, a 9 to 12 month to alfalfa, a 18 month to red clover, a 10 month to sorghum, and a 3 month to oats. Quelex has a 15 month crop rotation restriction to red clover, a 9 month to alfalfa, and a 3 month to soybean, sorghum and all types of corn. Curtail has a 18 month crop rotation restriction to red clover and 10.5 months to alfalfa, soybean, popcorn, and sweet corn. Pulsar has a 12 month crop rotation to red clover, a 9 month to alfalfa, soybean, and popcorn, and a 4 month to sorghum and sweet corn. Huskie has a 4 month crop rotation restriction to soybean, corn and alfalfa.

Selection of the right herbicide applied at the right time is extremely important to maximizing weed control, reducing the risk of wheat injury, and rotation to other crops.

WHAT IS A GIANT RAGWEED
AND HOW TO MANAGE IT?

Giant ragweed is one of the worst and most prevalent weeds in farmer’s fields in Auglaize County. Giant ragweed is a broadleaf plant that belongs to the Aster or Asteraceae family. The Aster family has the greatest number of species of any plant family. The scientific name for giant ragweed is Ambrosia trifida. Other common names for giant ragweed include horseweed, tall ragweed, great ragweed, kinghead, blood ragweed, and buffaloweed.

Giant ragweed has a summer annual life cycle meaning it completes it’s life cycle in one year. So it germinates in the spring and begins flowering around August 1st to 15th and dies naturally in the fall or after a hard freeze. Giant ragweed is one of the earliest emerging weeds in the spring. It has already started to emerge in fields this spring!

Giant ragweed is easily identified. At this time of the year it will have thick, fleshy, spoon-shaped cotyledons. The first true leaves are opposite and have no lobes or three small lobes, but will have a serrated margin. The first four to eight nodes of the plant will have opposite leaves, but then will switch to an alternating pattern. The second or third node and all subsequent leaves will usually have three very large deep lobes, but it is possible to have no lobes or five lobes. The leaves can become very large being similar in size to a small or medium-sized hand. There are hairs on the stem of a giant ragweed plant. The stem can reach a diameter of 2 inches.

When it flowers the ending point of the branches are the male flowers, while the female flowers, where you will find the seeds, are in the nodes of the plant below the male flowering stems. This makes giant ragweed a monecious plant meaning the male and female flowers are separated from each other, but on the same plant similar to corn.

Giant ragweed plants commonly reach a height of six to eight feet. However, I have seen plants get over 20 feet tall! This usually happens in a low light intensity area with very thick giant ragweed densities or in a corn field.

Giant ragweed is extremely competitive! If nothing is done and it is dense it will completely eliminate corn and soybean plants. Research has shown that it takes only two giant ragweed plants per square meter to reduce corn yields 37 percent and only one giant ragweed per square meter to reduce soybean yield by 52 percent.

Giant ragweed can become resistant to herbicides, although not very rapidly and shows variable responses, making it difficult to be confident the plants are resistant. We know giant ragweed is resistant to Acetolactate Synthase inhibiting herbicides such as FirstRate and Classic and glyphosate, Roundup, in individual plants or together in the same plant in Auglaize County. We believe that giant ragweed is resistant to Protoporphyrinogen Oxidase (PPO) inhibiting herbicides such as Flexstar and Cobra in Auglaize County. We believe an individual plant can be resistant to all three types of herbicides in the county. When that occurs there are no longer any other postemergence (after a plant emerges) herbicides to effectively control giant ragweed in Roundup Ready soybean. The only way to control these three-way resistant giant ragweed plants in soybean is to plant LibertyLink soybean and apply Liberty or to plant Xtend soybeans and apply dicamba!

To effectively control giant ragweed in soybean apply a combination of preemergence herbicides such as metribuzin (Sencor) and FirstRate or Classic. These are the only preemergence soybean herbicides that may be effective, but metribuzin is marginal and plants are likely resistant to FirstRate and Classic. Follow up with a postemergence herbicide application of glyphosate plus Flexstar in Roundup Ready soybean as there are not too many giant ragweed populations resistant yet to Flexstar. As mentioned above Liberty and dicamba will control giant ragweed as long as you have the appropriate soybean planted.

To effectively control giant ragweed in corn apply a preemergence herbicide containing atrazine at rates up to 1.5 to 2.0 pounds active ingredient, unless the soil is highly erodible. Including mesotrione, Callisto, or Balance Flexx with the atrazine will improve control. There is no preemergence herbicide alone or in combination that will control giant ragweed through the entire season because the preemergence herbicide will dissipate before giant ragweed quits germinating which can be in mid-July. A postemergence herbicide or combination of herbicides will be necessary for complete control of giant ragweed, especially in fields having a history of giant ragweed. Bromoxynil, Callisto, Impact, or Laudis mixed with atrazine, 2,4-D, dicamba, Hornet, Stinger, DiFlexx Duo, DiFlexx, Status, and Liberty in LibertyLink corn can effectively control giant ragweed postemergence.

TERMINATE COVER CROPS EARLY

As I drive around the county I have observed a fair amount of cover crops planted. Cover crops provide protection from soil erosion, utilize nutrients applied in the fall, and improve soil health. However, the termination of cover crops can be difficult if not managed properly.

Improperly terminated cover crops can potentially become weeds, especially annual ryegrass, and can slow soil drying and warming in the spring. When cover crops are allowed to get excessively large the plants can actually dry out the soil and cause yield loss, especially for corn. It is especially important to control cover crops at least 10 days in advance of planting corn to break the green bridge between the cover crop and corn emergence to reduce the risk of cutworm and armyworm problems.

When selecting an herbicide program for termination of a cover crop consider: The cover crop species; The cover crop growth stage; Other weed species present; The crop to be planted; The weather conditions at application; and The type of herbicide used.

Annual ryegrass is the most difficult species to control. Terminate ryegrass before it reaches six inches in height or before the plants begin to joint. If applying glyphosate to ryegrass greater than six inches increase the rate. Apply glyphosate at a minimum rate of 1.5 pounds acid equivalent per acre or 44 fluid ounces of a Roundup branded product. If plants become too large apply glyphosate up to 2.5 pounds acid equivalent per acre. Purdue University data shows adding Sharpen at 1 ounce per acre with glyphosate at 1.5 pounds per acre can improve ryegrass control. Mixing atrazine or metribuzin with glyphosate may reduce control due to antagonism. With the continued cold weather it will be important to allow the ryegrass to resume growth and allow several days of temperatures above 55 to 60 degrees F before spraying. Apply glyphosate when plants are actively growing and daytime temperatures are above 55°F. Do not spray if night time temperatures go below 40 degrees F. High rates of paraquat plus atrazine applied before corn can effectively control ryegrass. Apply the paraquat plus atrazine mixture at 20 gallons per acre.

Cereal rye and wheat are much easier to control. However the recommendation is still to terminate these crops early. Apply glyphosate at least at 0.75 pounds acid equivalent per acre or 22 fluid ounces per acre of a Roundup branded product for rye and 1.125 pounds acid equivalent per acre or 32 fluid ounces per acre of a Roundup branded product for wheat. If plants get over 18 inches in height or tank-mixing other products with glyphosate, increase the rate to 1.125 to 1.5 pounds acid equivalent per acre.

For control of crimson clover and Austrian winter pea apply glyphosate at 1.125 pounds acid equivalent per acre plus 2,4-D ester at 1 pint per acre. Red clover is more difficult to control. Plants should have some good growth on them before applying herbicides. For red clover, apply glyphosate at 1.5 pounds acid equivalent per acre plus 2,4-D ester at 1 pint per acre. Control may not be complete, so scout to determine if an early postemergence application of glyphosate is necessary. Another option to more effectively control red clover in the burndown is to apply dicamba at 8 fluid ounces per acre plus 2,4-D ester at 1 pint per acre plus glyphosate at 1.125 pounds per acre. However soybean planting must be delayed 14 days following one inch of rain, so be careful. Be sure the seed slot is closed for corn and soybean as injury will occur. It is advised to delay planting of corn at least 7 days to reduce injury risk.

Scout fields for weeds prior to herbicide application to determine the need for additional herbicides.

SUMMARY OF 2017 CROP
PRODUCTION IN AUGLAIZE COUNTY

At the end of February the United States Department of Agriculture released the crop production data by counties for 2017. I will discuss some of this data.

The 2017 crop season started off early and great, but hit the skids the end of May and early June causing large amounts of replanting. Then constant rains fell in June and early July, making things difficult to get done and causing crops to deteriorate a little. Despite all of the stresses for 2017, crop yields were not too bad.

In 2017, there were 3.13 million acres of corn harvested in Ohio with an average yield of 177 bushel per acre. In Auglaize County, 66,500 acres of corn were harvested. This represents 2.1% of Ohio corn acres harvested. There were 500 fewer acres of corn harvested in 2017 compared to 2016 and a decline of 6,500 acres from the high in 2012. Corn yield for Auglaize County in 2017 was 172.9 bushels per acre, 4.1 bushels below the state average. This is unbelievable based upon how our weather conditions were! This was the second highest corn yield for Auglaize County in the last ten years! The highest yield was 178.2 bushels per acre in 2014.

In 2017, there were 5.09 million acres of soybean harvested in Ohio with an average yield of 49.5 bushels per acre. Auglaize County harvested 98,900 acres in 2017. This represents 1.9% of harvested soybean production for the state of Ohio. This was the greatest number of soybean acres harvested in the history of crop production in Auglaize County! Soybean yield for Auglaize County in 2017 was 50.6 bushels per acre, 1.1 bushels per acre above the state average. This was the fourth highest soybean yield for Auglaize County in the last ten years. This is not too bad for the extended dry period in the end of July and early August. Soybean yield was 58.9 bushels per acre in 2014, 53.2 in 2016, and 52.1 in 2015.

In 2017, there were 460,000 acres of wheat harvested in Ohio with an average yield of 74 bushels per acre. Auglaize County harvested 10,500 acres of wheat in 2017. This represents 2.3% of harvested wheat production in the state of Ohio. There was a decline in wheat acreage by 3,000 acres compared to 2016. The amount of wheat acres planted in 2017 was the lowest in the last 10 years and likely the lowest ever. This is 18,100 fewer acres than 2008 that had the greatest number of acres (28,600) in the last ten years. Wheat yield for Auglaize County in 2017 was 68.3 bushels per acre, 5.9 bushels lower than the state average. This was the fourth highest wheat yield in the last 10 years. The highest wheat yields in the last ten years was 87.0 bushels per acre in 2016, 85.7 bushels per acre in 2014, and 77.8 bushels per acre in 2012.

According to the National Ag Statistics the average cash rent for Ohio was $152 per acre in 2017. This was a $2 per acre increase over 2016 and 2015.

FROST SEEDING LEGUMES AND GRASSES

Soils in our area have a period of thawing and freezing during the transition from winter to spring. This process can disturb and mix the upper soil layer by the swelling and shrinking properties of clay, which is abundant in many of our soils.

Farmers take advantage of this activity by a practice that is called frost seeding. Frost seeding is the process of applying seed over an existing pasture or hay field in late winter or early spring so seed can be moved into the soil during the thawing and freezing activity.

The objective is to renovate, fill in dead spots, and improve the overall quality of the pasture without killing existing plants and starting over. Farmers may also frost seed into wheat fields to have forage for livestock after wheat harvest.

Forage seeds need to have good contact with the soil and be near the soil surface for germination and early growth. Frost seeding requires areas of bare soil to be successful.

The seeding will fail if there is too much vegetation and the seed gets caught in the residue. A farmer may prepare for a frost seeding the previous fall by reducing vegetation without killing the pasture by close grazing, low mowing, or light tillage.

Legumes are the most common species used for frost seedings. Forage legumes have excellent nutritional value for livestock and have the ability to obtain nitrogen from the atmosphere and release it for plant use. Also legume seeds are heavier than grass and have a better chance of getting through the vegetation to bare soil. Perennial ryegrass and orchardgrass frost seed the most successfully with bromegrass being intermediate and timothy and reed canarygrass the least successful.

Red clover is the most common forage legume used for frost seedings. It has good seedling vigor and tolerates a wide range of soil pH, moisture, and fertility conditions.

Red clover grows as a short-lived perennial typically lasting for two years. Newer varieties survive longer but seed costs will be higher.

Birdsfoot trefoil may be mixed with red clover. It is a persistent perennial but slow to establish and may not become a major part of the pasture until the second year after the frost seeding. However, this may work well since red clover is declining the second year.

Another popular legume is white clover. White clover is a perennial clover that thrives in the cool spring weather. It tends to be a short legume and may not get adequate light for optimum growth when seeded with taller grasses. However, companies have developed newer varieties that tend be more upright.

Frost seeding rates vary among forage species. The smaller the seed the lower the seeding rate. For example the seeding rate for white clover is two to three pounds per acre and the rate for red clover is six to eight pounds. Seed perennial ryegrass at two to three pounds/A, orchardgrass at two to four pounds per acre, and smooth bromegrass at eight to ten pounds per acre.

A bacterial inoculum should be included in the frost seeding if the forage legume has not been grown in a pasture for several years. Inoculum insures the presence of Rhizobia bacteria, which gives the plant roots the ability to fix atmospheric nitrogen. The inoculum is generally added as a seed treatment by the seed supplier.

Common (generic) red clover used to be grown in the area and was readily available at a lower cost than branded seed. Seed production of red clover has been declining in our area for the past decade.

The cost of red clover seed has increased as a result of lower supplies of common red clover seed and the larger demand for legumes as a cover crops.

Higher seed costs and the risk of establishment failure has caused the practice of frost seeding to become less common in our area. However, there are still farmers who will take advantage of the spring thaw and freeze cycle and use frost seeding to improve pastures and provide livestock with high quality forage.

The next three to four weeks is generally the time that farmers will try to frost seed. However, the unseasonably warm temperatures that we are experiencing and based upon the forecast, may make frost seeding more challenging this year and shorten the window for the thaw-freeze activity of the soil.

WHAT IS GIBBERELLA EAR ROT
AND VOMITOXIN?

Gibberella ear rot is caused by the fungus Fusarium graminearum, the same pathogen causing head scab of wheat and stalk rot of corn. Gibberella ear rot was fairly prevalent in 2016, but not in 2017. The fungus overwinters on corn and wheat residue. The spores are produced on the corn and wheat residue throughout the growing season and are dispersed by the wind travelling for some distance. Spores infect the ear through the silk channel, causing a pinkish to reddish to white mycelial growth between and over corn kernels at the tip of the ear. The mold can continue to grow down the ear, sometimes reaching the base of the ear. Infection usually only affects the upper third of the ear. The husks and silks of severely infected ears can adhere tightly to the ear.

Cool, wet weather during the first 21 days after silking allows the disease to be most prevalent. Extended periods of rain in the fall, delaying dry down, increases the severity of the disease.

Giberella ear rot is most prevalent in fields planted to corn following corn or wheat, especially in no-tillage production.

The disease causes corn kernels to shrivel and have lower test weight. Start scouting for ear molds as the corn reaches maturity. Visit five spots in the field randomly and pull the husks back on 20 ears at each spot looking for the presence of molds. If giberella ear rot is found, harvest those fields early and before fields without diseased ears and keep the corn separate. The growth of the fungi needs to be stopped as soon as possible. This can be accomplished by harvesting and drying the corn to below 15% moisture and reducing the heat as quickly as possible. It is recommended to clean the corn to remove as much of the diseased kernels and fines as possible.

One problem with corn containing giberella ear rot is that livestock animals will refuse to eat feed made from the corn. The biggest problem however is the presence of chemical toxins, called mycotoxins, produced by the fungi. Three of the most common mycotoxins produced by the fungi are deoxynivalenal (DON), also called vomitoxin, zearalenone, and T-2. The vomitoxin is the most common of the three toxins.

Vomitoxin increases as the severity of giberella increases and may accumulate in healthy-looking grain. Vomitoxin causes animals to vomit which is how it gets its name. The vomitoxin is stable at high temperatures, is water soluble, and persists in storage and throughout processing. Vomitoxin is harmful to humans and animals, especially swine. Food for humans and feed for swine must not contain more than 1 ppm in the total diet. Therefore 20% of a feed ration may contain a 5% level of vomitoxin. Feed for poultry and ruminant animals may contain a total diet of 5 ppm of vomitoxin.

The other major concern with vomitoxin is at the ethanol mill. When the corn grain is processed the remaining material, called distiller’s dried grains with solubles (DDGS) is one third the weight of the grain. Since the vomitoxin is heat stable and water soluble the vomitoxin is concentrated three fold in the DDGS. The DDGS are used as a feed source making it difficult to sell with the increased level of vomitoxin.

What can a farmer do now with corn containing vomitoxin? If the corn was not cleaned at harvest, clean the corn really well and mix in corn having no vomitoxin. Call different grain elevators asking how much vomitoxin they will allow. Depending upon the use of the corn at the facility, they may be able to handle higher concentrations than other facilities.

The best strategy to reducing the risk of having Gibberella ear rot is to visit with your seed supplier and choose hybrids that are resistant to the pathogen. Fungicides have not been proven to be an effective management strategy at this time. Another management strategy is to bury corn and wheat residues and plant soybeans, however this is not a full proof approach since the spores can travel long distances.

WHAT ARE SOYBEAN CYST NEMATODES?

Soybean cyst nematode is a microscopic roundworm that feeds on soybean roots. It is about 1/64th inch in length. The scientific name for soybean cyst nematode is Heterodera glycines.

Soybean cyst nematode was first identified in Ohio in 1987. It can be found in nearly every Ohio county.

There are three major life stages of soybean cyst nematodes: egg, juvenile, and adult. Soybean cyst nematode can reproduce rapidly because it can complete its life cycle in Ohio in 24 to 30 days. Therefore there can be three to five generations within a growing season.

The juveniles hatch from eggs and search for soybean roots or roots of other host plants. Juveniles travel only short distances in the soil before entering a root. If it finds no root the soybean cyst nematode juvenile dies from lack of food. Water can aid in the dispersion of the juvenile nematodes. After penetrating the root, the nematode feeds on cells in the vascular tissue. The feeding site is established by the secretion of digestive enzymes that stimulates the development of enlarged cells.

The cyst stage is the body of the dead female nematode filled with eggs. The cyst is highly resistant to many adverse conditions and serves to protect the developing eggs and young nematode larvae for many years. One cyst holds about 250 eggs, although it is variable. Before the female dies it will release some eggs outside its body which will hatch anywhere from days to months later, but will not survive the winter. The majority of the eggs are found in the cyst which may live for many years. Usually, 50 percent of the eggs produced by a female hatch each year, thus the population may drop significantly after several years if there are no susceptible host plants available.

Symptoms of soybean cyst nematode in the field are highly variable. Symptom development depends upon population density of nematode, presence of other pathogens, soil nutrient status, field history of planting resistant varieties, and rainfall. Circular to oval patches of dying, stunted, and yellowed plants are symptoms of a severe population. Moderate symptoms include patches of stunted plants and lower than desired yields. Symptoms of soybean cyst nematode can be confused with nutrient deficiencies, injury from herbicides, soil compaction, and other diseases.

The soybean cyst nematode females can be found clinging to the sides of the soybean roots throughout summer. The female can be identified by it’s swollen body full of eggs looking like a small white pearl or lemon on the root. To look for the females, carefully dig the plants and gently shake it or wash the soil off the roots, looking for bright white to yellow females. The females will be about the size of a sand grain.

There are 16 races of soybean cyst nematodes. Knowing the race is very important to helping manage the population. It is also important to know the density of the eggs and cysts in a field to assist in management. To gather this information, soil samples need to be collected. It is best to collect soil samples in the fall after soybean harvest to know what the maximum population is, but samples can be taken at other times of the year. Collect 10 to 20, 6 to 8 inch soil cores for every 10 to 20 acres. Composite the cores for each 10 to 20 acre area and place 1 pint of soil into a soil bag or plastic zippered bag. Store the sample in a cool, dark place until shipped.

