C.O.R.N. Newsletter 2005-13

Dates Covered: 
May 16, 2005 - May 24, 2005
Editor: 
Tammy Dobbels

Corn Emergence Problems and Replant Decisions

Authors: Patrick Lipps, Peter Thomison

The rains over the weekend have promoted corn emergence in fields with surface crusting problems and have probably reduced the need to replant many fields. Nevertheless, replanting is expected to be extensive in parts of Ohio, with perhaps as much as 30 to 50% of some counties’ corn acreage affected, especially in northern Ohio.
Before finalizing replant plans, growers need to scout their corn fields and dig up seedlings to evaluate their condition. Some fields that were crusted over and exhibiting corn leafing out under ground last week may be showing signs of recovery following rotary hoeing and the weekend’s rain. Other fields may also appear to be recovering with seedling shoots visible above ground. However, close examination of such seedlings may reveal that seeds and roots are rotting, showing seedling blight symptoms, and likely to result in seedling death.

More on assessing corn emergence problems and making replant decisions is available in the following C.O.R. N. newsletter articles (http://corn.osu.edu/archive/)

“Assessing Corn Seedling Emergence and Seedling Diseases” (Pat Lipps) and “Check Corn Fields for Emergence Problems” (Peter Thomison) C.O.R.N. Newsletter 2005-12, May 9-17, 2005.

“Corn Replanting Considerations” (Peter Thomison) C.O.R.N. Newsletter 2005-11, May 3-10, 2005.

Reports of the corn seedling emergence problem indicate that the worst fields were planted on or after April 15. During this time, the soil was relatively dry and soil temperatures were increasing to the mid 60 degree F range. On April 20 cold rains started that lasted until April 25. Over this 5 day period soil temperatures dropped from 60 degrees F to about 40 degrees F at most locations in the state. Cool temperatures during the last week of April kept soil temperatures below 60 degrees F until about May 3. Therefore, germinated seedlings and seeds were under persistent cold and wet conditions for at least two weeks in most locations.

Damage from cold temperature stress adversely affected the germination of seeds and the growth of young seedlings and probably predisposed the plants to invasion by soil fungi capable of causing seed rot and seedling blight. In addition to slowing the germination process, cold temperatures, snow and freezing rain from April 20-25 may have caused irreparable harm to the delicate structures of emerging corn seedling. When dry corn seed absorbs cold water as a result of a cold rain or melting snow, “imbibitional chilling injury” may result. Cold water can cause similar injury to seedling structures as they emerge during germination. Such injury in corn seed ruptures cell membranes and results in aborted radicles, proliferation of seminal roots, and delayed seedling growth. When temperatures remain at or below 50 degree F after planting (as they did this year for two weeks) damage to germinating seed is particularly severe. Many of the corn seed planted shortly before the cold temperature stress of April 20-25 have produced seedlings exhibiting symptoms which are characteristic of imbibitional chilling injury (e.g. stunted or aborted radicles).When this physiological damage is combined with surface soil crusting, saturated soil conditions, compacted soils, deep seed placement, and seedling blights, you have a recipe for widespread emergence problems.

“Patching in” Corn and Uneven Emergence

Authors: Peter Thomison

In many Ohio corn fields, poor emergence has resulted in plant stands that are inadequate for optimum grain yields. Moreover, the remaining plants in affected fields are usually unevenly spaced within rows and not developing uniformly. Questions often arise as to whether to patch-in these poor stands, replant stands with poor emergence, or to protect late emerging plants during row cultivation. The following are some guidelines to consider in these situations based on findings of Illinois and Wisconsin research. More information on this subject is available in National Corn Handbook Chapter 36, "Effects of Uneven Seedling Emergence in Corn" http://www.ces.purdue.edu/extmedia/NCH/NCH-36.html

WHEN SHOULD YOU PATCH-IN A POOR STAND?
Growers will sometimes attempt to plant over or "patch in" a poor stand rather than kill the existing plants and replant at a full population. However, "patching in" is generally of limited benefit unless the surviving plant population is less than one half that of the original. The success of such an approach is even less likely late in the planting season (i.e. after June 1). Later planted corn cannot compete effectively with the remnants of the original plant population for sunlight, water, and nutrients. In these late planting situations, late emerging plants often function more like weeds, and contribute little to grain yield.