Soybean cyst nematode is a serious problem. Soybean yield loss can occur when there are only 40 to 200 eggs per 100 to 200 cc of soil, considered to be a trace population. Sixteen to 18 bushels per acre yield loss can occur with susceptible soybean varieties with an egg count of 2000 to 5000 eggs per 100 to 200 cc of soil.

The best strategy to reduce soybean cyst nematode populations is to plant non-host crops, such as alfalfa, wheat, and corn. The more years these crops are grown the greater the reduction of soybean cyst nematode populations.

Despite the rotation of crops, weeds can be host to the soybean cyst nematode, so keeping certain weeds out of a field for as much of the growing season as possible is important. The list of weeds acting as hosts to soybean cyst nematode include common and mouseear chickweed, common mullein, henbit, pokeweed, common purslane, wild mustard, purple deadnettle, field pennycress and shepherd’s-purse. Purple deadnettle is the greatest host.

Another management strategy is to plant resistant soybean varieties. However the resistance is starting to break down with the most common source of PI88788. Switch to soybean varieties having Hartwig (PI437654) or Peking/CystX source of genetics.

Other management strategies include maximizing plant growth through fertility and having soil pH below 7.1, optimize planting and harvesting dates for maturity group, optimize drainage, manage sudden death and brown stem rot, and prevent the introduction of soybean cyst nematode through soil movement.

CHOOSING CORN HERBICIDES

It is that time of the year when farmers are choosing their herbicides and other pesticides for this coming year’s crop. Much thought goes into choosing the right herbicide, such as effectiveness, cost and many other factors.

Most of the corn planted in the county is after some spring tillage, but there is still some no-tillage corn. For no-tillage corn apply glyphosate at 1.125 to 1.5 pounds acid equivalent per acre (32 to 44 fluid ounces per acre of Roundup PowerMAX) plus 2,4-D ester (4 pound per gallon product) at 1 pint per acre. This combination is the most broad-spectrum, but it can be a little week on marestail. It is best to apply this combination 7 days before planting to minimize corn injury, but it can be applied after planting, but before corn emergence if you are willing to accept the injury that may occur.

There are many effective preemergence herbicides for corn. The most comprehensive products or combinations include Acuron plus atrazine, Lexar, Lumax, Cinch ATZ plus Instigate, Resicore plus atrazine, Corvus plus atrazine, Balance Flex plus atrazine premix (Bicep II Magnum or Harness Xtra as examples), SureStart plus atrazine, and Harness MAX plus atrazine. These comprehensive products have the potential to control weeds all season long. Weeds that can escape these herbicides include annual grasses such as giant foxtail and fall panicum, giant ragweed, and waterhemp. When these products are applied in a burndown prior to emergence of corn include a methylated seed adjuvant.

All of these preemergence herbicides can be applied early postemergence should the weather not cooperate. Instigate, Balance Flex, and Corvus must be applied no later than 2-collar corn. Since Instigate, Corvus, and Balance Flex must be applied to really small corn, fields will need to be scouted to ensure no weeds have emerged after the application. One strategy to reduce the chances of late weed emergence is to include atrazine at 2.0 pounds active ingredient per acre as long as you do not have highly erodible land and did not apply any in the preemergence application. You can only apply a total of 2.5 pounds active ingredient per acre of atrazine for the season. All other products mentioned above can be applied up to 11-inch corn. Be sure to check the labels to know what adjuvants need to be mixed with these products. Mixing a high rate of atrazine with these products will help from needing to apply a second postemergence application.

Atrazine premixes such as Bicep II Magnum and Harness Xtra are cheaper options, but usually do not provide season-long control, especially for annual grasses, giant ragweed, velvetleaf, and waterhemp. A planned postemergence program is necessary with these products.

If Roundup Ready corn is planted, glyphosate applied postemergence will effectively control most of the weeds, exceptions will be marestail, giant ragweed, waterhemp, and maybe common ragweed due to resistance. The most effective postemergence broadleaf herbicides to control these resistant weeds include Callisto Xtra, dicamba plus atrazine, DiFlexx Duo, Impact plus atrazine, and Laudis plus atrazine. The use of atrazine means applications must be applied before 12-inch corn, which may be too soon to control waterhemp season long. Only the DiFlexx Duo can be applied to corn larger than 12-inch which will provide more effective control of waterhemp. The next most effective postemergence herbicides that will control the glyphosate resistant weeds and allow for applications to larger corn include Capreno and Status. To improve weed control with Status apply it at 8 fluid ounces per acre.

If Balance Flex, Corvus, or Instigate are applied preemergence, then other HPPD inhibiting herbicides containing the active ingredient in Callisto, Impact, or Laudis can’t be applied postemergence.

For Non-GMO corn, the preemergence herbicides mentioned above can be used. There are two strategies, just use a atrazine premix or a low rate of a comprehensive preemergence program and automatically apply postemergence herbicides as they will most likely be needed or use a high rate of a comprehensive herbicide program and likely not need a postemergence treatment, but scout to make sure.

Pre-mixtures that will control grass and broadleaf weeds in non-GMO corn include Capreno and Revulin Q. Impact plus atrazine is a tank-mixture that will control both grass and broadleaf weeds. Accent Q and Steadfast Q control grasses and can be mixed with the above mentioned postemergence broadleaf herbicides to control both grasses and broadleaves.

TIME TO CHOOSE HERBICIDES
FOR 2018 SOYBEAN CROP

It is the end of the year and time to make end of year crop input purchases at reduced prices and to reduce any tax burden. Choosing soybean herbicides for 2018 is very critical to maximizing weed control.

Based upon the 2017 weed survey, only eight percent of soybean fields were weed free at harvest time in Auglaize County, meaning some work needs to take place to improve weed control. The top three weeds in soybean fields were giant ragweed at 56 percent, waterhemp at 47 percent, and marestail at 40 percent. Waterhemp is the most concerning weed. Populations continue to grow. In 2016 waterhemp was found in 45 percent of fields west of I-75 and 14 percent of fields east of I-75. In 2017 waterhemp was found in 58 percent of fields west of I-75 and 32 percent of fields east of I-75. Significant changes in waterhemp management are necessary to manage this weed in soybean in 2018.

If planting Roundup Ready soybean or Xtend soybean and not planning to apply dicamba products postemergence, then purchase fomesafen (known as Flexstar) to control waterhemp and giant ragweed. Fomesafen will not control marestail. Fomesafen needs to be applied at 1.3 pints per acre. When purchasing fomesafen also purchase a methylated seed oil adjuvant or a high surfactant methylated seed oil adjuvant to apply at a rate of 1.5 to 2.0 pints per acre. The methylated seed oil must be used with fomesafen to maximize herbicide activity. When applying fomesafen, the spray volume needs to be at 20 gallons per acre and choose nozzles that produce fine to medium spray droplets.

To control volunteer corn in all types of soybean and to control barnyardgrass and yellow foxtail in LibertyLink soybean purchase clethodim (known as Select) or Fusion. Apply clethodim at six fluid ounces per acre (2EC products) or 9 fluid ounces per acre (1EC products) or Fusion at six fluid ounces per acre to control volunteer corn. To control barnyardgrass and yellow foxtail, apply clethodim at eight fluid ounces per acre (2EC products) or 12 fluid ounces per acre (1EC products) or Fusion at eight to ten fluid ounces per acre.

Residual control of marestail, giant ragweed, and waterhemp is critical to improving postemergence control. For residual control of marestail apply products containing sulfentrazone (known as Spartan) or flumioxazin (known as Valor) and add metribuzin (known as Sencor). These products will also provide good control of waterhemp. To assist in residual control of giant ragweed be sure the premixes include chlorimuron (known as Classic) or cloransulam (known as FirstRate).

In fields with moderate to heavy waterhemp pressure the addition of metolachor (known as Dual), Zidua, Outlook, or Warrant should be considered. Adding these herbicides should preempt the need for a second postemergence herbicide application.

For burndown herbicides apply glyphosate (known as Roundup) at 1.5 pounds acid equivalent per acre plus 2,4-D ester at 1.0 pound acid equivalent per acre. This combination is usually enough to control weeds in a field, but sometimes control has not been adequate and the combination must be applied 15 days before planting. Other burndown herbicides include Sharpen, paraquat (known as Gramoxone), and glufosinate (known as Liberty), but there are limitations to these products.

If planting LibertyLink soybean prepare to apply glufosinate two times. The second application should only be necessary in fields with moderate to heavy giant ragweed and/or waterhemp pressure. Apply glufosinate at 32 fluid ounces per acre.

If you are planning to plant Xtend soybean, there are three dicamba products to choose from. They are XtendiMAX, Engenia, and FeXapan. These products are now restricted use pesticides, so a pesticide license is necessary to apply these products. In addition there is a special training you must attend to use these products. Remember that only approved pesticides can be mixed with these dicamba products. At this time, Engenia has the most tank-mix partners. Apply XtendiMAX and FeXapan at 22 fluid ounces per acre and Engenia at 12.8 fluid ounces per acre.

GENETICALLY MODIFIED TRAITS IN

CORN AND DO I NEED THEM?

The first commercially available genetically modified trait was resistance to glyphosate (Roundup) in soybean in 1996. Today there are eight genetically modified traits commercially available in corn.

The traits in corn include resistance to glyphosate (Roundup), glufosinate (Liberty), 2,4-D and “fop” chemistry, European corn borer, corn rootworm, and corn earworm, drought tolerance, and the Viptera trait which has resistance to European corn borer, corn earworm, armyworm, and cutworm species. Therefore, there are three herbicide resistance traits (glyphosate, glufosinate, and 2,.4-D and “fop” chemistries), four insect resistance traits, and one drought tolerance trait. The insect resistant traits are sometimes called Bt traits because they produce the Bt toxin to control caterpillars.

The 2,4-D and “fop” chemistry trait is the newest one available. It confers resistance to 2,4-D a broadleaf weed only herbicide and resistance to “fop” herbicides which are grass herbicides usually applied to broadleaf crops. Do you need to plant a glyphosate-, glufosinate- or 2,4-D and “fop” chemistry-resistant corn hybrid? There currently are enough corn herbicides available to effectively control annual weeds without the use of glyphosate, glufosinate or 2,4-D and “fop” chemistry. With the frequency of glyphosate-resistant weeds, other corn herbicides are necessary anyways, so the utility of glyphosate-resistant corn is greatly reduced. Glyphosate- glufosinate- and 2,4-D and “fop” chemistry-resistant hybrids provide greater crop safety than some other corn herbicides. Glufosinate-resistant hybrids could be a viable option, but we should be using that trait in soybean. Glyphosate and glufosinate herbicides are fairly non-selective herbicides meaning they kill most broadleaf and grass weeds. Glyphosate more effectively controls perennial weeds than all other corn herbicides. Glyphosate is the safest and most cost effective postemergence herbicide to control grass weeds in corn.

European corn borer populations are lower today than what they have been historically, although there was a significant population in some areas in 2015 that caused damage to non-GMO corn hybrids. European corn borer has two generations during a growing season making it difficult to scout and widens the window for damage. If an infestation occurs in non-GMO corn, timely insecticide applications are necessary before the larvae enter the corn plant, otherwise there is no control. There are many effective insecticides to control European corn borer. Resistance to European corn borer is the most cost-effective and stress-relieving way to manage European corn borer.

Corn rootworm populations are very very low today compared to historically. In addition, the variant of the western corn rootworm that lays eggs in soybean is nearly non-existent in our area. Another factor reducing the chance for corn rootworm after soybean is the use of insecticides in soybean. If corn is grown after soybean, corn rootwoom should not be a problem. Some of the insecticide seed treatments in corn reduces corn rootworm densities. Therefore, corn rootworm-resistant hybrids provide little benefit in our area.

Corn earworm, armyworm, and cutworm are minor pest problems in corn in our area. However there are times that armyworm and cutworm populations can reach significant levels. This has been the case in some fields in the last two years mostly where corn is planted into a grass cover crop. There are effective insecticides to managing these pests, but timely scouting is necessary. A resistant hybrid would reduce the need for scouting and stress.

Research in Kansas showed that when adequate rainfall was received the drought tolerant corn hybrids did not improve yield, however when moisture stress was present, corn yields improved five to seven percent. Drought is less frequent in Ohio than Kansas. In our area we usually receive adequate to surplus rainfall, so will the added expense of the seed pay for itself? However, weather conditions are more extreme today, so drought may occur more frequently.

Non-GMO corn can be successfully grown today, but it requires more management to control all pests, but do we have enough high yielding non-GMO hybrids available today?

SULFUR APPLIED TO CORN AND
LOCAL RESEARCH RESULTS

There is much discussion about the need to apply sulfur to corn. Sulfur is an essential nutrient for all plants being used to make four amino acids, two of which are used to make proteins. Sulfur is considered a secondary nutrient, because more of it is needed than micronutrients, like manganese, but less of it is needed compared to primary nutrients like nitrogen. One research trial showed corn residue was made up of 0.07% sulfur, so at a 200 bushel per acre corn crop at 4.7 tons of stover per acre there was 7 pounds of sulfur in the residue. In addition to that corn grain contains 0.5 pound of sulfur for every 10 bushels of grain, so a 200 bushel per acre corn crop will remove 10 pounds of sulfur.

One of the reasons for concern about sulfur deficiency is due to the amount of sulfur deposited from the atmosphere in rain. Prior to 1990 8 to 9.5 pounds of sulfate was deposited to the land in rainfall. In 2009, only 2.5 to 4.0 pounds of sulfate was deposited. However; there are other sources of atmospheric sulfur which include oceans, soils, and volcanic activity. Other reasons for sulfur deficiencies include higher yields, no-tillage, early planting, and heavy residues. Cold and wet soils reduce microbial activity; therefore, releasing less sulfur for the plant so deficiencies are most often seen early in the growing season.

Sulfur deficiencies are most often observed in coarse textured low organic matter soils. As organic matter and clay content increases sulfur deficiency is less likely to occur. Soil sampling is not an effective way to predict sulfur deficiency because it is a fairly soluble nutrient similar to nitrogen, so what is present at the time of soil sampling is unlikely to be present when the plant needs it. Tissue sampling is the best way to determine if a plant is deficient in sulfur. Tissue samples greater than 0.2% sulfur and a nitrogen to sulfur ratio less than 12:1 is considered adequate. Tissue samples less than 0.12% sulfur and a nitrogen to sulfur ration greater than 20:1 is considered deficient.

A research trial looking at sulfur applied to corn was established this season in Auglaize County. The trial had three treatments, no sulfur, 20 pounds of sulfur per acre applied at planting in a two inch by two inch band, and 20 pounds of sulfur per acre at planting followed by 20 pounds per acre of sulfur applied at sidedressing. The trial had three replications. The source of sulfate was ammonium thiosulfate.

The soil in the research trial is composed mostly of Blount silt loam, but has a little Pewamo and Glynwood silt loam. The soil organic matter in 2013 was an average of 3.1%. Soybean was the previous crop. The field was chiseled in the fall and field cultivated twice in the spring, once before the application of potash and a second to incorporate the potash. The corn was planted May 19, 2017 at 33,000 plants per acre. A total of 160 pounds of nitrogen per acre was applied with 40 pounds per acre applied at planting and 120 pounds applied at sidedressing. The sidedress application occurred on June 28, 2017 when the corn was V7 to V8 in growth stage and incorporated to a 3 inch depth.

Leaf tissues were collected at R1, stand counts were taken just before harvest, and grain samples taken at harvest. The trial was harvested October 26, 2017.

Harvest stand counts were not different at 28,111, 29,000, and 29,222 plants per acre for 0 sulfur, 20 pounds per acre of sulfur, and 20 followed by 20 pounds per acre of sulfur, respectively. There was no difference in grain moisture or test weight between the treatments. Grain yield was 198.3, 202.6, and 202.9 bushels per acre for 0 sulfur, 20 pounds per acre of sulfur, and 20 followed by 20 pounds per acre of sulfur, respectively. Despite the numeric advantage to applying sulfur there was no statistical difference between these treatments! The amount of sulfur in the leaf tissue was between 0.23 and 0.24 for all treatment which are not different and above the adequate level mentioned above.

Based upon the results of this one trial there appears to be no advantage to applying sulfur to corn either once at planting or twice during the season.

2017 WATERHEMP MANAGEMENT
RESEARCH RESULTS

This past growing season I conducted two waterhemp research trials, one in LibertyLink soybean and the other in Xtend soybean. The density of all waterhemp plants in these trials were light to moderate and variable across each trial. In addition, the number of glyphosate-resistant waterhemp in the Xtend trial was very low to low and highly variable throughout the trial area. This variability made it difficult to evaluate plots and to have treatment separation when analyzing the data. The data is still strong enough to learn some insights.

Both trials were designed the same way except for the postemergence treatments. The trials were planted no-tillage with Liberty being applied on May 16, 2017 to control existing weeds along with residual herbicides. The residual herbicides applied included no residual herbicides, Valor XLT at 4 ounces per acre, Valor XLT plus metribuzin 75 DF at 8 ounces per acre, Fierce XLT at 4.5 ounces per acre and Valor XLT followed by Zidua at 2 ounces per acre with the postemergence herbicide. The soybeans were not planted until June 2, 2017. The postemergence herbicides applied included Liberty at 29 fl oz/A in the LibertyLink soybean trial and Roundup WeatherMAX at 32 fluid ounces per acre plus Flexstar at 1.3 pints per acre or XtendiMAX at 22 fluid ounces per acre in the Xtend soybean trial.

Postemergence herbicides were applied at two different timings.  The targeted heights were 3-4 inch and 6-8 inch weeds.  Some waterhemp plants were a little taller than the targeted heights at some of the timings, but the majority of plants were within these two ranges.

What did we learn from these trials? 1. Waterhemp was just starting to emerge on May 16, 2017 and continued germinating into early August; 2. There was no difference in waterhemp control from any of the three preemergence treatments with control ranging from 78 to 84% (0% being no control and 100% being complete control) on June 26 just before the postemergence applications. Therefore postemergence herbicides are necessary; 3. The preemergence herbicides delayed postemergence applications from 13 to 16 days for the 3-4 inch timing and 12 to 19 days for the 6 to 8 inch timing compared to no preemergence herbicide; 4. On August 15th in both trials, preemergence followed by postemergence herbicides provided more effective waterhemp control compared to no preemergence herbicide; 5. The addition of Zidua to Liberty following a preemergence herbicide provided 99% waterhemp control compared to Liberty alone following preemergence herbicides providing only 90% control; 6. Liberty can provide very effective control of existing plants at the time of the application similar to XtendiMAX and Flexstar, however since Liberty has NO residual activity waterhemp can emerge after the application, requiring a second postemergence application or the addition of a residual herbicide in the first application; 7. Flexstar and XtendiMAX provided residual waterhemp control, but Flexstar provided more control. Because of this residual control the addition of Zidua was not needed based upon this one trial. However, I would not expect Flexstar and XtendiMAX to provide such a high level of residual control every season, making the addition of a residual herbicide in the postemergence application beneficial; 8. Flexstar and XtendiMAX mixed with glyphosate can improve waterhemp control compared to glyphosate alone; 9. Apply herbicides to 4-6 inch waterhemp plants and certainly not greater than 8 inches; 10. Some waterhemp plants survived Flexstar, XtendiMAX, and Liberty indicating the potential for resistant plants in the future.

I asked the cooperator to harvest one pass of the soybeans in the middle of each trial to get a yield estimate. The LibertyLink soybean yielded 49.5 bushels per acre and the Xtend soybean yielded 46.5 bushels per acre. This should dispel the myth that LibertyLink soybeans do not yield as well!

ANNUAL WEED SURVEY RESULTS

Every fall Extension Educators around the state of Ohio drive around their county and evaluate the weed control in soybean fields. This is the third year that I have done this and John Smith had done this before me.

This year I drove a 95 mile route in early September. I started at the Darke, Mercer, Shelby, and Auglaize Counties line and went north to Barber-Werner Road, then went East to Worrel Road then south to Gutman Road then east to New Knoxville, and then North to State Route 197.

Weed control is evaluated as weed free, occasional plants (occasional single plants or a small patch), large patches (patch of 8 or more plants scattered in the field) and widespread (numerous patches or individual plants across the field) for each weed species present in the field.

I evaluated 358 fields in my driving route. This year only 8% of fields were weed free. In 2016 11% of fields were weed free, in 2015 18% of fields were weed free and in 2013 27% of fields were weed free. This steady decline in weed free fields is due to the increased presence of glyphosate resistant weeds and tough weather conditions. I further evaluated the occasional fields observing which fields had 3 or fewer broadleaf plants in them which I consider nearly weed free. If you take the percentage of these nearly weed free fields and add them to the number of weed free fields, then 21% of fields were nearly weed free. In 2016 22% of fields were nearly weed free (<3 plants).

Giant ragweed was the most prevalent weed in soybean fields this year at 56% of fields. In 2016, giant ragweed was the second most prevalent weed at 49% of fields. This is quite an increase. This increase was likely due to late germination of plants caused by the rainy weather and the increased presence of glyphosate-resistant giant ragweed. Sixteen percent of fields had giant ragweed at the large patch and widespread levels.

The second most prevalent weed in 2017 was waterhemp which was present in 47% of fields. Waterhemp moved up on the list as it was the third most prevalent weed in 2016. This compares to 32% of fields in 2016, 21% of fields in 2015, and 6% of fields in 2013 (which was listed as pigweed species, but I’m sure there was some waterhemp included). Nineteen percent of soybean fields had waterhemp at the large patch and widespread levels, indicating very concerning levels of waterhemp. Waterhemp was present in 58% of fields west of Interstate 75 in 2017 compared to 45% of fields in 2016 and 32% of fields east of I-75 in 2017 compared to 14% in 2016. This drastic increase in waterhemp east of I-75 will make it very difficult to reduce waterhemp populations into the future, unless very drastic measures are taken next year to control waterhemp.

Marestail was the third most prevalent weed species in fields this year at 40% compared to being first place last year at 51%. This is a great decline and I believe this is due to the increased amount of fall applications last year.

Other weeds in order of most prevalent to least prevalent included volunteer corn at 28%, annual grasses such as giant foxtail and others at 15%, common lambsquarters at 4%, velvetleaf at 4%, smooth pigweed at 3%, common ragweed at 2%, morningglory at 1%, wild carrot at 1%, common cocklebur at 1%, and shattercane at less than 1%.

The weediest fields were south of St. Marys as 31% of fields had four or more weed species present.  All other areas of the county had fewer than 15% of fields having four or more weed species.

Drastic measures must be taken to manage weeds in Auglaize county, especially regarding waterhemp. The days of a preemergence herbicide followed by glyphosate alone are over for most people. A good preemergence herbicide followed by Flexstar plus glyphosate, Liberty applied to LibertyLink soybean, or dicamba plus glyphosate applied to Xtend soybean are the only effective programs in soybean.

FALL FERTILIZATION

It is that time of year to be considering applications of fertilizer in preparation for next year’s crop. Before applying fertilizer, take a soil sample and get it analyzed or utilize a soil test report no more than two years old. In the current grain marketing situation, it is important to not under fertilize as this reduces yields and profits and not over fertilize which unnecessarily adds to the cost of production.

Phosphate fertilizer is to be applied based upon the soil test value in parts per million of phosphorus and realistic yield goals. If phosphorus levels are reported in pounds per acre then divide the number by two to get parts per million. According to the Tri-State Fertility Guide, the phosphorus maintenance range for corn and soybean is between 15 and 30 parts per million based upon Bray P1 and between 28 and 46 parts per million based upon Mehlich III. Within the maintenance range only the amount of phosphorus removed by the crop needs to be applied and if at the upper range the full rate is not necessary. The amount of phosphate (P2O5) removed from corn is 0.37 pounds per bushel, soybean 0.8 pounds per bushel, and wheat grain 0.63 pounds per bushel. No additional phosphate fertilizer is recommended once the Bray P1 and Mehlich III soil test levels are greater than 40 and 58 parts per million, respectively. For wheat and alfalfa, the maintenance range is between 25 to 40 parts per million based upon Bray P1 and 40 to 58 parts per million based upon Mehlich III. No phosphate fertilizer is recommended when the Bray P1 and Mehlich III soil test levels are above 50 and 79 parts per million, respectively. Forty years of research from The Ohio State University, Purdue University, and Michigan State University shows there is no positive yield response from phosphate fertilizer applied beyond Bray P1 levels of 40 parts per million when growing corn and soybean or 50 parts per million when growing wheat and alfalfa. As an example if you have a soil test value of 25 parts per million Bray P1 and a yield goal of 200 bushels per acres for corn, apply 75 pounds of actual phosphate per acre.

Potash is applied based upon soil test values, realistic yield goals and the cation exchange capacity of the soil. The higher the cation exchange capacity and the greater the yield goal, the greater the amount of potash is recommended. Soybeans require more potash than corn. There were a handful of fields showing potassium deficiencies along the field perimeters again this season, so be aware of potassium levels. For soybean, apply potash at 90 pounds actual per acre if the soil test value is between 125 and 155, the cation exchange capacity is 20 meq/100 grams and the yield goal is 50 bushels per acre. For corn, apply potash at 70 pounds actual per acre if the soil test value is between 125 and 155, the cation exchange capacity is 20 meq/100 grams and the yield goal is 185 bushels per acre. Consult the Tri-State Fertility Guide for additional rates.

If you are interested in using a spreadsheet to calculate how much potash or phosphate to apply based upon soil test values, visit the following website and look under Developing Nutrient Recommendations from Soil Test: https://agcrops.osu.edu/FertilityResources

Incorporate fall-applied fertilizer. Incorporation will reduce surface and tile run off. In a research trial, greater than four times the amount of dissolved reactive phosphorus was discharged from a tile following two rain events where phosphate fertilizer was applied to the surface compared to being incorporated. There are tools available now to incorporate potash and phosphate with minimal soil disturbance for no-tillage fields.

HARVEST SAFETY

Harvest season is one of the most dangerous times of the year around the farm. Many activities are happening such as combine operation, transporting grain, filling grain bins, tilling soil, and hauling manure. Because there is a limited window to getting all of these things accomplished, long hours of work happen for much of this time. When fatigue sets in, accidents are more likely to occur.

There are many moving parts on a combine, creating many hazards. When leaving the combine seat, shut off the combine so nothing starts up unexpectedly. Be careful working around the cutter bar. Blow plant residue away from the combine engine and bearings as often as possible, especially if the engine is enclosed. This will reduce the risk for fires. There have been a few combine fires already this fall.

Be sure all lights are working properly on wagons and semi tractors and trailers. This is important for preventing accidents with other individuals. It is important that other drivers know where we are and when we may be turning. Wagons are to have a minimum of a slow moving vehicle sign, yellow flashing lights and two types of reflective stickers. It is also recommended to have solid red lights.

Carefully climb grain bins and do not enter a bin when the grain is being removed.

Cutting corners is usually when accidents happen, so please think ahead and be safe this harvest season.

PURCHASE LIBERTYLINK OR
XTEND SOYBEAN FOR 2018

Now that 2018 seed purchasing has begun, strongly consider purchasing LibertyLink or Xtend soybean. LibertyLink and Xtend soybean are good tools to controlling the increasing density of waterhemp in Auglaize County. A drastic change in managing weeds in Auglaize County is necessary in 2018 to halt the expansion of glyphosate-resistant waterhemp and the LibertyLink and Xtend soybean systems are great strategies.

Before you purchase LibertyLink soybean be sure you are willing to manage the system to obtain complete weed control. To maximize weed control in the LibertyLink soybean system till out all weeds before planting or apply a comprehensive burndown herbicide program in no-tillage fields before planting. A comprehensive soil-applied herbicide is required to obtain early season waterhemp control. Glufosinate (Liberty) will need to be applied at high rates (32 fluid ounces per acre) to small (less than 4 inch) waterhemp at high spray volume (20 gallons per acre) with medium spray droplets, significant spray pressure, and low sprayer travel speed. Scouting will be required after the postemergence application to determine the need for a second application. Glufosinate will also effectively control giant ragweed and marestail (horseweed). If yellow foxtail, barnyardgrass, and/or volunteer corn is present, clethodim will need to be mixed with glufosinate to maximize control.

Before purchasing Xtend soybean be sure you are willing to accept the risk of applying XtendiMAX, Engenia, or FeXapan regarding drift and volatility. Another risk right now with Xtend soybean is whether there will be any label changes to applying the three approved dicamba formulations. EPA may completely pull the registration allowing no applications, restrict the applications to a specified time period during the growing season, or make no changes at all. Waterhemp management in Xtend soybean is similar to LibertyLink soybean except that we must use specific spray nozzles to reduce drift.

SOYBEAN APHIDS

Soybean aphids were reported in Defiance County last week. I have not seen any soybean aphids in Auglaize County as of yet, but two weeks ago an individual said he saw some in a field in Auglaize County. We need to start scouting fields for the presence of soybean aphid, especially the later planted fields.

The soybean aphid is from Asia. The soybean aphid first showed up in the Midwest in 2000. It continued to increase and was a serious problem every other year in western and central Ohio up through about 2013. Since then the aphid population has dwindled and comes in later each year.

Soybean aphids are small, only about 1/16 inch in length. The soybean aphid is yellow-bodied with distinct black cornicles, the appendages sticking up in the rear of the aphid, and may have wings or not.

Soybean aphids are usually found on the undersides of the newest leaves. Soybean aphids move very slow.

Soybean aphids can over winter in Ohio, but this does not seem to be where the majority of the aphid populations arrive into soybean fields. They are most often blown in on air currents from the north and/or west. Minnesota and Ontario, Canada have seen soybean aphids since late June.

Soybean aphids rely on two plants to complete their annual life cycle. Soybean aphids live on buckthorn in late fall until late spring. They live on soybeans the rest of the year. The aphids spend their live as an egg. In the spring, female aphids hatch from these eggs and feed on the buckthorn and reproduce asexually. After two to three generations on the buckthorn they migrate to soybean fields in June. The winged aphids leaving the buckthorn give birth to living aphids instead of eggs leading to fast local outbreaks. As soybeans senesces in the fall, a new generation of winged aphids are produced. These aphids move to the buckthorn to feed and lay eggs to live over the winter.

Soybean aphids have sucking mouth parts allowing them to extract sap or phloem from leaves, stems, and petioles, although leaves are the preferred source. Low levels of aphid populations have little to no influence on soybean growth and development. When soybean plants are stressed, such as by drought, aphid populations can reach extremely high levels and reduce soybean yield by 40%. Only in really bad infestations will plants be stunted or killed.

There are many natural enemies of aphids, including predators, parasitoids, and pathogens. It’s the high levels of natural enemies that drive the aphid population into being an every other year problem. An Asian multicolored lady beetle can consume up to 200 aphids per day. Despite all of these beneficial enemies soybean aphid can repopulate so quickly they can’t keep up.

Scouting for aphids is extremely important to know when to apply insecticides and reduce or eliminate the death of beneficial organisms.

The spray action threshold (time to spray) is 250 aphids per plant when soybean are in the R1 (begin bloom) to R4 (pods ¾ inch long in one of the upper 4 nodes) growth stage. When soybeans are in the R5 (pods filling in one of the upper four nodes) growth stage, aphid populations must be greater than 250 per plant and increasing in number to meet the action threshold. When soybean reaches the R6 (full seed in one of the upper four nodes) growth stage the aphid density must be greater than 250 and plants be under stress to trigger an insecticide application. Once soybeans reach the R7 and R8 (maturity) growth stage, plants do not need to be sprayed. Since it takes a little while for aphid populations to increase and since most of our soybeans are already at the R4 or R5 growth stage we likely will not need to spray for aphids this season. However it is important to scout for aphids to ensure the soybeans do not need to be sprayed.

Aphids have been found in Minnesota and North Dakota that are resistant to pyrethroid insecticides, so wait until the action threshold is met and consider not applying a pyrethroid insecticide. There are other options.

WHY ARE CORN HUSKS
TURNING A TAN COLOR?

I was in a corn field this week that has ear mold already. The ear mold was diplodia. Only about 1% of the ears in the field were affected.

Diplodia is caused by the fungus Stenocarpella maydis. Increases in no-tillage, reduced tillage, planting continuous corn, growing susceptible hybrids, and having the right weather conditions all increase the likelihood of having diplodia ear rot.

You can recognize the disease starting from the outside of the ear. The husks will prematurely turn a tan to light brown color starting at the base and have moisture near the base of the ear and on the shank. When you open up the ear there will be a grayish-white or grayish-brown mold growing between and over the kernels of corn. The disease usually starts at the base of the ear and works its way to the tip of the ear, but can start in the middle of the ear. If the disease is severe enough it can consume the entire ear. Another identifying feature to look for as time progresses are black specks scattered on the husks, cob, and sides of kernels. These black spots are called pycnidia which are spore-producing structures of the fungus.

The pycnidia overwinter on corn debris and are a source of infection for the next year. Dry weather prior to silking followed by wet conditions at and just after silking favor the disease. The first 21 days after silking are the most vulnerable for the ear getting the disease.

Harvested grain infected with diplodia will be discounted at the elevator. Removing as many kernels as possible during harvest and prior to putting it in the bin will reduce the dockage. Increase fan speed on the combine. Cleaning the grain before storage will reduce the fine particles that will fill up air spaces and reduce air flow in the grain bin.

It is critical to dry the corn to 15% moisture to stop the growth of the fungus. Diplodia-damaged kernels stored above 15% will cause spoilage, damage, and self-heating. Dry grain to below 14% moisture and cool to below 50°F as quickly as possible if diplodia ear rot is significant. Store grain to below 30°F during the winter months and do not store the grain during summer months.

Stenocarpella maydis produces a toxin called diplodiatoxin. This toxin does not seem to cause health problems for livestock. However, animals will reduce their feed consumption if too much diplodia is present in the feed.

Management of the disease includes tillage and planting resistant hybrids. Tillage should bury as much of the corn residue as possible. Current research is inconsistent as to the effectiveness of fungicides to control the fungus.

SOUTHERN RUST OF CORN

Southern rust has been confirmed in the southern part of Ohio and may have been found in the Shelby Auglaize County area now. Southern rust does not over winter. It must be brought up from the southern United States with air currents.

Southern rust is characterized by the presence of small, circular, light orangish pustules predominately on the upper surface of the leaf. In comparison, common rust is characterized by larger, more elongated, and darker cinnamon-brown pustules on the upper and lower side of the leaf. Nearly every corn field has some common rust this season.

Start scouting now for Southern rust, especially late planted corn that has not tasseled. Once the Southern rust is present, it will quickly spread to other parts of the plant and to other plants. Best results when using fungicides has been when applications have been made at the appearance of a few pustules.

The later in development the corn plant, the less of a concern Southern rust will negatively impact yield. Some research shows plants need to be protected from Southern rust through the R4 (dough) stage of growth. If the Southern rust is present now in corn that has not tasseled, then a second fungicide application may be necessary. Several fungicides provide good to excellent control.

STINK BUGS

It is time to start scouting for stink bugs in soybean. Last year there ended up being more damage to soybean from stink bugs than thought. This was due to not enough scouting.

The way to tell an adult stink bug from other insects is the triangular structure called a scutellum that is found in the top middle section of the bug. The scutellum is not obvious in the nymph stage (growth phase), so look for a wide body with no wings and a thorax (area between head and abdomen that tapers toward the head from the rear of the thorax).

There are several species of stink bugs capable of injuring soybean. The green stink bug is the largest. The entire part of the bug is green in the adult stage. In the nymph stage the thorax, the part of the insect between the head and abdomen, is black and there are two black spots on the top side of its abdomen. The brown stink bug is the smallest, although within 2/3 the size of the green stink bug. The top side of a brown stink bug is brown and the bottom side is green. One that is very similar to the brown stink bug is the spined soldier bug. The spined soldier bug has sharper and a little larger point on its shoulders and has yellow-orange legs compared to the brown stink bug. The red-shouldered stink bug is green in color similar to the green stink bug, but is smaller and has a little larger point on its shoulder. There is a dark to faint red to pink colored line that goes across the shoulder or protonum of the red-shouldered stink bug. The brown marmorated stink bug is a newer stink bug species to our area. Identifying features for the adult include a speckled brown-grey color with a white band on its antennae and dark and white bands around the edges of the abdomen with the whitish marks forming a triangle.

Stink bugs have piercing sucking mouth parts so they pierce the soybean pod where there is a seed and remove the juices from the seed causing it to collapse and shrivel.

To scout for most stink bug use a sweep net. Move the sweep net back and forth 10 times while walking forward. Do this several times in the field. For brown marmorated stink bug walk a soybean very slow looking for them or stand still for a few minutes and thens look for them. If you find four or more nymphs and/or adult stink bugs per 10 sweeps, then it is time to spray. If growing seed beans the threshold is two bugs per 10 sweeps.

Most soybean insecticides will effectively control stink bugs.

SHOULD I APPLY FUNGICIDE TO SOYBEAN?

We have continued to receive large amounts of rainfall in the past week with below normal temperatures, although we are currently receiving above average temperatures. Soybeans are anywhere from first trifoliate for double crop soybeans to nearly beginning pod stage (R3 – 3/16 inch pod on one of upper four nodes with fully expanded leaf). The beginning (R3) to full (R4) pod stage is the recommended timing to apply fungicides to soybeandff.

Frogeye leaf spot, sclerotinia stem rot (white mold), and brown spot are the most common soybean foliar diseases in Ohio. At this time brown spot is the most prevalent foliar disease in the county with no frogeye leaf spot or sclerotinia stem rot seen yet. Frogeye leaf spot and white mold usually cause the greatest yield losses.

Spores of the fungus causing frogeye leaf spot are produced on last season’s residue and are dispersed long distances (from southern U.S.) by wind. Spore production and infection requires warm and humid weather conditions. The fungus causing sclerotinia stem rot begins growing when soils are shaded, moist and cool (40 to 60°F). Spores are produced and infection occurs when maximum daily temperatures are cool to moderately warm (< 85°F) and the presence of moisture from rain, fog, dew or high relative humidity. A dense soybean canopy helps to insure the proper conditions for infection. The brown spot pathogen spreads from the soil to young leaves by rain splash infecting the unifoliate and first trifoliate leaves in most cases. During warm wet weather the disease may move up the plant, although modern varieties reduce this upward spread.

Soybean yield improvement from applications of fungicides and fungicides plus insecticides have been variable. In five years’ worth of research, usually in the absence of disease and below insect threshold levels, soybean yield increased from 1.23 to 3.53 bushels per acre. This data was from 297 trials in Indiana, Illinois, Iowa and Nebraska. On average the fungicide plus insecticide treatment improved yields more frequently than fungicide alone, although this was not always the case.

If we use a current soybean price of $10.00 per bushel and the cost of a fungicide plus application of about $20.00 per acre and the cost of fungicide plus insecticide plus application of about $26.00 per acre, the breakeven yield for fungicide alone is two bushels per acre and 2.6 bushels per acre for fungicide plus insecticide. On average soybean yields were above the breakeven point only 42% of the time.

At this time, Dr. Anne Dorrance is not recommending the application of a fungicide, unless the soybean variety is moderately to highly susceptible to frogeye leaf spot and the disease is already present. In summary, better returns from a fungicide plus insecticide treatment will occur if disease and insect pressure are present and the variety is susceptible to the disease. Not all fungicides are equal in their ability to control diseases, so be sure to use a fungicide that will control the most diseases most effectively.

If you apply a fungicide or fungicide plus insecticide leave an untreated strip to see if there was a benefit to applying these products.

WHY ARE THERE HOLES IN MY CORN LEAVES?

Now that Dannon wants non-GMO milk for some of their products, many farmers planted non-GMO corn this season to feed the cows. In addition there is a premium for non-GMO corn which inticed additional farmers. One of the traits not in this non-GMO corn is the production of the Bt toxin that controls caterpillars such as the European corn borer. The European corn borer was one of the most troublesome corn pests prior to the introduction of the Bt GMO event. Since the introduction of Bt corn, European corn borer populations have plummeted, but have not totally disappeared. Therefore there is great concern that European corn borer is attacking the non-GMO corn and may increase the overall population of European corn borer over time.