If you replant within 2 weeks of planting the original, patching-in may be a viable option. Yields will be similar to those from a uniform-emerging replanted stand, if you can get relatively uniform plant spacing within the row between the old and new plants. However, within 2 weeks of planting, it probably will be too early to determine what the final stand will be (and whether patching will be needed).

If you replant within 3 weeks after the initial planting, yield potential is about 10% greater if you tear up the field and start over with an even emerging stand rather than just patch-in the original stand. Balance this possible yield increase against the additional cost of tillage, seed, and dryer fuel.

SHOULD YOU REPLANT STANDS WITH UNEVEN EMERGENCE?
If the delay in emergence is less than 2 weeks, replanting will have a minimal effect on yields, regardless of the pattern of unevenness.

If one half or more of the plants in the stand emerge 3 weeks late or later, then replanting may increase yields by up to 10%. To decide whether to replant in this situation, estimate both the expected economic return of the increased yield compared to your replanting costs and the risk of emergence problems with the replanted stand.
For more information on replanting corn, check the C.O.R.N Newsletter of May 3-10, 2005 "Corn Replanting Considerations) available on-line at http://corn.osu.edu/archive/

SHOULD LATE EMERGING PLANTS BE PROTECTED DURING ROW CULTIVATION?
If the delayed plants emerge only 1 to 2 weeks late, use shields and avoid burying the late-emergers during cultivation.

Protect plants emerging 3 weeks late if one half or more of the plants in the stand are late-emergers.

If less than 1/4 of the stand emerges 3 weeks late or later, it probably will not pay to encourage their survival. Yields will be about the same whether or not these delayed plants are buried during cultivation.

Replant Considerations: Hybrid Selection Issues

Authors: Peter Thomison

Is It Time To Switch To Earlier Maturing Corn Hybrids?
Is there a need to switch from full season to shorter season hybrids for replanting? Probably not - in most situations full season hybrids will perform satisfactorily
(i.e.,will achieve physiological maturity or "black layer" before a killing frost) even when planted as late as May 20, if not later in some regions of the state.

Results of studies evaluating hybrid response to delayed planting dates indicate that hybrids of varying maturity can "adjust" their growth and development in response to a shortened growing season. A hybrid planted in late May will mature at a faster thermal rate (i.e. require fewer heat units) than the same hybrid planted in late April or early May). In Ohio and Indiana, we've observed decreases in required heat units from planting to kernel black layer which average about 6.8 growing degree days (GDDs) per day of delayed planting. Therefore a hybrid rated at 2800 GDDs with normal planting dates (i.e. late April or early May) may require slightly less than 2600 GDDs when planted in late May or early June, i.e. a 30 day delay in planting may result in a hybrid maturing in 204 fewer GDDs (30 days multiplied by 6.8 GDDs per day).

There are other factors concerning hybrid maturity, however, that need to be considered. Although a full season hybrid may still have a yield advantage over shorter season hybrids planted in late May, it could have significantly higher grain moisture at maturity than earlier maturing hybrids if it dries down slowly. Moreover, there are many short to mid season hybrids with excellent yield potential. Therefore if you think you may end up planting in late May consider the dry down characteristics of your various hybrids. In past years, some mid to full season hybrids had grain moisture levels at harvest similar to those of short season hybrids because of rapid dry down rates. Keep this in mind before you trade the hybrids you originally planned to use for shorter season
alternatives.

If replanting is delayed beyond next week, growers in parts of northeast and north central Ohio may want to consider corn hybrids that require 100 to 150 fewer GDD than the adapted full season hybrids usually planted. These areas of the state historically accumulate fewer GDDs during the growing season than other regions of Ohio.

For more detailed information on selecting corn hybrids for delayed planting in different parts of Ohio consult "Delayed Planting & Hybrid Maturity Decisions" OSUE Bull. 902
available online at http://ohioline.osu.edu/b902/b902.pdf.