European corn borer feeding is being reported in parts of the state at this time. Therefore scout fields now for the presence of European corn borer damage. The most obvious visual sign of feeding is the presence of “shot holes” through multiple leaves in the whorl of the plant. The shot holes will be in a line at the same level in two or three leaves. There may also be short linear holes in the leaves. Some European corn borer will bore into the midrib of the leaf causing it to break off.

Larvae are most likely to be found in the earliest planted corn. The larvae are cream colored with rows of black dots and a black head. You will usually find them in the whorl. You will need to peel back or pull the whorl to find the larvae. You are looking for larvae that are less than ½ inch in length. At this stage and earlier the larvae are most susceptible to an insecticide. This is because once larvae get beyond the ½ inch size they start to bore into the stalk. Once a larvae is inside the stem insecticides are no longer effective.

Larvae will feed in the stalk and potentially cause the plant to fall over. The larvae that are present at this time is part of the first generation of the European corn borer. The larvae typically bore into the stem below the ear leaf. Once the larvae reach full size they will pupate. Adult moths will emerge from the stems in late July to early August starting the second generation. The moths mate in grassy areas such as roadsides, waterways, and weed patches. The female lays eggs on the underside of the leaves. Eggs are laid in groups of 15 to 30 with the eggs overlapping each other looking like fish scales.

The hatched larvae will move to leaf axils and sheaths feeding on pollen and plant tissue. It is at this point in time when insecticide applications will need to be made again. The second generation borers normally attack in the ear zone of the plant, although they can be found near the top of the plant as well. The borers will bore into the stalk, the ear shank, or the ear. Once inside insecticides will no longer be effective. The greatest damage at this time is where larvae bore into the ear shank and cause it to fall off the plant prematurely or later near harvest. If larvae bore into the ear, ear molds may become a problem.

When scouting for the first generation larvae inspect 20 consecutive plants in each of 5 areas of the field. Determine the percentage of plants having feeding damage. Once the number of plants having feeding damage reaches 75 to 80%, then it is time to apply an insecticide. Effective insecticides include Ambush, Asana XL, Bacillus thuringiensis, Baythroid XL, Belt 4SC, Besiege, Brigade, Cobalt Advanced, Coragen 1.67SC, Declare 1.25CS, Delta Gold 1.5 EC, Fanfare EC and ES, Fastac EC and SC, Hero, Intrepid 2F, Lannate LV and SP, Lorsban 15G, Mustang, Mustang Maxx, Paradigm, Prevathon, Seven XLR Plus, Silencer, Stallion, Tracer, Vulcan, and Warrior II.

Scouting for the second generation is more difficult than for first generation. Knowing when moth flight is occurring is important. One way to notice this is when driving after dusk moths start to hit the windshield. At this time start scouting for egg masses in late planted corn or in fields with high first generation larvae. Look for the egg masses on the underside of leaves which are located two leaves below the ear leaf and two leaves above the ear leaf. Inspect 20 plants in each of 5 areas and record the number of egg masses and or larvae found on plants. Determine the average number of egg masses per plant for the field and/or the average number of larvae per plant. Economic threshold should be determined through a formula considering number of larvae/eggs, yield loss, and cost of insecticide and application. The formula can be found at the following web address:  https://extension.entm.purdue.edu/fieldcropsipm/insects/euro-cornborer.php

CORN CUTWORMS

Moth counts for cutwork are running high in areas of the state that are doing moth counts. I had heard of minor cutworm damage a couple of weeks ago in Darke County.

There are twelve different species of cutworm. The black cutworm, dingy, and variegated cutworm are most common in our area. Black cutworm are light grey to nearly black in color, greasy appearance, have two black stripes on its head, a pale band along the top of the body, and two sets of paired unequal spots on the side. The dingy cutworm are pale gray to reddish brown with mottled pigmentation and light grey, V-shaped markings on its back, and there are two sets of a pair of spots that are of equal size on the side. The variegated cutworm has a narrow line of pale yellow dots along the middle of its back and varies in color. Larvae can reach up to two inches in length.

Black cutworms over winter in the southern United States and the moths must travel north. The dingy cutworm over winters in the pupa stage in Ohio. Larvae hatch in two days to two weeks depending upon the species.

Corn fields at most risk include poorly drained and low lying areas, natural vegetation nearby, late tillage, reduced tillage, weeds prior to planting, cover crops, especially cereal rye, late-planted corn, and corn planted after soybean.

Scout fields closely to see if cutworms are present in corn fields. Cutworm larvae live underground during the day and come out at night to feed. Scout fields in the early morning or at dusk by looking for leaf-feeding, cutting, wilting, and missing plants. Check 20 plants in five different areas of the field. When injured plants are found, dig around the base of the plant looking for live cutworms. Look carefully beneath clods, the planter furrow, or in soil cracks. Scouting at night is another option, but excellent lighting is required. Irregular holes in leaves are a sign of young cutworms. Cut plants do not occur until the larvae have reached the fourth instar.

A rescue treatment is recommended when 3% or more of the plants have been cut or tunneled, corn plants are in the 2nd to 6th leaf stage, and larvae are still one inch or less. Insecticides with activity include permethrin, chlorpyrifos, zeta-cypermethrin, lamda-cyhalothrin, cyfluthrin, and zeta-cypermethrin plus befenthrin.

MANAGING WATERHEMP IN CORN

Planting has begun in the county. Now it is time to focus on managing weeds in corn. One of the most troublesome weeds in corn is waterhemp. Waterhemp is related to the pigweeds and looks very similar to them.

Choosing the right herbicide based upon the weeds in a field is very important to maximizing weed control! Last year I observed 32% of soybean fields in Auglaize County having waterhemp at harvest time. This is very alarming! The waterhemp germinates late into the season similar to giant ragweed, making perfect control difficult. Also, the waterhemp is likely resistant to glyphosate and ALS (group 2) herbicides and in some populations resistance to PPO inhibiting (Group 14) herbicides. There is a possibility the waterhemp is resistant to atrazine as well, but this has not been confirmed in Ohio at this time.

The most effective strategy to controlling waterhemp in corn is to apply the full rate of an effective preemergence or soil-applied herbicide followed by postemergence herbicide(s) having residual control mixed with glyphosate. This strategy should only be necessary in fields having moderate to high densities of waterhemp or to ensure low and moderate density populations do not increase. It is difficult to make a total postemergence herbicide program work in corn because the herbicides will need to be applied too early into the season. This strategy may work in a low density population, but there is no guarantee. For no or low density waterhemp populations, the application of three quarters rate of an effective preemergence product followed by a late postemergence product having residual control could be effective.

The most effective preemergence herbicide(s) include: Acetochlor plus atrazine (rates containing at least 1.5 pounds active ingredient of atrazine); Acuron; Lumax; Lexar EZ; and Verdict plus acetochlor. Postemergence products to be mixed with glyphosate containing the longest residual control include: Callisto Xtra; Atrazine at the highest remaining rate following a preemergence application of atrazine; or an effective postemergence herbicide mixed with atrazine at the highest remaining rate following a preemergence application of atrazine. Glyphosate mixed with Solstice is the most effective postemergence herbicide applied late in corn having some residual control. The next most effective postemergence herbicides mixed with glyphosate providing some residual control and applied late include: Callisto; Callisto GT (Roundup Ready corn only); Capreno; Halex GT (Roundup Ready corn only); Impact; Laudis; Realm Q; and Revulin Q. Status mixed with glyphosate will control waterhemp as good, but has no or very little residual control. Glufosinate plus atrazine applied to LibertyLink corn can be effective, but it must be applied to small waterhemp and following a full rate of the most effective preemergence herbicide.

Use the maximum rate of postemergence herbicides. For postemergence treatments be sure to include the most effective adjuvant for the non-glyphosate products. Read and follow label directions, especially as it relates to the maximum size of corn for postemergence products. Glyphosate can only be applied to Roundup Ready corn.

WHAT IS COMMON LAMBSQUARTERS?

Common lambsquarters is a broadleaf or dicot herbaceous (not woody) weedy plant.  Common lambsquarters is a member of the Amaranthaceae or pigweed family.  There are several lambsquarters species which look very similar to each other, so I usually just call the most similar species lambsquarters.  There is a lot of genetic diversity in common lambsquarters making it difficult to identify from other species.

It can be identified by its linear cotyledons with the first node of true leaves usually being opposite with most subsequent leaves being alternate.  Leaves are simple, triangular to lanceolate in shape usually having a toothed margin and having a white mealy upper leaf surface of the youngest leaves of the plant.  Stems are grooved and purple to pinkish in color at the base of the plant.  Flowers are small and greenish with no petals and arranged in spikes at the end of stems.  Plant height varies from 10 inches to up to 9 feet with most plants getting about four to five feet tall.  The seeds are a dull black color mostly round in shape, but having a slight notch or hook on one side.

Lambsquarters is a summer annual plant meaning it must emerge from a new seed every year.  It is one of the earliest species to emerge in the spring beginning in April.  It can continue to emerge into August when soil is disturbed.  A single lambsquarters plant may produce up to 500,000 seeds with most producing 75,000 seeds that remain viable in the soil for greater than 40 years!

Lambsquarters is difficult to control in soybean and occasionally difficult in corn.  Lambsquarters can be a weed problem in wheat, although not usually.  The wheat usually keeps it suppressed, but will grow readily after wheat harvest.  Lambsquarters is a common weed of newly seeded alfalfa, especially spring seedings.

The most successful strategy to controlling lambsquarters in soybean is to apply preemergence residual herbicides.  The most effective herbicides include products containing sulfentrazone (Spartan), flumioxazin (Valor), chlorimuron (Classic), cloransulam (FirstRate), metribuzin, imazethapyr (Pursuit), flumetsulam (Python), and imazaquin (Scepter).  Premixtures containing two or more of these products are more consistently effective compared to a single product.  In no-tillage soybean production apply 2,4-D ester with glyphosate seven days before planting to provide the most effective control. In Roundup Ready soybeans apply glyphosate at 1.5 pounds acid equivalent and include a non-ionic surfactant at 0.25% v/v and amonium sulfate at 7.5 pounds per 100 gallon of spray mixture as lambsquarters can be difficult to control.  In non-Roundup Ready soybean apply Harmony and Resource, Cadet, or Marvel to small lambsquarters.  In Liberty-Link soybean apply glufosinate (Liberty) to small plants.

In corn apply preemergence herbicides containing atrazine, Balance Flex, mesotrione (Callisto), flumioxazin (Valor), flumetsulam (Python), or Sharpen.  Herbicide products containing more than one active ingredient are more effective.  In Roundup Ready corn apply glyphosate at 1.125 pounds acid equivalent per acre and add non-ionic surfactant at 0.25% v/v and ammonium sulfate at 7.5 pounds acid equivalent per acre.  Tank mixing Status, mesotrione plus atrazine, Impact plus atrazine, or Laudis plus atrazine will improve control and provide some residual control.

In alfalfa apply bromoxynil (Butctil) to four trifoliate alfalfa, 2,4DB to two trifoliate alfalfa, Raptor to two trifoliate alfalfa, or glyphosate in Roundup Ready alfalfa having two trifoliates.

PREPARING YOUR PLANTER FOR SPRING

We are only about 60 days (hopefully less) from planting our next corn crop.  Beginning to prepare your planter for spring is a wise choice.  With lower than desired commodity prices, fine tuning the planter provides an opportunity to improve yields this season.  Corn yields can be reduced by 2.5 bushels per acre for every one inch of spacing difference from the average plant spacing.  The more evenly spaced the seeds and the more uniform the emergence the greater the corn yield.  You only get one chance to plant a corn crop each spring to maximize yields.

The following is a list of things to work on now before planting:
1)  Check double disk openers.  The disks should be no less than 14.5" in diameter.  There should be 2 to 2.5" of contact with the two blades.  To check the contact distance use a business card that is normal thickness.  Insert the card between the two blades and slide it from the top down along the front of the disks until the card won't lower any further.  Mark that spot with chalk.  Next, take the card from the back and slide it forward until it stops and mark that spot.  Measure the distance between the two marks, if less than 2 inches, reshim the blades or replace the blades.  Check the bearings on the disk openers.  If the blades wobble while turning, replace the bearing.  Check blades for cracks and that the bearing housing are correctly riveted.
2)  Calibrate corn meters as this may increase yields by six bushels.  Several companies offer this service.  Use it.  The most accurate calibration is when you take along seed samples of the hybrids being planted.
3)  Check seed tubes.  Be sure there are no obstructions in the tube and that it is smooth, especially at the opening of the tube.  The tube can become worn by the disk openers or damaged by objects during planting.  Be sure the seed tube is installed securely.  Clean seed tubes and sensors.
4)  Adjust closing wheels to ensure equal distance from the center of the seed trench. To determine this alignment lower the planter onto concrete and move the planter ahead.  Then observe if the disk markings on the concrete line up with the closing wheels.  Be sure there is no side to side movement of the wheels.
5)  Check depth gauge wheels.  Replace bearings if the wheel wobbles at all.  Wheels must maintain slight contact with the disk openers at all times.  Check the contact by holding the gauge wheel up in planting position and rotating the wheel.  Rear bushings and depth control arms need to be in good shape to insure they can be properly adjusted to maintain correct contact with the disks.
6)  Check parallel linkage.  Worn bushings increase row bounce which increases seed bounce.  Stand behind the row unit and wiggle it up and down and back and forth checking to make sure bushings are tight.
7)  Check for excessive seed box movement. Excessive motion will cause seed meters to improperly drop seed into the seed tube.
8)  Adjust no-till coulters to run 1/4" higher than the seed opening disks.  Do this by placing planter in the down position on a level flat surface.
9)  Check all chains and drive sprockets.  Replace worn chains and lubricate them.
10) Drive shafts and bearings need to be properly lined up to insure smooth operation.
11) Check planters with finger pick-ups for wear on the back plate and brush.  Use a feeler gauge to check tension on the fingers, then tighten them correctly.
12) Lubricate all grease fittings.
13) Check the frame for any cracks or bends.
14) Check all wiring harnesses for any broken wires.

Remember safety while working with the planter.  Any part of the planter that came in contact with the treated seed is contaminated with the pesticides applied to the seeds.  Wear chemical resistant gloves when working on these parts.  In addition, use gloves to keep grease and oil from your hands.

USING CORN TO MANAGE WEEDS

Only 18% of soybean fields were weed-free this fall in Auglaize County.  Weeds left to produce seeds at the end of the season will increase weed densities in future growing seasons, making weed control more difficult.  Surviving resistant weeds make weed control even more difficult.  The most problematic agronomic weeds produce at least 1000 seeds per plant, but can produce over one million seeds per plant.  On average a single waterhemp plant likely produces 100,000 seeds per plant, but will commonly produce up to a half million seeds.

There are more herbicides and herbicide sites of action available for controlling weeds in corn compared to soybean.  That is why weed control is usually better in corn.  Corn herbicides are also more effective than soybean herbicides.  Take advantage of the many effective corn herbicides and strive to achieve 100% weed control in corn to provide more effective weed control in soybean by reducing weed densities.  Despite the numerous effective herbicide programs available in corn, wise choices are still required.

There will be no new active ingredients for corn in 2017, unless Elevore from Dow AgroSciences gets labeled before the growing season.  Elevore herbicide will have a new growth regulator active ingredient that will effectively control marestail in burndown applications.  Currently, there is only one new corn herbicide for next season, Acuron Flexi.  Acuron Flexi is Acuron (mesotrione, S-metolachlor, bicyclopyrone, and atrazine) without the atrazine.  Resicore, a mixture of acteochlor, clopyarlid, and mesotrione was labeled just before planting last season.  Both products can be applied preemergence or early postemergence.

The most broad-spectrum residual corn herbicides include:  Acuron plus atrazine, Lexar, Lumax, Cinch ATZ plus Instigate, Resicore plus atrazine, Corvus plus atrazine, Balance Flex plus any atrazine premix (atrazine plus acetochlor or metolachlor), and SureStart plus atrazine.  These products will provide the longest most effective control of key broadleaf weeds in corn, including giant ragweed.  In conventional tillage these herbicides may provide season long control.  Other residual herbicides are available, but control is less requiring a more effective postemergence herbicide program.  Despite the effectiveness of these broad-spectrum herbicides, scout fields to determine if a postemergence herbicide application is necessary.  Grasses, giant ragweed and waterhemp are the most likely species requiring a postemergence application.

For no-tillage corn a combination of 2,4-D ester and glyphosate will need to be mixed with the residual herbicides prior to planting to control existing vegetation, especially if cover crops are present.

If Roundup Ready corn is planted and if grasses are present, a postemergence glyphosate application at 1.125 pounds acid equivalent per acre will effectively control grasses.  If giant ragweed and waterhemp are present and they are resistant to glyphosate and ALS-inhibiting herbicides, then other herbicides will need to be added with glyphosate.  Callisto Xtra, dicamba plus atrazine, Impact or Armezon plus atrazine, and Laudis plus atrazine most effectively controls waterhemp and giant ragweed.  These postemergence herbicides will need to be applied before 12-inch corn due to the atrazine restriction.  This early application timing may require the addition of metolachlor or acetochlor to control late season waterhemp.

Utilize corn and wheat to manage troublesome weeds, such as giant ragweed and waterhemp.

WILL STRIPE RUST RETURN IN 2017?

Stripe rust was a fairly common disease of wheat last season.  It has rarely been a problem in the past.  Why was it so bad last year?  One reason is that it is believed to have overwintered last season, something it usually does not do because it must have a living host to stay alive.  Only wheat and barberry can host this rust species.  Other reasons for the 2016 outbreak include susceptible wheat varieties, ideal growing conditions, and the possibility of the pathogen adapting to warmer temperatures.

Wheat stripe rust is caused by the fungus Puccinia striiformis f.sp. tritici.  There are a total of 109 races or varieties of this pathogen making plant host resistance difficult to work all of the time.  Wheat stripe rust has small yellowing-orange spores that are arranged in lines on wheat leaves.

In most years the spores must blow in from the south where the fungus overwinters every year.  Once the spores arrive, they need proper moisture, temperature, and a susceptible wheat variety for infection to occur.  Disease development occurs during cool (50 to 64 degrees F) wet (rain and dew) conditions.  Spores can survive from 32 to 77 degrees F.

Two biological features of the pathogen makes proper timing of fungicide applications difficult.  First there is a latency period of 11 to 14 days, meaning visible signs of the pathogen do not show up for 11 to 14 days.  Secondly the life cycle is very short (7 days) meaning many spores can be produced in a short amount of time.

Strategies to control this disease include host plant resistance, controlling volunteer wheat to reservoirs of the disease, and fungicide applications.  Based upon Michigan State University data only eight wheat varieties were placed in their wheat variety trials having resistance to stripe rust.  Visit the following website to know if your wheat variety has stripe rust resistance: http://msue.anr.msu.edu/news/new_ratings_of_wheat_varieties_for_stripe_rust

Strobilurin fungicides (Headline, Quadris, others) can effectively control stripe rust, but must be applied before infection and before heading of wheat (to reduce head scab flare up).  If stripe rust is already present, then the use of a triazole class of fungicide (propiconazole and others) is the most effective.  The problem becomes when do I apply the fungicide for control or the stripe rust versus a fungicide application for head scab.  Only Prosaro and Caramba are the most effective at controlling head scab and they can only be applied once during the season, so proper timing of these fungicides for head scab is the goal, but is usually too late to control the stripe rust.  Therefore other effective triazole fungicides need to be applied after presence of the disease and before flowering.  Apply a fungicide when a few pustules are observed on leaves below the flag leaf.

I have not heard of any stripe rust this fall, so hopefully we will not have a problem in 2017, but scout fields carefully in the spring for the presence of the disease.

CORN ROOTWORM AND MANAGEMENT

Corn rootworm is a beetle that causes damage to corn.  There are two species that are present in our area, western corn rootworm and northern corn rootworm.  The western corn rootworm is more prevalent than the northern corn rootworm.  The western corn rootworm adult is gold in color with a black head and three black stripes on the wing covers.  These stripes blend together to the point of the lines being hard to distinguish on male adults.  The adult northern corn rootworm is pale to dark green in color and is much smaller than the western corn rootworm.

In late summer the adult female beetles lay eggs in the soil.  These eggs survive the winter months.  The eggs hatch from late May to mid-June when corn is about in the four-leaf stage.  Egg hatching usually coincides with the appearance of adult firefly (lightning bug) beetles.  The eggs hatch into larvae that feed on corn roots for three to four weeks.  A mature larva is about 1/2 inch long having a dark brown head and plate (rear end of larvae).  The larvae pupate for about one to two weeks before emerging as adults.  The adult beetles feed on corn leaves, pollen and silks.  The adults are active for about 10 weeks.

Corn yield loss can be substantial whether it is from root feeding or silk clipping and is worst when root and silk feeding occurs.  Root feeding by the larvae can be so severe that corn lodges and yield loss is greatly reduced because just a few roots support the plant.  Root feeding is most severe in moderate to dry years because roots do not have enough moisture to regenerate rapidly.  If soils are saturated for multiple days when the larvae hatch they can be killed, greatly reducing and sometimes eliminating root feeding.  Some silk clipping can occur causing minimal to no yield loss; however, silk clipping can be severe enough to drastically reduce pollination thereby reduce corn yield.

The most effective strategy to managing corn rootworm is to rotate to crops other than corn, since larvae only feed on corn roots.  This strategy is not always full proof as it is possible for a variant of the western corn rootworm adult to lay eggs in soybean fields that if rotated to corn the following year can injure corn.  The presence of the western corn rootworm variant laying eggs in soybean is greatly reduced compared to the early 2000's.  Another strategy is to apply a soil-insecticide at planting that effectively controls the larvae when they hatch.  The third strategy is to plant a corn hybrid that produces a Bt toxin that controls the rootworm larvae.  This strategy is not full proof as the original trait did not produce enough toxin to completely control the rootworm, allowing for the build-up of Bt resistant western corn rootworms.  If planting Bt hybrids, plant hybrids expressing the greatest toxin levels and that contain multiple genes for corn rootworm.  Corn rootworm populations are currently very low in the area and just simply planting corn after soybean is the only control strategy necessary.

WHAT IS A NUTRIENT MANAGEMENT
PLAN AND DO I NEED ONE?

A nutrient management plan (NMP) is a tool growers can use to improve the efficiency of all types of nutrients applied to crops while increasing profit and reducing environmental and production risks.  They were first used to manage manure on concentrated animal feeding operations.  Today all farmers are encouraged to develop a nutrient management plan.  There are ten major components to a nutrient management plan, which include the following:  field maps, soil test, crop sequence (rotation), estimated yield, sources and forms of nutrients, sensitive areas, recommended rates, recommended methods, and annual review and updates.  These are necessary to make the most economical and environmental nutrient recommendations.

A nutrient management plan can take several forms, including those originating from the OSU Nutrient Management Workbook, the Comprehensive Nutrient Management Plan (CNMP) that meets all of the requirements of NRCS, or a plan equivalent to these that is approved by the Director of the Ohio Department of Agriculture or his designee and contains a minimum of information such as current soil tests, following the 4R's for all nutrients, fields covered by the plan, crops grown, and yield information.

Plans provide both fertility recommendations and an environmental site risk for individual fields that help identify resource concerns impacting nutrient and sediment loss.

The two biggest reasons for completing a nutrient management plan is to serve as a basis for "affirmative defense" and to potentially obtain funding from NRCS/FSA for certain programs such as EQIP.  Affirmative defense allows protection against private civil lawsuits for persons owning a farm that follows best management practices such as a nutrient management plan.  Other reasons for preparing a nutrient management plan include potential to reduce fertilizer costs, potential to increase yields, maximize nutrient use of efficiency and minimize nutrients leaving the field thereby potentially improving water quality.

Ohio State University Extension has received a grant from the National Fish and Wildlife Foundation to hire four individuals training to prepare nutrient management plans for commercial fertilizer and comprehensive nutrient management plans for manure applications at no cost.  Other contributors to the project include the Ohio Farm Bureau Federation, Ohio Soybean Council, Ohio Small Grains Marketing Program, and Ohio Corn Marketing Program.  These four individuals are writing comprehensive nutrient management plans for growers in the Western Lake Erie Basin.  These individuals will be in Auglaize County sometime in February or March to collect information from interested farmers to prepare comprehensive nutrient management plans.  If you are interested in completing a nutrient management plan soon, contact Tony Campbell at 419-399-8225 or wait until dates have been established when the writers will be in Auglaize County.  Tony is the closest of the four individuals to Auglaize County.  If Tony is unavailable feel free to contact the Auglaize County Extension Office at 419-739-6580 and I can get you additional information.

STORING CORN

Now that corn harvest is completed it is time to manage the corn in the bin.  Use integrated pest management practices to protect the corn from mold and insect activity.  This will be extremely important this year due to the Gibberella, Tricoderma, Fusarium, and Diplodia ear rots.  At this time all that can be done to manage the corn is to control temperature of the corn, manage the depth of the grain in the bin to allow for good airflow, and to monitor moisture, mold and insect populations.  Proper management of the grain can prevent the use of insecticides to control insects.

Corn moisture should be held at 15%.  Problems with storage can occur when corn has been under-dried or not dried uniformly enough and high levels of trash and fine material are present.  Therefore, it is important to check the top layer in all bins about one week after drying and cooling to make sure no moisture build up has occurred.  Elevated temperatures and/or moisture can cause mold and insect growth even in cool weather.  The growth of mold and insects will produce heat causing further deterioration of the grain.

Controlling temperature and moisture is the most cost-effective way to prevent spoilage problems.  The temperature of the corn should match the average air temperature.  It is better to have the grain cooler than warmer.  Mold and insect activity is held in check when grain temperatures are below 55 degrees F and relative humidity is below 65%.  To keep the molds from growing and producing mycotoxins the grain should be stored at 36 to 44 degrees F.  Clean corn dried to 15% should store for at least 6 months if cooled properly.

Even properly dried corn can spoil if corn is not cooled thoroughly.  Uneven grain temperatures can lead to moisture migration to the top center of the bin, promoting mold and insect growth.  Moisture migration can be prevented when grain temperature is equalized throughout the bin with aeration.  Aeration time to remove the moisture depends upon the size of the fan relative to the amount of grain.

If possible, remove the top cone of corn occupying the upper portion of the bin.  Removing the corn will reduce the risk of spoilage as most storage problems occur in the upper center of the corn pile due to air traveling through the path of least resistance (lowest corn pile). Removing the top cone will also remove fines leading to better air flow.

Stored grain should be inspected in the fall and spring every one to two weeks and every two to four weeks during the winter.  This is much more critical this year due to the amount of molds already present on the corn.  Please consider all safety procedures before entering the bin, especially if grain has been removed.

WEEDS IN WHEAT

The wheat crop is looking good so far.  Last year there were many wheat fields that had winter annual grasses in the wheat at harvest.  In addition this fall, winter annual broadleaf weeds were present in soybean fields prior to wheat seeding.

Weeds can be thick enough in the fall to compete against the wheat by reducing growth and tiller production.  The most common winter annual broadleaf weeds include common chickweed, purple deadnettle, henbit, shepherd's-purse, and field pennycress. Two other winter annual weeds of concern are marestail and cressleaf groundsel.  Controlling marestail in the fall may reduce the need to control them after wheat harvest, but spring emerging marestail will not be controlled.  Cressleaf groundsel is poisonous to livestock and was fairly common in wheat fields last year.  Drying the cressleaf groundsel does not reduce toxicity, so plants in the straw used for bedding could become a hazard to livestock. Common winter annual grasses that can contaminate harvested wheat include downy brome and cheat.  There was a field last year where the wheat yield was probably reduced due to the density of cheat.

Common chickweed, purple deadnettle, and henbit can be identified now by their opposite leaves and upright or prostrate stems.  Purple deadnettle and henbit have a square stem.  Shepherd's-purse, field pennycress, marestail, and cressleaf groundsel all have rosettes (circular pattern of leaves close to the soil).  Shepherd's-purse and marestail have hair on the leaves while field pennycress and cressleaf groundsel do not.  The cressleaf groundsel has rounded lobes on the leaf and can have a blue-green-purple leaf color.  Downy brome will have hair on the leaves and sheath.  Cheat has less hair.  Both will have a twist to the leaves.

Fall application of Olympus or PowerFlex will provide more effective control of cheat and downy brome compared to a spring application.  Fall application is the best way to greatly reduce or eliminate winter annual broadleaf weed seed production early in the spring, although spring applications can control plants in the spring.  The problem with applying herbicides in the fall is that summer annual weeds may need to be controlled in the spring, adding an extra herbicide application.

Olympus will more effectively control the common winter annual broadleaf weeds compared to PowerFlex.  It is unknown as to how effective these two herbicides will be in controlling cressleaf groundsel, but I assume Olympus will be better because it is more effective on marestail.  Olympus and PowerFlex will not control ALS-resistant marestail since they are Group 2 herbicides.  This is noteworthy because most marestail populations have a significant density of ALS-resistant plants.

Olympus can be applied to any size of wheat.  Wheat must have at least three leaves to apply PowerFlex.  No crop can be planted until 4 months after an Olympus application and a successful bioassay.  Soybean can't be planted until April 30th following a fall application of PowerFlex.

Scouting for and applying herbicides is most important for the cheat and downy brome.

NEW PEST PROBLEM FOR
FIELDS HAVING COVER CROPS

At the Cover Crop Field Day on Monday, it was reported that voles are becoming a problem in no-tillage fields having cover crops.  This is a localized problem at this time, but is occurring in several parts of the state, especially in northwest Ohio.

What is a vole?  A vole is kind of a cross between a mole and a mouse.  Voles have short tails, a short nose, and short legs.  Their body is wider or stockier compared to a mouse and mature voles can reach up to five to seven inches long.  The under fur is dense and covered with thicker, longer guard hairs.  Their tales have fur compared to a mouse.  They have small black eyes and small ears having fur.

Voles breed throughout the year having one to five litters and three to eight young per litter.  Their gestation cycle is 21 days.  Females mature in 35 to 40 days.  Therefore, large populations can increase very quickly.  However, voles have a short lifespan of two to 16 months due to the numerous predators feeding on them.  Populations tend to peak every two to three years and are most frequent during the summer and fall.  There are several different species of voles.

Voles consume a wide variety of foods.  They eat seeds, tubers, bulbs, rhizomes, leaves, and small plants, especially the cotyledons of soybean.  Voles can completely wipe out a stand of corn or soybeans.  They usually only eat germinating seeds and small seedlings up to 21 to 28 days after planting.  Voles are active day and night, year-round, with peak activity occurring at dawn and dusk.  Their home range can be up to a quarter of an acre.

Voles dig underground tunnels having numerous entrances and surface runways.  They pull the soil out of their burrows and scatter the soil or make small mounds away from the burrow.  They do not push the soil up or make mounds of soil like moles.  They make nests on the soil surface in cavities out of dried grass, which includes cover crop grasses, or under objects such as boards.  They also make nests below the soil surface.  Their runs on the soil surface are visible throughout the year, but especially after the snow melts since they do not hibernate.  The runs often have grass clippings on the soil surface.  Voles must have at least three inches of cover, preferably taller and dense canopies.

Scout fields and field borders for the presence of voles at least 30 days before planting. Look for active vole colonies and runways.  Voles prefer soils with good drainage and aeration, so scout there first.  Look for grass that is taller and greener because of the fertilizer effect from their urine and feces.  An active colony usually has fresh grass clippings near the entrance of the burrow.  If five active colonies per acre are found, then control measures should be implemented.

HARVEST SAFETY

Harvest season is one of the most dangerous times of the year around the farm.  Many activities are happening such as combine operation, transporting grain, filling grain bins, tilling soil, and hauling manure. Because there is a limited window to getting all of these things accomplished, long hours of work happen for much of this time.  When fatigue sets in, accidents are more likely to occur.

There are many moving parts on a combine, creating many hazards.  When leaving the combine seat, shut off the combine so nothing starts up unexpectedly.  Be careful working around the cutter bar.  Blow plant residue away from the combine engine as often as possible, especially if the engine is enclosed.

Be sure all lights are working properly on wagons and semi-tractors and trailers.  This is important for preventing accidents with other individuals.  It is important that other drivers know where we are and when we may be turning.  Wagons are to have a minimum of a slow moving vehicle sign, yellow flashing lights, and two types of reflective stickers.  It is also recommended to have solid red lights.

Carefully climb grain bins and do not enter a bin when the grain is being removed.

Cutting corners is usually when accidents happen, so please think ahead and be safe this harvest season.

SEEDING COVER CROPS

Cover crops improve soil health, reduce soil erosion, build soil organic matter, hold nutrients in the soil, increase resilience against soil compaction, provide some weed control, and produce extra forage for fall or next spring.  Planting multiple species and maximizing growth before the winter are two important goals at this time of the season.  However, all species need some minimum time to get established before a killing freeze to maximize the benefits of planting a cover crop.  We are now past the time to seed all broadleaf cover crop species as Austrian pea, radish, and rape are the fastest to grow and require a minimum of four weeks prior to a killing freeze.  This leaves winter rye, wheat, and barley or triticale as the only cover crops that should be seeded at this time of the year.  It is even too late to seed annual ryegrass.

Plant the cover crops as soon as possible to maximize growth.  Planting cover crops beyond November first is not desirable as there will not be enough fall growth thus causing more plants to die during the winter.  Plant the cover crop as deep as possible up to 1.5 inches.  Planting on the surface at this time of the year is not desirable as there will not be enough time for proper root development to survive the winter.

Drill these cover crops at 50 to 90 pounds per acre.  If planting corn next year, it is best to reduce the seeding rate for winter rye to 20 to 30 pounds per acre to reduce the allelopathic effects to the corn.

All of these species can be harvested for forage next spring.  Winter rye will yield the greatest, but wheat will have the greatest nutritional value.  All of these species will need to be killed next spring prior to planting so keep that in mind.

FALL HERBICIDE APPLICATIONS

Purple deadnettle, henbit, common chickweed, marestail (horseweed), field pennycress, shepherd's-purse, and cressleaf groundsel are already present in fields.  I have seen purple deadnettle and common chickweed up to 3 inches tall and marestail and field pennycress rosettes up to four inches in diameter!

The only way to try to eliminate seed production of these winter annual species before planting next spring is to apply herbicides this fall.  If marestail is not controlled this fall, it becomes very difficult to control next spring and requires at least four active ingredients to obtain good control.  One other weed that is important to control this fall is cressleaf groundsel, the yellow flowering weed in the spring.  If planting is delayed this plant will produce seed and blow downwind for distances similar to marestail.  There is so much of this weed around that it is becoming prevalent in hay and pastures.  This weed is poisonous to livestock when it is fresh and when it is dried, making it a serious problem for livestock producers.

Winter annual weeds can start emerging the first of August and continue to emerge until soil stays frozen for most of the day.  With each rain event in the fall, new emergence is likely.  I have seen new seedlings after the rain last week. This wide window of emergence can make control more difficult; however, controlling these weeds currently present at the end of October is most important than not spraying at all as these plants will be the largest, produce the most seeds, and be the most difficult to control next spring.  Plants emerging the closest to soil freezing are more likely to be controlled by freezing temperatures than large plants.

When should I apply the fall herbicides?  The window of application is quite wide, but must be done before soils freeze for most of the day (termperatures in the low teens for several hours) or become saturated with water making it difficult to spray.  Therefore, fall herbicides can be applied any time after mid-October and in many cases into December.  If applying herbicides in October a residual herbicide can control those plants emerging after the application.  It is always best to spray in as warm and sunny conditions as possible, although it is better to spray in cool conditions than not spray at all.  The cold weather will take herbicides longer to control plants and control may not be perfect, but some control is better than nothing. The injured plants will be more easily controlled next spring.

What should I spray?  A mixture of at least two herbicides is necessary.  The most cost effective herbicide combination should be the applied.  One program is to apply glyphosate at 0.75 pounds acid equivalent per acre (22 fluid ounces of Roundup) plus 2,4-D ester at 1.5 pints per acre (of a 4 pound active ingredient formulation).  The earlier this treatment is applied the more likely new emergence after the application will occur.  Another popular combination is a premixture of 2,4-D and dicamba, such as Brash applied at 1 qt/A plus metribuzin at 6 ounces per acre.  This program is fairly effective, but can be reduced under cold weather conditions because 2,4-D amine in these products is less effective under cold weather.  The metribuzin does provide some residual control for the fall (not the spring) allowing this treatment to be applied earlier.  These two programs allow any crop to be planted next spring while most other combinations available lock you into a specific crop next season.  If residual products are applied in the fall, residual herbicides will still need to be applied next spring to control summer annual weeds.

IT IS TIME TO PLANT WHEAT

Winter wheat can now be seeded as we have past the fly-safe date of September 27th.  Planting before the 27th risks the infestation of Hessian fly and increases risk of diseases such as barley yellow dwarf.  We now have enough moisture as well to get the seed growing.  Research data suggests that seeding wheat within ten days following the fly-safe date will maximize yields.  Wheat seeded 21 days after the fly-safe date may result in 90% of normal yield and seeding 28 days after the fly-safe date may result in only 77% of normal yield.

It is recommended to not seed winter wheat following wheat or corn due to the increased risk of disease pressure.

Seeding rate for 7.5 inch row wheat is 1.2 to 1.6 million seeds/acre when seeding within two weeks of the fly-safe date and 1.6 to 2 million seeds/acre when seeding after this time period.  The seeding rate for 15 inch row wheat is 1 million seeds/acre.

If seeding wheat in 15 inch rows, choose varieties that will yield best in this row spacing.  Research shows that 15 inch rows may have a yield reduction of 0-15% compared to 7.5 inch rows, although some varieties seeded at 15 inch rows yielded more.

Seed wheat at 1.5 to 2 inches deep.  Seeding depth is most critical in no-tillage wheat as too shallow of wheat is more likely to heave during freeze-thaw cycles.

Choose varieties having the greatest yield potential and disease resistance.  Consult the Ohio Wheat Performance Trial data located at http://www.oardc.ohio-state.edu/wheattrials or stop by the office to pick up a paper copy.

Winter wheat requires more phosphorus and nitrogen than potassium.  Once the soil test level of phosphorus reaches beyond 45 parts per million, then no phosphorus fertilizer is necessary, but below this number phosphorus fertilizer is required to maximize yields.  If the soil test level of phosphorus is only 20 parts per million and the realistic yield goal is 90 bushels per acre then 80 pounds of phosphate fertilizer per acre is required.  It is recommended that 20 to 30 pounds of nitrogen be applied per acre before planting.  Consult the Tri-State Fertility recommendations http://agcrops.osu.edu/publications/tri-state-fertility-guide-corn-soybean-wheat-and-alfalfa  for proper amounts of fertilizer.  Over applying nutrients raises input costs and will likely pollute the environment.

Winter annual weeds, such as cheat (a grass), marestail, cressleaf groundsel, and common chickweed are becoming more prevalent in winter wheat.  Populations are becoming dense enough to decrease yield.  Cressleaf groundsel is poisonous to livestock which if baled with the straw could pose potential problems to livestock.  In no-tillage wheat, the application of glyphosate at 0.75 to 1.125 pounds acid equivalent per acre will control all winter annual species present at the time of application, except glyphosate-resistant marestail.  Winter annual weeds can still germinate after this application, so scout fields to determine if additional herbicides wil be necessary yet this fall as there are more options available than many years ago.  The addition of Sharpen at 1.0 ounce per acre will control marestail and allow for immediate planting of wheat.  Increasing the rate of Sharpen to 2.0 ounces per acre will provide residual control of most winter annual weed species, but will not provide spring residual control.  Dicamba can be added with glyphosate to control marestail, but there is a 10-day waiting period for every 0.25 pound active ingredient applied.

WHAT CAUSED INDIVIDUAL CORN PLANTS TO DIE?

As I have driven the county in the last few weeks, I have seen where individual corn plants turned brown while plants nearby were mostly green.  What caused this observation?  The likely answer is stalk rots.