Other hybrid selection - replant considerations:
Later planting dates increase the possibility of damage from European corn borer (ECB) and may warrant selection of ECB Bt hybrids if suitable maturities are available.
Results of research at Ohio State and other universities indicate a significant yield advantage of Bt corns over their conventional non Bt counterparts when planted in late May and early June. Moreover, the yield advantages of Bt corn hybrids over conventional (non-Bt) hybrids are more consistent for late planting dates compared with normal dates.

Planting a herbicide tolerant corn, i.e. Roundup Ready, Liberty Link, or Clearfield, may help expedite the replant process. Once the replanted herbicide tolerant corn has emerged, what remains of the previous corn stand can be killed with the appropriate herbicide (as long as the corn used in the original planting was not a hybrid tolerant to that herbicide).

Seeding Rates & Replanting Corn

Authors: Peter Thomison

Corn seeding rates should not be changed much for replanted corn. Soil temperatures for corn planted in late May or early June will be quite warm relative to that of usual late April or early May plantings. Couple that with the likely ample availability of soil moisture and the odds are that germination and emergence success will be greater than normal. Consequently, you may choose to reduce your seeding rate accordingly. Instead of planting 33,300 seeds to achieve 30,000 plants (90% success rate), you may elect to plant only 30,600 seeds per acre (98% success rate).

For more information on this topic, see the article "Late-Planted Corn & Seeding Rates" in the 2002-13 issue of C.O.R.N., May 13-20, 2002. (http://corn.osu.edu/archive/2002/may/02-13.html#linkc)

Weed Management in Replanted Corn Fields

Authors: Mark Loux

We have received numerous questions about weed control and herbicide use in corn fields that are being replanted. Some points to consider on this issue:

- Where it is necessary to kill the previous corn stand, an application of glyphosate may be the most economical and effective means of doing so (as long as the corn is not Roundup Ready – see recent C.O.R.N. articles on control of Roundup Ready corn). This can be accomplished with 0.38 lbs of glyphosate (11 to 16 oz of product, depending upon the formulation).
- Do not use postemergence grass herbicides (Select, Assure II, Fusion, etc) to kill existing corn stands, since these herbicides have sufficient soil residual to injure corn that is replanted in the field.
- Where the field has already been treated with preemergence corn herbicides, try to avoid further tillage. Preemergence herbicides in most areas have already received enough rain to ensure a uniform distribution in the upper few inches of soil. At this point, tillage probably won’t improve the distribution, and it can cause less uniform herbicide distribution at the same time that it stimulates a new flush of weeds. Where the field will be tilled, try to disturb only the upper two inches on soil to prevent further dilution of herbicide.
- It is fairly difficult to predict whether preemergence herbicides applied in mid-April will control weeds until replanted corn develops a crop canopy. This is most likely to occur where preemergence herbicides were applied after the wet, cold period that occurred at the end of April. We recommend scouting fields within 2 to 3 weeks after planting and applying postemergence herbicides as necessary. The good news is that corn planted in mid-May tends to grow faster than corn planted in April, and probably only needs about 4 weeks of additional weed control. So, scouting fields early can allow application of relatively low rates of herbicide when weeds are small, with less likelihood that a lot of weeds will emerge after postemergence application. Stated another way – the major period of weed emergence is late April through early June, and later planted crops therefore require a shorter period of weed control (this depends upon the amount of mid-season rain and the amount of weed seed in the seedbank, of course).
- Another option in replanted fields that received preemergence herbicides in April is to apply additional amounts of preemergence herbicide now to ensure a long enough period of weed control. We prefer the approach outlined above, scouting and postemergence herbicides, because it is impossible to know how much herbicide has been lost already. Where additional preemergence herbicide is applied, be sure not to exceed the maximum rate that can be applied per year for a given product (i.e. if you already applied atrazine premix X, be sure to check the label to see how much more of herbicide X can be applied the same year).
- Where the replanted field has not already been treated with preemergence herbicides, a number of herbicide programs can be used. Preemergence herbicides can be applied to the replanted field, and this may be the best option for producers who have already purchased preemergence herbicides that need to be used this season. However, a total postmergence herbicide program can be a viable option in later-planted fields. The two concerns that we have about total postemergence herbicide programs (the ones without much residual that are usually applied when weeds are at least 3 inches tall) in corn are: 1) they should be applied before most of the annual weeds in the field exceed about 4 inches in height to avoid yield loss due to interference with the crop; and 2) postemergence programs without much residual activity may not control later-emerging weeds, which are less likely to reduce yield but can still interfere with harvest and produce seed. The first of these is an issue in any corn field, regardless of planting date. The second is more of an issue in early-planted corn, which can grow fairly slowly and is subject to 6 to 10 weeks of weed emergence. Corn planted in mid-May should grow faster and become competitive with weeds sooner than early planted corn, and it is subject to a shorter period of weed emergence. So, many postemergence programs with limited residual activity may have more utility as corn is planted later. Postemergence herbicides are not necessarily more effective than preemergence herbicides on summer annual weeds, but they can be considerably more effective on giant ragweed, cocklebur, burcucumber, and perennial weeds that tend to be a problem in mid to late season.
- A number of factors should be taken into account when deciding whether to use preemergence or postemergence herbicides at this time of the year, including: whether preemergence herbicides have already been purchased and need to be used this season; cost of herbicides/application; which approach is likely to be most effective on the weed species in the field; and the time available to make postemergence herbicide applications in corn. The latter factor is no minor one, given that most producers are treating almost 100% of their soybeans with postemergence herbicides. Even in replanted corn, we are reluctant to recommend total postemergence herbicide programs in fields that have moderate to high weed populations, if there is some doubt that the postemergence application will be made in a timely manner.