Why or when are corn plants more prone to stalk rots?  The ideal situation to cause stalk rots is when a large number of kernels have been determined on ears prior to tasseling during less stressful conditions followed by stressful conditions.  In this scenario a large number of kernels developing after pollination require a large quantity of carbohydrates.  If carbohydrates can be made during this period of high demand, then few carbohydrates are moved away from roots and stalks.  However, when the needed carbohydrates are not made, they must come from somewhere and those sources are from the stalk and to some degree the roots.  When these carbohydrates are moved, the roots and stalks deteriorate allowing pathogens to enter the roots and sometimes through the stalk.  Root infection by the fungi can occur prior to pollination, but after pollination root cells naturally begin to die providing a perfect environment for pathogens to infect the roots after this time.  As more roots begin to die, the water conducting tissues are destroyed and the plant will wilt, turn a silver color and then die from lack of water.  The infection will move to the stalk increasing the likelihood of plant death.

What stresses will cause redistribution of carbohydrates during kernel development after pollination?  Any stress that reduces photosynthesis thereby reducing the amount of available carbohydrates will allow stalk rots to develop.  These stresses include leaf disease, hail damage, crowding of plants, drought, soil saturation, lack of sunlight, extended cool weather, low potassium levels, numerous weeds, and insect damage.  The two greatest stresses this season were drought and low potassium levels.  Since we are planting higher plant populations than ever before, this also added to the other two stresses.  A fourth stress that showed up later was grey leaf spot mostly with some corn leaf blight.

There are several pathogens that can cause stalk rots.  Fusarium moniliforme, Fusarium proliferatum, Fusarium subglutinans, Gibberella zeae (also called Fusarium graminaerum and what causes head scab of wheat), Colletotrichum graminicola (Anthracnose), Diplodia maydis, and Macrophomina phaseolina (charcoal rot of soybean) are the pathogens causing a dry rot.  Pythium aphanidermatum and Erwinia dissolvens cause a soft and wet rot and look different than the dry rots.  Symptoms for the Fusarium species includes shredded appearance of the stalk interior and maybe a pinkish discoloration.  For Gibberella dark-brown lesions occur around the nodes and a pink discoloration in the inside of the stalk.  For Colletotrichum, stalks develop dark lesions with tiny black hairs and shiny black blotches developing in the rind and maybe a bluish-black discoloration inside stalk.  For Diplodia, dark rind lesions appear without centric rings and small black structures grow under the surface of the discolored area.  For Macrophomina, the surface of the stalk appears grey and vascular bundles inside appear charred.

What needs to be done now?  Scout fields to determine how many plants have stalk rots regardless of the pathogen causing the damage.  Look for individual plants that died prematurely and pinch the internode of the stalk at and above the brace roots to determine if the stalk is weak.  If the stalk is somewhat soft, the plant may or may not lodge; however, if the stalk collapes, then the stalk will lodge on its own weight.  If strong winds occur the somewhat soft stalks can lodge.  I have already seen lodged stalks, especially in the driest parts of a field.  Make notes of which fields have these conditions and plan to harvest these fields as early as possible.

COVER CROPS AFTER CORN SILAGE

Corn silage harvest is nearing completion in the county.  Corn silage harvest is on the early side this year leaving an opportunity to get cover crops established on those acres.  Earlier planting of cover crops is good.  The touted benefits of cover corps are dependent upon the crop producing forage mass above ground and developing a root system below ground.  More growth is generally equal to more benefits.  In addition to protecting the soil against erosion, cover crops can improve soil quality, provide supplemental forage for grazing or mechanical harvest, can use excess nutrients in the soil, and provide an option for manure application during late fall and winter periods.  The expectation here is that we get some rain so the cover crop can germinate and grow to take advantage of an earlier planting date.

Some cover crop grass options after corn silage include spring oats, spring and/or winter triticale, winter cereal rye, winter barley, and winter wheat. Note that winter wheat even if used only for a cover crop should still lbe planted after the hessian fly-free date, about September 27th.  Legume options are more limited but include crimson clover and winter peas.  Generally these would be included in a mix with one or more of the small grains.  Legumes have the potential to produce some nitrogen for the next crop, but for that to happen they have to be planted as early as possible, preferably at least 4-6 weeks before frost, and make sure the seed is inoculated with the correct Rhizobia bacteria.  Winter peas planted early, probably before the mid-September time frame, will most likely winter kill.  When winter peas are planted late they often will overwinter.  I have talked with farmers who have planted winter peas in the late September to early October time frame and had that crop overwinter.  The downside is those late planting dates generally do not produce much fall growth so if soil cover is the goal, plant earlier.

With regard to the small grain crops, oats (or spring triticale) drilled immediately after corn silage by the end of the first week in September could provide 0.5 to 1.5 tons of dry matter before a killing frost depending upon moisture, fall temperatures, and days until that killing frost.  Since oats and spring triticale winter kills spring termination managemnet is not needed, but from a manure management perspective oats or spring triticale as a cover crop does not provide an option for a winter manure application to a living crop.  Barley when grown for grain in the succeeding year is usually planted between September 15 and 30.  Triticale is generally planted with timing similar to winter wheat and cereal rye for grain production is planted between September 15 and the end of October. With the exception of winter wheat, any of these crops can be planted earlier if the primary purpose is as a cover crop and supplemental forage.  All of these small grians except oats and spring triticale will overwinter and begin growing again in the spring.  The grower must have a plan for the spring forage growth and/or crop termination before planting corn or soybeans.  Remember that both oats and spring triticale will produce more forage in the fall, so either of these crops plus a winter-hardy small grain like winter rye, winter triticale, winter wheat or barley can provide forage later in the fall and again next spring.  It is worth mentioning that cereal rye begins growth early in the spring and it has a rapid maturation so the grower must be prepared to either utilize it as forage early or terminate it early.

Another cover crop and supplemental forage option after corn silage that I am a little reluctant to mention is annual ryegrass.  The reluctance is because some growers have had problems terminating the annual ryegrasss with herbicides in the spring.  Growers who have taken a mechanical harvest off first with a later spring herbicide application have faired better.  If the goal is to provide cover and forage then variety selection for winter hardiness is important.  Mark Sulc, OSU Extension forage specialist, has planted annual ryegrass in early September for several years, and says that one can expect 800 to 2000 lbs. of dry matter/acre by later November and early December, with yields of 3 to 5 tons of dry mtter/acre the following year from improved varieties with good winter survival and with adequate nitrogen fertilization rates.

Another factor that needs to be considered with fall cover crop planting is potential herbicide residual in the soil.  The residual activity of an herbicide in a soil is dependent upon a number of factors including soil type, soil pH, organic matter, rainfall,and temperature.  In addition, when a particular herbicide was applied in terms of time between application and the planting of a cover crop is important.  Unfortunately most herbicide labels may not have information about potential residual effects on cover crops.

Cover crops can provide a number of benefits when they have time to get established and grow sufficient biomass.  A winter hardy cover crop may become part of a nutrient management plan and provide an additional option for manure application.  This year's early corn silage harvest is an opportunity to get some cover crops planted and established in a timely manner.  For more information about cover crop timing, specific species recommendations, seeding rates, and potential forage yields and quality, contact a member of the OSU Extension Ag Crops Team.

PURCHASE LIBERTYLINK SOYBEAN FOR 2017

As 2017 seed is being purchased now, strongly consider purchasing LibertyLink soybean.  LibertyLink soybean is one of the best tools to controlling the increasing density of waterhemp in Auglaize County.  A drastic change in managing weeds in Auglaize County is necessary in 2017 to halt the expansion of waterhemp and the LibertyLink soybean system is one of the best strategies.

Before you purchase LibertyLink soybean be sure you are willing to manage the system to obtain complete weed control.  To maximize weed control in the LibertyLink soybean system till out all weeds before planting or apply a comprehensive burndown herbicide program in no-tillage fields before planting.  A comprehensive soil-applied herbicide is required to obtain early season waterhemp control.  Glufosinate (Liberty) will need to be applied at high rates (32 fluid ounces per acre) to small (less than 4 inch) waterhemp at high spray volume (20 gallons per acre) with medium spray droplets, significant spray pressure, and low sprayer travel speed.  Scouting will be required after the postemergence application to determine the need for a second application.  Glufosinate will also effectively control giant ragweed and marestail (horseweed).  If yellow foxtail, barnyardgrass, and/or volunteer corn is present, clethodim will need to be mixed with glufosinate to maximize control.

PERIMETER WEED MANAGEMENT

Weed density in a field is usually the greatest along the perimeter of the field.  The main reason for this is that weeds are found on the outside perimeter of the field and during harvest the weeds end up on the combine and get spread farther into the field, especialy when harvesting soybean.  One of the major reasons for the weeds along the ouside of the field perimeter is the use of glyphosate being applied outside the field perimeter creating a strip of bare soil allowing for the emergence of weeds.  Allowing these weeds to produce seeds increases the density of weeds inside the perimeter of the field.

One other concern with weeds along the outside perimeter of the field is that when the field is sprayed, the weeds in the perimeter do not receive a full rate of the herbicide.  Therefore, surviving plants are being selected for resistance to the herbicide(s) applied.  Harvesting these weeds are even more problematic than just spreading herbicide susceptible weeds into the field.

The best way to remove these weeds is to mow the outside perimeter of the field.  At this time, we will not stop the greatest amount of weed seeds because many of these weeds are already producing viable seeds.  However, mowing now will at least keep the majority of the seeds on the outside of the field perimeter rather than pulling them into the field with the grain head during harvest.

The most important weeds to control with mowing on the outside perimeter are waterhemp, giant and common ragweed and marestail (horseweed).  Of these waterhemp is of the greatest concern.  We really need to treat waterhemp like Palmer ameranth because more herbicides will be required to manage waterhemp.  My estimation is that waterhemp is present in most of the county compared to last year when most of it was in the western half of the county.

Please take this time prior to harvest to mow the outside perimeter of fields to reduce weed seeds from entering the field.  Mowing now can save significant money if you can keep waterhemp from getting into your field.  If you need help determining if waterhemp is in a field or on the field perimeter call 419-739-6580.

DO I NEED A FERTILIZER CERTIFICATION?

According to Senate Bill 150 passed in 2014, any person applying fertilizer to greater than 50 acres and selling the crops for profit are required to obtain a Fertilizer Certification before September 30, 2017.  The Ohio State University Extension of Auglaize and Shelby Counties will be hosting a Fertilizer Applicator Certification Training on August 29, 2016 from 6:30 p.m. to 9: 30 p.m.  The training will be at the Palazzo, 309 S. Main Street, Botkins, Ohio.  This meeting is especially for those individuals not having a pesticide applicators license, but anyone needing the certification can attend.  Refreshments will be available starting at 6:00 p.m.  Trupointe is sponsoring the cost of refreshments and meeting room.

PRICING STANDING CORN FOR CORN SILAGE

With the drought conditions we are experiencing this growing season, corn silage yields will be much lower than normal and harvest will begin soon.  Therefore, dairy farmers will need to chop more corn than normal to obtain the desired amount of corn silage to feed until next harvest.  This may require dairy farmers to purchase corn silage from corn producers.  In addition, with the lower than normal corn grain yields expected this season, selling corn for silage will greater income than harvesting grain.

When determining a fair market value for corn silage, corn grain yield must be estimated.  To estimate corn grain yield, count the number of ears producing grain in 17 feet 5 inches for 30-inch row spacing (equal 1/1000 of an acre) then husk every 5th ear counting the number of rows and the number of kernels per row on an ear and averaging these for the total number of ears sampled.  Repeat this procedure enough times to get a representative sampling of the field.  To calculate yield, multiply the number of ears by the number of rows per ear by the number of kernels in a row and divide by 110 or 120 this season due to the smaller kernel size that most likely will be observed.  Usually the divisor is 85 or 90.

To obtain the gross return for corn grain, multiply the estimated corn yield by the estimated selling price, which right now is about $2.84 per bushel for new crop corn, and subtract all costs related to harvesting, such as cost of combining, haulinlg charges, drying charges, storage charges and any other harvesting costs.  This will be the net return for grain.  Since corn silage will remove plant material and therefore nutrients, a credit can be accounted for the additional cost of potash and phosphate fertilizers.

Corn silage yield must be estimated, take the estimated corn grain yield and divide by a factor of 0 to 10.0 bushels of corn grain per ton of silage.  If corn yield will be less than 90 bushels per acre, then a factor of 5.5 to 6.0 bushels of corn grain per ton of silage will be most representative.  If corn grain yields are greater than 90, but less than 120 then use a factor of 6.5 to 7 and if greater than 120 use a factor of 7.5 to 8.  Determine the minimum selling price per ton of the silage by taking the net return for grain and dividing by the estimated silage yield.

Based upon nutrient values, 2015 corn silage prices coming out of the silo were $40 to $45 per ton at 35% dry matter content.  Based upon the likely reduced quality of this season's corn silage and the lower costs of alternative feed ingredients, current corn silage value is more likely $30 to $35 per ton.  To obtain the highest price a dairy farmer should purchase corn silage subtract the cost of shrink and storage which is $9 per ton and the cost of harvesting which is $6.90 per ton from the current gross value of corn silage.  Other factors to consider for the dairy farmer is the risk of harvesting at the proper moisture and fermentation. 

Pennsylvania State University http://extension.psu.edu/animals/dairy/business-management/spreadsheet-to-price-standing-corn-for-silage/view   has a spreadsheet available to quickly calculate the negotiating prices for the two parties.

TIME TO SEED ALFALFA

Late summer alfalfa seeding is an excellent time to establish alfalfa.  Fertility is extemely important to successfully establishing alfalfa.  Obtaining a recent soil test analysis is critical to establishing alfalfa.  Soil pH should be 6.8 for soils having a subsoil pH of less than 6.0 and 6.5 for soils having a subsoil pH of greater than 6.0.  If the soil pH is not at these levels, do not seed alfalfa as soil pH needs to be adjusted at least 6 months in advance to seeding.

Consult the Tri-State Fertility Guide http://agcrops.osu.edu/publications/tri-state-fertility-guide-corn-soybean-wheat-and-alfalfa  for phosphate and potash recommendations.  The critical soil test value for phosphorus is 25 parts per million and 88 to 150 parts per million for potassium.  Incorporation of phosphate and potash is preferred to make it more available to seedlings and reduce losses into the environment.  Apply boron at two pounds per acre if the soil test is less than one part per million.  Sulfur may also be needed to maximize alfalfa production.

Choosing the right alfalfa variety for the field is very important for the longevity of the stand and maximizing yield.  Disease resistance characteristics and winter hardiness of varieties can be found from the University of Wisconsin http://www.uwex.edu/ces/forage/pubs/varinfo.htm .  Other traits to consider when selecting varieties include potato leafhopper resistance, low lignin, pea aphid resistance, and Roundup Ready. Consult the Ohio Alfalfa Performance Variety trials http://www.oardc.ohio-state.edu/forage2015/table2.asp  for yield potential in Ohio by location.

Plant alfalfa from August 1 to 15.  The earlier the planting the less likely sclerotinia stem rot will cause problems and the more successful establishment will be.  Plant the highest quality seed available.  Alfalfa seed must be inoculated with nitrogen fixing bacteria for optimal yields.  Treat alfalfa seed with a fungicide to combat soil pathogens.

Seedbed preparation is extremely critical to successful establishment.  Be sure field is devoid of weeds either with tillage or herbicides.  Soil should be smooth and firm if tilled.  Manage plant residues in advance to allow for the greatest seed to soil contact at the time of seeding.  Alfalfa seed should be planted 1/4 to 1/2 inch deep in clay and loam soils, but 1/2 to 3/4 inch deep in sandy soils.

Recommended seeding rate is 80 seeds per square foot or 15 pounds per acre.  The seeding rate can be drastically reduced if using a Brillion Sure Alfalfa seeder.

The only other aspect to consider seeding alfalfa this summer is soil moisture.  At this time much of the county is deficient in soil moisture to successfully seed alfalfa.  If you are in an area that is extremely dry with the cost of alfalfa seed it likely is not a good idea to seed, although one can wait until later to determine if the weather pattern will change before the middle of the month.  Good luck with seeding alfalfa this summer.

SPIDER MITES

Spider mites have been reported in some fields in Auglaize County.  Closely scout fields beginning along the edge of the field since spider mites usuallly start there.  However, scout the most stressful areas of the field as it is possible for spider mites to start inside the field.  Applying a miticide along the field perimeter when some lower leaves are yellowing, high spider mite numbers are in the mid canopy and scattered spider mites in the upper canopy can prevent spraying of the entire field.

TWO-SPOTTED SPIDER MITES

I was in a field in Darke County last week and found a few spider mites on soybeans.  This is early to see spider mites, but we are getting dry.

An adult two-spotted spider mite has eight legs and two spots on the sides of its abdomen.  The two-spotted spider mite has an egg, larva, nymph, and adult life cycle.  The life cycle can be completed in 5-7 days during high temperatures and low humidity and 19 days during normal or below temperatures and high humidity.  Two-spotted spider mites are small and difficult to see, although not impossible, however a hand lens is very helpful.  With a hand lens the marble-shaped clear to pale eggs, larva, and nymphs are visible which is important when scouting.  The two-spotted spider mite lives on the underside of the leaf.

Initial soybean symptoms include a speckled yellow appearance when just a few are present.  As the infestation increases soybean leaves turn yellow followed by bronzing and eventually leaf drop.  Webbing will also be visible on the underside of the leaves as the density increases.

Identification of the speckling/stippling is very important when scouting.  There is no exact threshold for two-spotted spider mites, but a scouting scheme has been determined.  If mites are barely detected in dry pockets and the field margins and injury is barely detected, then nothing needs to be done.  When spider mites become easily detected on underside of leaves along field margins and dry pockets of the field and yellow stippling/speckling is becoming detectable,then monitor field very closely and no miticide is needed yet.  If many plants are infested and plants are showing visible and numerous speckling/stippling with some discoloration of leaves then a rescue treatment is warranted.  Check the entire field to see if there are any spots (most stressed areas) within the field having spider mites.  Many times the spider mites enter the field from the edge and do not move far into the field, unless population changes are not monitored.  If the two-spotted spider mites are only on the edge/margin of the field, then you only need to spray the margin of the field and this may stop them from spreading to the rest of the field.  If all plants in an area, whether inside the field or on the margin of the field, are heavily infested with discolored and wilted leaves, then economic loss is occurring and a miticide application will save the field.  If plants in most of the field are discolored, stunted and plants are dying then a miticide application will only be beneficial if sufficient new growth will occur after application.

The most effective miticides/insecticides include dimethoate, chlorpyrifos, and bifenthrin.  Some of these active ingredients are in premixtures.  Please read the label to make sure you are using the correct rate to control two-spotted spider mite, especially in the tank mixtures.

The key is to scout often and catch the population increase on the margin of the field so you can hopefully only spray the field perimeter.

PREPARING FOR WHEAT HARVEST

Wheat harvest is right around the corner.  There could be some wheat harvested this week if the weather cooperates.  Some wheat has already been harvested and it yielded very well.

Preparing the grain bin is critical to controlling insect problems since wheat is the most likely grain to have pest problems.  Hopefully your bins have already been prepared for filling. It is best to prepare them at least two weeks in advance and preferably longer.  If still needing to prepare the bin be sure ALL grain is removed from the inside and outside of the bin.  Remove all vegetation from around the outside of the bin.  Inspect all augers and be sure they are working properly and lubricate them as necessary.  If wheat will be stored for a long period of time consider spraying an insecticide on the walls and floor of the bin.

Prepare the combine by greasing and oiling all parts of the combine and making sure all parts are in working order.  Check all sickle sections and replace all dull or broken sections.  The wheat stems may be greener than normal this year.

Setting up the combine is extremely critical to harvesting quality grain with minimal loss.  It is recommended to set the cylinder/rotor and concave spacing to 1/4 inch with a range of 1/8 to 1/2 inch.  Set the cylinder/rotor speed to 1000 revolutions per minute (rpm) with a range of 750 to 1350 rpm.  Set the fan speed or choke near the high end with range of medium to high.  The recommended sieve opening is 1/4 inch with a range of 1/8 to 3/8 inch.  The recommended chaffer opening is 5/8 inch with a range of 1/4 to 3/4 inch.

Estimating yield loss when harvesting is very important to properly adjusting the combine.  To check for harvest loss, stop the header and combine speed simultaneously.  Once the header has stopped operating back the combine up about 20 feet then turn off the threshing unit followed by the engine.  Take a one foot square frame and place it three times in the standing wheat ahead of the header and count the number of wheat kernels in each square and take an average.  This is the preharvest count.  Repeat the three square count in the area between the standing wheat and the header.  This is the header count.  Now take the header count and subtract the preharvest count and divide by 20.  This is the header loss.  Twenty is used in the calculation because this is considered to be the number of kernels in a square foot equal to one bushel per acre spread across the entire field.  Go behind the back of the combine and lay the counting frame down three times in the area between the tires counting the seeds in each square and obtaining an average.  This is the separator count.  Take the separator count and subtract the header count and divide by 80 (number of kernels per square foot behind separator discharge to equal 1 bushel per acre with no spreading device).  Eighty is replaced by 65 if a bat type spreader is used, by 50 if a straw chopper is used, and by 25 if a chopper and chaff spreader are used.  The goal is to have harvest losses below 2% of total yield.  To summarize combine settings, operation and estimating yield loss check out the publication "Harvesting Wheat" from Kansas State University at https://www.bookstore.ksre.ksu.edu/pubs/MF2026.pdf

Once the moisture of the wheat reaches 20% begin harvesting.  Harvesting at this moisture and air drying will result in higher test weight and quality.  Harvesting 20% moisture when field conditions are fit will reduce the chance that rain will reduce grain quality from sprouting and vomitoxin (which should not be a problem this year).  There is rain in the forecast for the first three days of next week.  Harvest wheat before it reaches 14% moisture because kernel damage will occur below this moisture.  Wheat can lose 2.5% moisture each day.  Check with your local elevators to determine what their discount rate is for delivering wheat above 14%.  Do not fill the bin beyond 9 feet when air drying wheat because wheat reduces air flow more than corn.

MANAGING KEY WEEDS IN ROUNDUP
READY SOYBEAN WITH
POSTEMERGENCE HERBICIDES

As the temperatures warm and while driving down the roads, I am observing weeds becoming larger in soybean fields.  Some fields from the road appear to be mostly weed free, but this is not the majority.

Key weeds to look for in soybean include waterhemp, giant and common ragweed, and marestail.  These weeds are key due to the frequency of resistant biotypes.  Nearly all waterhemp is resistant to ALS-inhibitors (Group 2).  About half of waterhemp populations are resistant to glyphosate (Group 9).  A few waterhemp populations may be resistant to PPO inhibitors (Group 14).  There are waterhemp populations with resistance to glyphosate and Group 2 herbicides and a rare case of resistance to all of three types of herbicides.  Nearly all marestail is resistant to glyphosate and ALS-inhibitors (Group 2).  Many giant and comon ragweed populations can be resistant to glyphosate and ALS-inhibitors (Group 2).  Two additional weeds specific to this growing season are curly dock and yellow nutsedge.

Take the time to scout for these weeds, especially waterhemp and giant ragweed.  Do not let waterhemp become larger than four inches in height and giant ragweed larger than 6 inches in height, because at those sizes they begin to grow rapidly and become more difficult to control with the initial application and any secondary applications.

To control curly dock, yellow nutsedge and weeds surviving tillage, apply glyphosate at 1.5 pounds acid equivalent per acre (44 fluid ounces per acre of Roundup PowerMAX).  A second glyphosate application likely will be necessary to obtain complete control of yellow nutsedge and maybe curly dock.  Another option may be to add Classic at 2/3 ounce per acre to help on yellow nutsedge and maybe curly dock.  For all other weeds the minimum glyphosate rate should be 1.125 pounds acid equivalent per acre (32 fluid ounces per acre of Roundup PowerMAX) depending upon weed size.  If lambsquarters is present in a field include additional nonionic surfactant at 0.25 to 1% volume per volume depending upon the concentration of the glyphosate formulation.

The most complete herbicide to control most local weeds resistant to glyphosate and Group 2 herbicides, with the exception of marestail, is Flexstar GT applied at 3.75 pints per acre.  Include a methylated seed oil (MSO) at 1 to 1.5 pint per acre plus ammonium sulfate (AMS) at 8.5 pounds AMS per 100 gallons of spray volume.  To maximize control apply with a nozzle producing medium spray droplets and use a spray volume greater than 15 gallons per acre.

To control glyphosate-resistant marestail apply FirstRate at 0.45 ounce per acre with glyphosate.  Just know that not all marestail will be controlled.  To control waterhemp alone, Cobra (10 to 12.5 fluid ounce per acre), Flexstar (1.3 pints per acre), and Ultra Blazer (1.5 points per acre) are equally effective.  To control the ragweeds alone, apply Flexstar at 1.3 pints per acre.

SCOUT FIELDS CAREFULLY WHEN PREPARING

FOR POSTEMERGENCE CORN HERBICIDES

Weeds are becoming fairly large in early planted corn without a soil-applied herbicide.  In no-tillage and conventional tillage corn, scout closely for waterhemp and other weeds.  Waterhemp is in the pigweed family.  Waterhemp leaves are longer and narrower and shinier compared to redroot and smooth pigweed having ovate leaves.  There is no hair on the stem and petiole (structure holding leaf to stem) of waterhemp compared to smooth and redroot pigweed.  The base of a waterhemp stem may be red like smooth and redroot pigweed or green.  The cotyledons of waterhemp are smaller, more pointed at the tip and egg-shaped compared to the longer, wider, and linear cotoyledons of smooth and redroot pigweed.  It is extremely critical to properly identify waterhemp from smooth and redroot pigweed as waterhemp is likely resistant to glyphosate (Group 9) and ALS-inhibiting herbicides (Group 2).

In no-tillage fields scout to make sure marestail (horseweed), giant and common ragweed were completely controlled by the burndown herbicides.  These weeds are likely resistant to Group 2 and 9 herbicides.

If any marestail or ragweeds survived the burndown and waterhemp is also present, Liberty could be applied to LibertyLink corn hybrids.  Apply the Liberty at maximum rate in a spray volume of 20 gallons per acre achieving medium spray droplets.  If the corn hybrid is only resistant to glyphosate and these weeds are present, apply Callisto, Capreno, Impact, Laudis, or Status plus atrazine (0.5 to 2.0 pounds/acre) plus glyphosate.  Follow all label directions, especially regarding crop stage and adjuvants.

SCOUT FIELDS FOR FROST DAMAGE

On Monday, May 16th, temperatures in the county were below 32 degres F.  That morning South of Minster, I observed frost on the lowest leaves in a wheat field!  When scouting fields last Friday, May 20th we observed frost/freeze damage in corn and soybean fields.  Some level of frost damage was observed in most corn fields in the county, especially north of Rt. 33.  Fortunately, I did not see any stems damaged, just leaves.

The death of the main growing point of soybean was observed in multiple fields.  In addition damage was observed on the hypocotyl arch of soybeans just emerging at the time of frost.  It appeared that most of these plants will survive.  The biggest concern is how plants will recover in which the main meristem was killed.  Plants were flagged in a field to determine the likelihood of recovery.

Based upon these observations, be sure to scout fields looking for damage.  The most obvious symptoms of frost damage include brown to grayish-green to black leaves and/or stem tissues.  Yellow plants have nothing to do with frost damage, just cold cloudy weather.

NITROGEN MANAGEMENT IN CORN

Now that the earliest planted corn in the county is at the V3 (3rd collar visible) stage, it is time to think about side-dressing nitrogen.  When is the proper time to apply nitrogen to corn?  Ideally nitrogen should be applied when it is needed.  Corn begins rapid nitrogen uptake at the V9 stage and continues large nitrogen consumption through tasselling.  When side-dressing nitrogen to small corn, a second nitrogen application at tasselling would be advantageous to the corn and allow for a reduced amount of nitrogen for the season.

Things to consider: Apply urea with Agrotain to reduce volatility; Inject nitrogen in high residue situations; Know the nitrogen efficiency of the hybrids being grown; and Prevent weeds from stealing the nitrogen.

How much nitrogen should be applied?  If manure was applied to the field then conduct a pre-sidedress nitrate test to determine the need for additional nitrogen.  These tests have been very accurate when manure has been applied.  The next best method to determining the amount of nitrogen to apply is the use of nitrogen sensors.  For the sensors to work best, a high nitrogen rate strip (>250 pounds nitrogen per acre) is required.  One other way to determine the amount of nitrogen to apply is to use the Maximum Return to Nitrogen (MRTN) model.  This model takes into account the price of nitrogen and corn to determine the most economic rate.  The MRTN recommendation calculator can be obtained at http://extension.agron.iastate.edu/soilfertility/nrate.aspx      With the current low commodity prices, using the most economical rate of nitrogen makes sense economically as well as environmentally.

WHEAT DISEASE OBSERVATIONS

Since last week, I have scouted over 30 wheat fields.  Wheat is in the boot to full head stage.  That means wheat will begin flowering this week, but most of it will not flower until next week.  The most prevalent diseases in fields are stripe rust and powdery mildew.  Only about 20 to 25% of fields have either of these diseases.

Stripe rust appears as rows of orange pustules.  I am seeing it appear first on the flag leaf and then moving down into the canopy.  You can see yellowish circular patches in fields as you drive by.  Stripe rust is a very explosive disease, so applying a fungicide as quickly as possible is important.  If flowering will not occur until after 5 days from now and rust is present, then apply propiconazole as soon as possible.  If rust is present in just a single spot in the field and flowering will occur within three days then apply Prosaro or Caramba to control stripe rust, powdery mildew, and head scab.

When about 20% of wheat heads are flowering it is time to apply Caramba or Prosaro to control head scab.  Research indicates that wheat yield can be improved when fungicides are applied even to a moderately resistant variety if weather conditions are conducive to the disease.  Visit the following web site to obtain the latest scab forecasting prediction in determining the need for a fungicide application:  http://www.wheatscab.psu.edu

PREPARING FOR FUSARIUM HEAD SCAB

Wheat is progressing along in the county.  The range in wheat stage is from flag leaf collar visible to head emergence.  Most of the wheat is in the boot stage meaning flowering is right around the corner.  On average it takes five days from full head emergence to flowering (anthers become visible) with flowering occurring for about five days.  This means wheat could begin flowering in the county as early as the middle to end of next week.

The current weather forecast from now through May 22nd is slightly below normal temperatures, which will slow the development of the wheat, to slightly above normal temperatures after May 22nd till the end of the month.  Rainfall is forecasted to be average to above average through the rest of the month, increasing the risk for fusarium head scab.

Fusarium graminearum is the fungus that causes Fusarium head scab.  It survives on corn, wheat, and grass residue producing spores during warm wet humid conditions which are blown through the air over long distances or splashed up onto the florets.  The fungus infects wheat during the flowering stage.  A two to three day period of high humidity and precipitation during flowering is ideal for infection of wheat.  Head scab causes floret sterility, poor test weights due to shriveled kernels, and yield loss.  In addition, the pathogen produces a mycotoxin called vomitoxin which is harmful to humans and animals.  Vomitoxin levels exceeding one and five parts per million is unfit for human and animal consumption, respectively.

With the forecast of rain being high over the next few weeks carefully scout wheat fields for the development of flowering and use the scab risk tool http://www.wheatscab.psu.edu  to help monitor the risk for head scab for making a fungicide application.  The current scab risk model is high for our area.  A fungicide application of Prosaro or Caramba at flowering will reduce head scab and vomitoxin.  These fungicides applied four to six days after flowering can still reduce head scab and vomitoxin.  Last season wheat yield was improved by at least 15 bushel per acre and dockage reduced by $1.00 per bushel in a field having a fungicide application at flowering.

The greatest yield and the lowest vomitoxin levels are achieved when the most resistant wheat variety is planted and an effective fungicide is applied.  Head scab also affects barley.  For more information regarding head scab and scab risk model visit the following web pages:  http://ohioline.osu.edu/factsheet/plpath-cer-06   and  http://ohioline.osu.edu/factsheet/plpath-cer-03

ALFALFA HARVEST

Alfalfa harvest is right around the corner.  I looked at a field of alfalfa on Monday (5-2-16) and it averaged 16 inches in height with no visible buds.  If alfalfa weevil damage is at economic levels, cut the alfalfa at the next possibile dry period.

When is the right time to harvest alfalfa?  There are many ways to determine alfalfa harvest, growth stage, growing degree days (GDD), "scissor clipping" method, and predictive equations for alfalfa quality (PEAQ) using a "forage quality stick" or a chart.  The desired use of the alfalfa will depend upon when to harvest.  For high producing lactating dairy cows the best quality alfalfa hay is desired; for beef and dry cows the quality can be lower.  Harvest alfalfa at 28 inches or early to mid-bud stage for lactating dairy cows.  When using PEAQ a relative feed value (RFV) of greater than 150 should be the goal, but since there is a 15% loss of RFV at harvest, harvest at a RFV of greater than 165.  If harvest will take a week, harvest at an even higher RFV.  To perform a PEAQ, choose a two square foot area in the field, determine the most mature plant within the square and then measure the height of the stem from the soil surface to the tip of the stem (not leaves).  Randomly choose 5 other areas of the field and repeat procedure.  Use a chart or the forage quality stick using the plant height and stage.

Mow alfalfa to a 2" height unless plants are under moisture stress and may be contaminated with soil or rocks.  Be sure disc bine knives and sickle sections are sharp.  Manage the cut hay to retain as many leaves as possible, 71% of forage value is in the leaves!  If alfalfa weevil were present before cutting, scout regrowth for damage to determine if an insecticide application is warranted.

WHAT IS THAT YELLOW WEED IN FIELDS?

There are fields that have not been tilled yet or had a burndown herbicide program applied yet.  At this time you can see a weed  in these fields that is about three to three and one half feet tall.  It has a reddish grooved and hollow stem with rounded lobes on the leaves and numerous small yellow flower heads at the top of the plant.  This plant is cressleaf groundsel.  Seeds on this plant are carried by wind currents to other areas once they mature.

This plant is poisonous somewhat poisonous to cattle and horses.  I have seen a few plants in some hay fields.  Any time you see cressleaf groundsel in hay fields or pastures, be sure to remove it so animals will not be harmed.  Cressleaf groundsel should not kill cattle or horses.  Poisoning is most often chronic, taking several weeks to show symptoms.  Symptoms in cattle include scaly noses, rough coats to listless, decreased appetite with digestive problems, jaundiced and/or photosensitivity.  Calves can develop swollen jaws.  Horses can become nervous and have "sleepy staggers" with long term exposure leading to liver damage.

For control in grass pastures apply 2,4-D ester at 1.5 pint per acre plus dicamba at 0.5 pint per acre or remove them by hand if only a few exist.  Hay or silage can be harvested 37 days after application.  Wait seven days before allowing lactating dairy cattle to forage and remove cattle 30 days before slaughter.  In no-tillage soybean and corn fields apply glyphosate at 1.125 pounds acid equivalent per acre plus 2,4-D ester at one pint per acre.  Wait seven days after application before planting soybean and corn.

MANAGING WATERHEMP IN CORN

Now that the weather is sunny and warm after April started cold, wet, and snowy and we are nearly mid-April, it is time to get crops planted.  This week I will focus on managing waterhemp in corn.  Waterhemp is related to the pigweeds and looks very similar to them.

Choosing the right herbicide based upon the weeds in a field is very important to maximizing weed control!  Last year I observed 21% of soybean fields in Auglaize County having waterhemp at harvest time.  This is very alarming!  The waterhemp germinates late into the season similar to giant ragweed, making perfect control difficult.  Also, the waterhemp is resistant to glyphosate and ALS (group 2) herbicides.  There is a possibility the waterhemp is resistant to atrazine as well, but this has not been confirmed in Ohio at this time.

The most effective strategy to controlling waterhemp in corn is to apply the full rate of an effective preemergence or soil-applied herbicide followed by a postemergence herbicide(s) having residual control mixed with glyphosate.  This strategy should only be necessary in fields having moderate to high densities of waterhemp or to ensure low and moderate density populations do not increase.  A total postemergence herbicide program having residual control will most likely NOT manage a moderate to high density waterhemp population because the application will need to be applied too soon to minimize weed competition with corn resulting in too short of residual waterhemp control.  This strategy may work in a low density population, but there is no guarantee.  For no or low to moderate density waterhemp populations, the application of two thirds to three quarters rate of an effective preemergence product followed by a late postemergence product having no residual control could be effective.

The most effective preemergence herbicide(s) include:  Acetochlor plus atrazine (rates containing at least 1.5 pounds active ingredient of atrazine); Acuron; Lumax; Lexar EZ; and Verdict plus acetochlor. Postemergence products to be mixed with glyphosate containing the longest residual control include: Callisto Xtra; Atrazine at the highest remaining rate following a preemergence application of atrazine; or an effective postemergence herbicide mixed with atrazine at the highest remaining rate following a preemergence application of atrazine. Glyphosate mixed with Solstice is the most effective postemergence herbicide applied late in corn having some residual control.  The next most effective postemergence herbicides mixed with glyphosate providing some residual control and applied late include: Callisto; Callisto GT (Roundup Ready corn only); Capreno; Halex GT (Roundup Ready corn only); Impact; Laudis; Realm Q; and Revulin Q.  Status mixed with glyphosate will control waterhemp as good, but has no or very little residual control.  Glufosinate plus atrazine applied to LibertyLink corn can be effective, but it must be applied to small waterhemp and following a full rate of the most effective preemergence herbicide.

Use the maximum rate of the postemergence herbicides.  For postemergence treatments be sure to include the most effective adjuvant for non-glyphosate products.  Read and follow label directions, especially as it relates to the maximum size of corn for postemergence products.  Glyphosate can only be applied to Roundup Ready corn.

If giant ragweed is also present within these fields, any of these programs will work.

SCOUTING FOR POWDERY MILDEW
IN WINTER WHEAT

Winter wheat leaf diseases have been found in some fields in Ohio.  Leaf rust and powdery mildew had actually been reported late last fall with the warm weather.  The warm winter MAY make leaf diseases more prevalent this season.  The only way to know if the disease is present and to save money from an unnecessary application is to scout fields closely for the presence of disease.  Begin scouting areas of the field with the densest and most lush growth along with areas of higher relative humidity.

Powdery mildew is recognized as small, white powdery or cottony pustules scattered over the leaves and stems.  The pustules can form on the upper and lower sides of the leaf.  Chlorotic (yellow) patches may later surround the pustules.  As leaves age small black fruiting bodies called clistothecia develop within the white pustules.

The pathogen spreads during high relative humidity with temperatures between 60 and 72 degrees F.  Dense lush growth reduces air movement helping to support higher relative humidity and spread of the pathogen.  Wide row wheat should reduce the risk of disease development due to greater air flow.

Wheat varieties differ in their susceptibility to the pathogen. Check the varieties planted to determine the level of resistance.  A susceptible variety will need to be sprayed before a resistant variety.  The threshold for powdery mildew is 2-3 lesions per leaf located below the flag leaf.  Caramba, Tilt (propiconazole), Aproach Pima, and Quilt Xcel provide the most effective control of powdery mildew.  If a fungicide application is warranted and Aproach Prima or Quilt Xcel will be chosen, apply before the flag leaf is fully emerged.  Both of these products contain a strobilurin fungicide that has been shown to increase the amount of vomitoxin if fusarium head scab becomes a problem when these fungicides are applied when the last ligule is exposed.  Fungicide applications made too early may warrant a second application as the top two leaves have the greatest impact in maximizing yield.

MANAGING SOYBEAN SEEDLING DISEASES

Pythium, Phytophthora, Rhizoctonia, and Fusarium are soilborne, soybean seedling diseases while phomopsis is a seedborne seedling disease.  Pythium and Phytophthora are especially damaging soybean pathogens in Ohio and are not a true fungal pathogen, but water molds.