Corn Replanting and Fertilizer Issues

Authors: Robert Mullen

How should our fertility management change this year considering the amount of replanting that may occur? This is a frequent question being asked this year. In the following article, we will cover many of the issues that may be of concern.

If I applied starter with my initial planting, should I be careful to avoid seeding directly into the fertilizer band?
If you do have to replant and you applied some starter material at the time of your first planting, you should not be too concerned with planting directly in the fertilizer row. At this point the salt concentration should have dissipated enough that it should not result in seed injury or delayed emergence. Even if urea based fertilizers were applied with the starter, the ammonia saturation zone should have dissipated enough that it will not cause problems.

When replanting should I consider using a starter fertilizer?
There are a couple of things to consider. If soil phosphorus (P) and potassium (K) are extremely high, then inclusion of those two nutrients is not likely to result in increased yields. The likelihood of seeing a response to starter P and K decreases as soil temperatures increase, so supplying these nutrients in a soil environment already nutrient rich will not likely affect plant growth or yield. If soil test levels are near or below the established critical levels (see the Tri-State Fertilizer Recommendations - (http://ohioline.osu.edu/e2567/index.html) inclusion of starter may be beneficial. Late planted corn can benefit from starter material, especially if soil nutrient levels are relatively low. Relative maturity of the corn hybrid should also be considered when deciding whether or not to include starter fertilizer. Longer season hybrids that are planted late are more likely to benefit from application of starter material than shorter season hybrids that are planted late. Utilize the same guidelines when applying starter materials. Do not apply more than 100 lbs of nitrogen plus K2O in the starter band (applied 2 x 2). If using a liquid pop-up material, do not apply more than 8 lbs of nitrogen plus K2O with the seed. Liquid pop-up materials do not perform as consistently as 2 x 2 applied starters, primarily due to the low amounts of fertilizer that can be applied. Twenty pounds of starter nitrogen should be sufficient to supply the crop with adequate nitrogen.

Should I assume that I have lost some N that was applied earlier this year and apply more than I typically do to account for this loss?
If anhydrous ammonia was applied back in mid-April, I would not assume that much has been lost. Depending upon your specific field conditions some may have been lost, but the amount should be minimal considering our general weather patterns this spring. Spring applied urea-ammonium nitrate (UAN) may have been susceptible to leaching losses (the nitrate fraction specifically) on coarser textured soils, so at least be aware that some of that material may not be around. Will you need to replace that which was lost? If you were already planning on sidedressing those fields, I would not be overly concerned with replacing what was lost unless your preplant amounts were low and you are planning on applying very little sidedress. This spring has not been too bad when it comes to losses of nitrogen (with the exception of nitrate-nitrogen on coarse textured soils), but it does depend upon your specific field environment.

Should I cut back on my nitrogen rates to account for my decrease in yield potential?
The later you get your corn in the ground the less likely you are to produce that bumper crop, so do not apply a lot of nitrogen in hopes of producing it. Select your nitrogen rates based on your realistic yield goal at this point (which should be a little lower than three weeks ago). Production fields that get fall applied manure can be evaluated using the presidedress soil nitrate test (PSNT) to aid in making your sidedress nitrogen decisions. Nitrate levels greater than 30 ppm (60 lb/acre) are not likely to benefit from additional nitrogen.

Seed Treatments are Especially Important for Phytophthora sojae Now!

Authors: Anne Dorrance

The soils have been wet in Ohio now for several weeks, while cool, these conditions have favored oospore germination of the oomycete, Phytophthora sojae. Oospores are the overwintering stage and they require at least 2 weeks of moist conditions for germination. Once soybeans are planted and the soils re-flooded there will be inoculum there to favor seed and seedling blights caused by this and other soil-borne pathogens. For those in areas of Ohio where Phytophthora is mainly responsible for stand loss, use the highest rates of either Allegiance (metalaxyl, 1.5 fl oz/cwt) or Apron XL, (mefenoxam, 0.64 fl oz/cwt). Note we have found some seed companies giving the rate per 50# bag of seed the rate would then be 0.75 fl oz of Allegiance and 0.32 fl oz of Apron XL. Based on both greenhouse and field studies, when soils are flooded a few days after planting, the highest rate is required for the best protection.

Wheat Powdery Mildew Now And Head Scab Risk Evaluation Soon

Authors: Patrick Lipps

Wheat is growing very rapidly with the mild weather. Wheat in southern Ohio is beginning to head (Feekes' growth stage 10.1) and in northern Ohio the wheat is in the boot stage (Feekes growth stage 10). Cool moist temperatures during this time will cause rapid increase in powdery mildew on susceptible wheat varieties. Varieties to check for the development of powdery mildew include: AGI 202, AgriPro Cooper, Pioneer 25R49, Pioneer 25R74, Certified Bravo, Seed Consultants SC1335, Seed Consultants SC1342, Seed Consultants SC1325, Steyer's Hartman, and Wellman W120. There are likely other varieties that should be checked for disease as well. Powdery mildew may not be present in all fields of these varieties because crop rotation and weather effects may have cause variation in disease development. However, it always pays to check. Make the decision to apply a fungicide if powdery mildew is easily detected in the lower canopy and the leaf below the flag leaf is in danger of becoming infected. Check about 50 tillers throughout the field to see if the disease is wide spread in the field. Tilt and PropiMax are the better fungicides for control of powdery mildew but Headline, Quilt and Stratego also give effective control. Most of these materials will give about three weeks of powdery mildew control and also protect against some of the other leaf diseases.

Now that wheat is beginning to head in southern Ohio and it will be flowering in about 4 to 5 days, we need to begin to pay attention to the risk of head scab in the crop. The occurrence of head scab is highly dependent on weather conditions that occur from about a week prior to flowering through flowering. The risk of having the disease can be predicted based on the weather conditions that occur during this time. In last week's C.O.R.N. newsletter I gave an introduction to the Fusarium Head Blight Prediction Center that is available for public use at http://www.wheatscab.psu.edu/ and its use. Please visit this web site after your wheat is in head and you see the first anthers on the heads indicating that it is flowering. This web site will indicate if the weather conditions have been conducive for head scab development up to the time of flowering. No predictions are made for time periods after flowering at this time, but in future years we may be able to do this. Up until today (May 16) the risk of having head scab has been predicted to be low due to the cooler temperatures that have occurred over the past few days except for fields that have been planted into corn stubble. We will watch predictions for head scab, especially for the southern part of the state later this week and for the northern part of the state over the next two weeks. Hopefully, drier, cool weather will limit its activity this year. We will keep you informed of the risks in the next few newsletters.