Phytophthora, Pythium, and Rhizoctonia can attack and rot seeds, seedlings, and cause post-emergence damping off.  Fusarium will damage seed and seedlings.  Phytophthora and Pythium produces tan-brown, soft rotted tissue and can only be distinguished using a microscope.  The characteristic symptom of Rhizoctonia is a firm rusty-brown decay of sunken lesions of roots or lower stem.  Fusarium causes light to dark brown lesions on roots that may spread over much of the root system and may appear shrunken.

Phytophthora sojae, the causual agent, can survive in the soiil for up to 5 to 10 years on decomposing soybean tissues. There are over 70 strains of the Phytophthora sojae.  Soybean is the only known host of the pathogen.  Phytophthora sojae is favored by saturated, warm soils.

There are many (>9) different species of Pythium that can infect soybean as well as other crops.  Most Pythium species are favored by cool and wet soils, although some are favored by saturated, warm soils.  Due to the long term use of metalaxyl as a seed treatment there are strains of the Pythium species that are insensitive or resistant to metalaxyl.

Rhizoctonia solani has a wide host range. There are two strains of the pathogen that can infect soybean having different optimal conditions to infect soybean.  Warm and wet soils are the most common conditions causing infection.

There are many different species of Fusarium that can infect soybean.  Some species prefer warm and dry soils while others prefer cool and wet soils.  Some Fusarium species have a broad host range.

Seed and seedling diseases are difficult to manage and different management strategies are required for the different species.  In general the diseases can be reduced by planting good-quality seed in well-drained, non-compacted soils.  Delaying planting until soils are >55 degrees F and relatively dry to allow for rapid emergence and growth can be beneficial.  Crop rotation and tillage may be of some benefit.  Phytophthora can be somewhat managed with soybean varieties.  There are six different genes (Rps1a, Rps1b, Rps1c, Rps1k, Rps3a, and Rps6) available in soybean varieties to help manage Phytophthora.  Choose varieties with as many genes as possible and rotate the genes over time because a shift in the Phytophthora population can occur making the resistance ineffective.  In addition to host plant resistance plant soybean varieties with excellent partial resistance or field tolerance as this reduces the infection of all or nearly all of the Phytophthora races.  Despite the effectiveness of partial resistance, it is only expressed after the cotyledon stage of development making it vulnerable during germination and emergence.

Fungicidal seed treatments are the only other means of reducing seed and seedling diseases.  For Pythium and Phytophthora include metalaxyl, mefenoxam, or ethaboxam.  For Rhizoctonia and Fusarium active ingredients such as pyraclostrobin, fluxapyroxad, ipconazole, fludioxonil, sedexane, prothioconazole, or penflufen can provide control.  The best way to manage the diseases is to apply two or more fungicides to the seed.  Acceleron, Inovate Pro, Intego Suite, Intego Solo, Cruiser Maxx, Cruiser Maxx plus Vibrance, and Evergol Energy plus Metalaxyl have been shown to provide effective control of these diseases other than for the insensitive Pythium strains.

With the current low soybean prices, the most important part of soybean seed treatment is to include fungicides to manage these diseases.  Other types of seed treatments likely will not provide the same return on investment as fungicide seed treatments.

FACTORS AFFECTING SOYBEAN YIELD

Dr. Laura Lindsey, The Ohio State University Extension Specialist for soybeans and wheat, conducted a research project funded by the Ohio Soybean Council from 2013 to 2015.  The study was conducted throughout the state of Ohio.

Soil test results showed that 35% of soybean fields in Ohio in the study had phosphorus levels below the critical level of 30 parts per million (ppm) {Mehlich III extraction}, 36% were in the maintenance range of 30 to 55 ppm, and 29% were in the drawdown range of greater than 55 ppm.  Soybean yielded 7 bushels per acre (bu/A) less when the soil test phosphorus values were below the critical level.  Soybean yield did not increase when soil test phosphorus values were in the maintenance and drawdown ranges.

Soil test results showed that 21% of soybean fields in Ohio had potassium levels below the critical level, 34% were in the maintenance range and 45% were in the drawdown range.  Soybean yielded 4 bu/A less when the soil test potassium levels were below the critical level.  Soybean yield did not increase when the soil test potassium levels were in the maintenance and drawdown ranges.

Twenty-two percent of soil tests had a pH of 6.0, 60% had a pH of 6 to 6.8, and 18% of soil samples had a pH greater than 6.8.  Soil pH levels had no effect on soybean yield.

One percent of soils had a cation exchange capacity (CEC) of 0 to 5, 21% of samples had a CEC of 5 to 10, 70% of samples had a CEC of 10 to 20, and 8% of samples had a CEC of greater than 20.  Higher CEC levels are generallly considered to be better because of a greater capacity to hold onto nutrients, but soybean yield decreased wtih increasing CEC levels.  A high percentage of the soils with higher CEC had a higher clay content which can lead to poorer drainage and more disease problems which could have been the driver to reduced soybean yield.

If tissue nitrogen levels were below the sufficiency range then soybean yield decreased by 8 bu/A.

If soybeans were planted before May 16th yields increased 3 bu/A compared to planting after May 16th.

Soybean cyst nematodes were present throughout the state of Ohio.  Greater than 80% of soybean fields in Ohio in this study have detectible levels of soybean cyst nematodes.  Where soybean cyst nematodes were detected, 75% of farmers were not aware of the problem.  Soybean yields decreased three bu/A if there were greater than 200 soybean cyst nematode eggs per 100 cubic centimeters of soil.

Soybean yields increased 6 bu/A if Rhizobia inoculant was added to the seed at the time of planting.

Sample soils in a random pattern, in a grid pattern, or by management zones every 2 to 3 years to a depth of 8 inches.  This is important to maintaining phosphorus and potassium levels in the maintenance range in order to maximize soybean yield.

FUSARIUM HEAD BLIGHT OR SCAB

Fusarium head blight (scab) has caused substantial losses in wheat production since 1991 and again in 2015.  During severe infestations of Fusarium head blight, wheat yields can be reduced by as much as 50% with additional financial losses caused by the presence of mycotoxins.

Fusarium head blight is caused by the pathogen Fusarium graminearum (asexual stage of fungus) and Giberalla zeae (sexual stage of fungus).  Fusarium graminearum overwinters on infested corn stalk, wheat straw, and other host plants.  The fungus produces asexual spores which are dispersed to plants and residue from rain-splash or wind.  During warm, humid, and wet weather conditions the sexual stage of the fungus develops on infested plant debris.  Perithicia form on the surface of the residue discharging sexual spores called ascospores.  The ascospores are picked up by turbulent wind currents and may travel great distances in the air landing on wheat heads.  During wheat anthesis (flowering) extruded anthers are thought to be the site of primary infection.  Infection may occur with as little as two or three days of light to moderate rainfall or greater than 90% humidity with temperatures between 59 and 85 degrees F.  If anthers are infected just after emergence, the fungus will colonize and kill the florets and kernels will not develop.  If florets are infected after anthesis, kernels end up shriveled and wilted.  Kernels colonized during kernel development may not appear to be affected, but may be contaminated with mycotoxin.

Infected kernels used as seed for a subsequent wheat crop will cause seedling blight unless seed is cleaned thoroughly and treated with a fungicide.

The first symptoms of Fusarium head blight occur about 18 days after anthesis.  Diseased spikelets exhibit premature bleaching as the pathogen grows and spreads within the head.  One or more spikelets located in the top, middle, or bottom of the head may become bleached and may progress throughout the entire head.  If the environment is warm and moist, aggregations of light pink/salmon colored spores may appear on the rachis and glumes of individual spikelets.  As time progresses, bluish-black spherical bodies may appear on the surface of affected spikelets.  The infected kernels often have a rough, shriveled appearance, ranging in color from pink, soft-grey, to light-brown.

Besides lose of wheat yield and quality Fusarium graminearum produces mycotoxins (fungal chemicals harmful to animals and humans).  The major toxin produced by Fusarium graminaerum in association with Fusarium head blight is deoxynivalenol (DON).  DON is sometimes called vomitoxin because of its deleterious effects on the digestive system of swine and other monogastric animals.  Humans consuming wheat products contaminated with DON demonstrate symptoms of nausea, fever, headaches, and vomiting.  The USDA recommends that DON levels in human foods not exceed one part per million.  According to the U.S. Food and Drug Administration the maximum DON level allowed in finished swine and beef and poultry feed is one part per million and five parts per million, respectively.

Integrated pest management is the only way to manage this disease. Plant a moderately resistant variety, eliminate corn and wheat residues with tillage and/or crop rotation, and apply Prosaro, Caramba, or Proline after heading until six days after anthesis.

OBSERVING WEED POPULATIONS
IN AUGLAIZE COUNTY

Since 2006 Ohio State University Agriculture and Natural Resources Extension Educators have been observing weeds in soybeans prior to harvest.  A weed survey was conducted again in 2015.  I traveled 77 miles of Auglaize County starting in the southern part of the county on St. Rt. 364 making an outline of the county ending near New Knoxville.  Every soybean field along the route was evaluated as weed free, low, moderate, or severe weed infestations.  Only 18% of soybean fields were weedfree.

Forty-four percent of soybean fields had some level of marestail (horseweed) present.  Little change occurred in the marestail density compared to 2013 which was 48%.  A closer look shows great improvement in control of marestail.  In 2013 20% of fields observed had a severe infestation compared to only 8% of fields in 2015.  There was a 7% increase in the number of fields having a moderate infestation.

The next most prevalent weed observed in soybean fields in 2015 was giant ragweed.  Thirty-one perent of fields have some frequency of giant ragweed compared to 46% in 2013, a great improvement.  Only two percent of fields had severe infestation compared to 10% in 2013 and only 24% of fields had a low infestation compared to 2013.

Volunteer corn was observed in 30% of soybean fields in 2015, a 9% increase over 2013.  Seven percent of fields had a moderate volunteer corn infestation compared to zero percent in 2013.

Waterhemp, a pigweed species, was observed in 21% of soybean fields in 2015, a 15% increase from pigweed that was reported in 2013.  The pigweed reported in 2013 may or may not have included waterhemp.  In 2015, 16% of fields had low, two percent moderate, and three percent severe infestations of waterhemp.  The increase in the amount of waterhemp is very alarming because a single waterhemp plant will easily produce 100,000 seeds, but can produce millions of seeds.

Grasses, mostly giant foxtail, were observed in 11% of fields in 2015 comparerd to two percent in 2015.  This increase was likely due to the excessive water in 2015.

Common ragweed, common lambsquarters and velvetleaf were observed in nine, three, and two percent, respectively in 2015, which was very similar to 2013.

Knowing what weeds are present in a field at harvest is important to planning weed control strategies for next season. If weed control is less than weedfree, especiallly for species known to be resistant to glyphosate, then drastic changes in weed control is required.

CONTROL OF GIANT RAGWEED

Giant ragweed is a summer annual weed species producing up to 11,000 seeds per plant without competition.  Giant ragweed can begin emerging in late March if weather conditions are conducive.  Giant ragweed will continue emerging into July, making weed managment more difficult.  Giant ragweed plants can reach up to 15 to 18' tall.  Giant ragweed can be identified by its opposite leaves and three lobed leaf margin.

Giant ragweed is best controlled by applying a residual herbicide at planting followed by one to two postemergence herbicide applications, depending upon giant ragweed density and removal of plants before planting.  There are more effective corn herbicides to manage giant ragweed than in soybean, so eliminating all giant ragweed plants in corn will allow for more effective control in soybean.

Giant ragweed populations in the area may be resistant to glyphosate (Group 9), ALS-inhibiting herbicides (Group 2), and possibly PPO-inhibiting herbicides (Group 14).  Plants may be resistant to one or potentially all of these herbicides.  If a giant ragweed population is resistant to all of these types of herbicides, then glufosinate applied to LibertyLink soybeans will control giant ragweed.

For corn an application of 2,4-D plus a high rate of atrazine prior to planting will control emerged giant ragweed, although grasses will not be controlled.  If plants become large add glyphosate at 1.5 pounds acid equivalent/acre or Gramoxone to the 2,4-D plus atrazine.  Most effective preemergence treatments are those containing atrazine and another broadleaf herbicide.  These other herbicides include Acuron, Lexar, Lumax, SureStart/TripleFlex, Instigate, Hornet, Balance Flexx, Corvus, and Verdict/Sharpen.  The most effective postemergence treatments include dicamba, Status, Impact/Armazon, mesotrione products, and Laudis.  The addition of atrazine and/or glyphosate in Roundup Ready corn to the above mentioned products will improve control.

For no-tillage soybean a burndown application of 2,4-D (1 pint/A for small plants and 2 pints/A for lar plants) + glyphosate at 1.125 to 1.5 pounds ae/A or a high rate of Liberty plus metribuzin applied before planting should control emerged giant ragweed.  Sharpen, Optill Pro, or Verdict can replace 2,4-D if planting can't be delayed, but really large plants may not be controlled.  Residual herbicides need to be included.  The most effective residual herbicides for controlling giant ragweed are those containing chlorimuron or cloransulam.

In non-GMO soybeans apply FirstRate (0.3 oz/A) or Flexstar (1.3 pt/A) or FIrstRate plus Flexstar to control giant ragweed.  If giant ragweed are present that are resistant to FIrstRate be sure to apply the Flexstar to small plants and consider a second postemergence application of Cobra.

In Roundup Ready soybean apply glyphosate at 1.5 pounds acid equivalent per acre and follow with glyphosate at 0.75 pounds per acre three weeks later.  If giant ragweed are resistant to glyphosate and ALS-inhibiting herbicides include Flexstar (1.3 pt/A) in the first application and scout to determine if Cobra will need to be added to the second postemergence treatment.

For LibertyLink soybeans apply glufosinate at 29 fluid ounces/A when giant ragweed plants are 4 to 8 inches tall.  Apply glufosinate three weeks later at 22 fluid ounces/A if needed.

NORTHERN CORN LEAF BLIGHT

Northern corn leaf blight was the number one corn disease in 2015 in Auglaie County and the rest of the state.  Northern corn leaf blight has been increasing in frequency and intensity over the past decade.

There are four known races of the fungus causing northern corn leaf blight.  The fungus causing northern corn leaf blight overwinters as mycelia and conidia on corn residues left on the soil surface.  As temperatures rise in the spring spores are produced on the corn residue that splash or are wind-blown onto corn leaves.  Infection occurs during wet and humid weather with temperatures between 64 and 81 degrees.  The fungus requires six to 18 hours of water on the leaf surface to cause infection.

Northern corn leaf blight can reduce yield when conditions are favorable for early development of the disease by reducing photosynthetic area of leaves.  If lesions reach the ear leaf or higher two weeks before and after tasseling, yield loss can occur.  Corn yield can be reduced by 30 percent if lesions are present prior to or at tasseling.  If lesions do not appear on upper leaves until late in the season, yield losses are minimal.  Northern corn leaf blight can contribute to stalk rot and lodging.

The most cost-effective method to managing northern corn leaf blight is to plant resistant hybrids.  There are two types of resistant hybrids available to control northern corn leaf blight: partial resistance and race-specific resistance.  Partial resistance protects corn from all four of the known races of the fungus.  Partial resistant hybrids are most common, but there are some hybrids with partial and race-specific resistance.  Some seed companies rate the degree of resistance; however, be careful when comparing hybrids as not all companies use the same scale.  Where northern corn leaf blight is a chronic problem select hybrids with race-specific resistance.

Another method of controlling northern corn leaf blight is to manage corn residue.  Practices that encourage decomposition of corn residue will reduce the amount of fungus.  In no-tillage or reduced tillage fields with a history of northern corn leaf blight a two year rotation out of corn may be required to reduce the amount of disease.

Fungicides are only needed to control northern corn leaf blight when susceptible hybrids are planted.  The most effective fungicides include Aproach, Headline, Proline, Folicur, Quilt Xcel, Aframe Plus, Prima, Fortix, Headline AMP, and Stratego YLD.  Fungicides applied at tasseling [VT] to early silking [R1] have the greatest likelihood of economic return.

HOW TO CONTROL WINTER ANNUAL WEEDS

Many soybean fields had marestail (horseweed) in them this fall.  In a 78 mile drive of the county marestail was found in 44% of fields.  With the windy weather over the last two weeks seeds were dispersed throughout the county.  I have seen some fields with a decent amount of winter annual weeds.  Marestail starts to emerge as seeds fall off the plant, so they are already out there, but very small at this time. Now is the time to control winter annual weeds, especially marestail, biennial weeds and dandelion.  Controlling marestail in the fall can be the difference next year between nearly perfect control and very poor control.  If marestail are not controlled in the fall and if weather causes delays in applying burndown herbicides in the spring the marestail can quickly get too large to be completely controlled and cause increased costs of herbicides.

The most cost effective treatment for most species and allowing flexibility to plant corn or soybeans next season is glyphosate at 0.75 to 1.125 pounds acid equivalent per ace (A Roundup product at 22 to 32 fluid ounces per acre) plus 2,4-D ester at 0.5 to 0.75 pounds active ingredient per acre (1.0 to 1.5 pint per acre of a 4.0 pound active ingredient per gallon product).  Using the higher rate range of these products can provide more consistent control of dandelion.  Other products providing similar control include 2,4-D plus dicamba plus metribuzin, Autumn or Autumn Super plus glyphosate or 2,4-D, Canopy EX or DF plus 2,4-D, Basis plus 2,4-D, and simazine plus 2,4-D.  For these combinations apply 2,4-D at 0.75 to 1.0 pounds acid equivalent per acre (1.5 to 2 pints per acre of a 4.0 pound active ingredient product.)  Concerns wtih these programs include cost, options for planting next season's crop, and effectiveness of all species (usually one species is controlled less).  Canopy EX and DF will provide the greatest residual control into next Spring; however, a residual herbicide will still be required next season.

Include ammonium sulfate at 8.5 pounds per 100 gallons of spray mixture for all treatments.  Include crop oil concentrate at 1.5 pints per acre with 2,4-D ester, unless mixed with glyphosate.  When 2,4-D ester is mixed with glyphosate include a nonionic surfactant at 0.25% volume to volume or a quality high surfactant methylated seed oil at 1.0 pt/A.

CREATING AN ENFORCEABLE FARM LEASE

By: Peggy Kirk Hall, Asst. Professor Agricultural & Resource Law, The Ohio State University

A farm lease is a valuable transaction for landowners and farm operators alike, so it is important to ensure that the lease conforms to Ohio’s legal requirements.  Here’s what Ohio law requires for creating a legally enforceable lease:

The lease must be in writing. Enforcing a verbal farm lease is very difficult in Ohio due to our “Statute of Frauds.”  The statute states that a lease of land must be in writing to be legally enforceable in Ohio.  Despite this law, many verbal farm leases do exist.  If a problem arises under a verbal farm lease, the law would not uphold the verbal lease unless a party could prove that the court should grant an exception from the Statute of Frauds writing requirement.  This is a risky position and forces a party to go to court simply to try to prove that there is a valid lease.

The lease must identify the land.  Include the legal description, address and acreage of the land parcel.

Both parties should sign the lease.  Ohio law requires that the landowner must sign the lease, and Ohio’s Statute of Frauds states that a lease agreement is not enforceable against a party who did not sign the lease.  So that the lease is enforceable against both landlord and operator, both should sign the lease.

The lease must properly name the parties and all owners.  Be sure to list all owners, using the proper legal names or business names.  In the case of joint landowners, such as a married couple or partnership, both owners must sign the lease.  If an LLC or similar business entity owns the land, the business entity should be the named party entering into the lease, and the individual who signs the lease on behalf of the entity must have legal authority to do so.

A lease over three years must be acknowledged.  Parties to a lease of more than three years must have their signatures acknowledged and certified by a notary public or local official such as a judge, mayor or clerk of court.

The parties should file a memorandum of lease.  Ohio law requires that the lease transaction be filed with the county recorder in the county where the land exists, which gives notice of the lease arrangement to potential purchasers and others.  Rather than requiring the parties to divulge all details of the lease, the law allows the parties to file a shortened “memorandum of lease” that must include names and addresses of each party, a legal description of the land, the lease period and rights of renewal.

The terms of a farmland lease are also important.