Insect Update

Authors: Ron Hammond, Bruce Eisley

European Corn Borer – Because of the likelihood of significant corn replanting, we might see an increase in European corn borer injury because late planting can lead to corn borer problems. Growers might consider planting an ECB Bt hybrid if available. Growers should read the article “Replant Considerations: Hybrid Selection Issues” in this issue of the CORN newsletter for more information on this and other concerns related to the replanting of corn.

Corn Flea Beetle – We have recently received a few reports of flea beetles beginning to feed on young corn plants. Flea beetles are very small beetles, about 1/8 inch in size. Flea beetles do not usually cause significant damage unless in heavy populations; however, they can transmit Stewart’s wilt disease. Based on the corn flea beetle index that was reported in newsletter 5 (http://corn.osu.edu/index.php?setissueID=70) we did not anticipate much activity from the corn flea beetle this year because of the cold winter. However, based on these reports being received, survival may have been better than anticipated. Based on this new information, it will be wise to start scouting corn fields as soon as they emerge for corn flea beetle and then apply treatments according to population levels that are found. Rescue treatment is warranted if plants begin to wilt and a potential loss in stand appears likely.

Alfalfa Weevil – There have been relatively few reports of alfalfa weevil causing injury to alfalfa so far this spring, which suggests that perhaps Ohio alfalfa producers have escaped major problems. However, there are those isolated fields where the weevil has built up to damaging levels, especially on hills facing the south. At this time, most alfalfa fields are getting closer to harvest, with most growth at least over 20 inches in height. Thus, if any fields have weevils causing damage, growers should consider early harvesting as the most appropriate management tactic. Following harvest, growers should monitor regrowth for potential problems.

Slugs – Slugs are continuing to hatch in no-till field crops throughout Ohio, with most fields in east central Ohio having juvenile slug populations, while fields in the north are just now seeing the hatch beginning. Growers with a past history of slug problems should begin scouting their fields over the next 2 weeks as crops emerge for beginning injury. Additionally, those no-till growers who have to replant either corn or soybean should pay close attention to their situation because they will have a crop germinating and emerging while the slugs are actively feeding.

Bean Leaf Beetle – Although reports of bean leaf beetles in soybeans have not yet been received, we have been seeing a number of beetles that appear to be overwintering in soybean residue while searching for slugs and other soil insects. As with corn flea beetle in corn and slugs in corn and soybean, growers should also monitor for bean leaf beetle populations in soybeans over the next 2-4 weeks.

Strategies to Reduced Spray Drift

Authors: Erdal Ozkan

Spray drift is one of the most serious problems pesticide applicators have to deal with. Three-fourths of the agriculture-related complaints investigated by the Ohio Department of Agriculture involve drift. In a five-year period two-thirds of the total complaints in Iowa were related to drift. A major insurance company reported about a third of the court cases related to spray misapplication involved drift. Spray drift occurs wherever liquid sprays are applied. Eliminating drift completely is impossible. However, it can be reduced to a minimum if chemicals are applied with good judgment and proper selection and operation of application equipment.
Major factors that influence drift are: spray characteristics, equipment/application techniques, weather conditions, and operator skill and care. Spraying under excessive wind conditions is always the most common reason why applicators get sued for creating drift.
After wind speed, spray droplet size is by far the most important factor affecting drift. Research has shown that there is a rapid decrease in the drift potential of droplets whose diameters are greater than approximately 200 microns (about twice the thickness of human hair). If operators of sprayers pay attention to wind direction and velocity, and have knowledge of droplet sizes produced by different nozzles, drift can be minimized.
Here is a list of other drift reduction strategies which one can adopt to keep drift under control:

1. Use nozzles that produce coarser droplets when applying pesticides on targets that do not require small, uniformly distributed droplets (such as systemic products, pre-plant soil incorporated applications, fertilizer applications).
2. Keep spray volume up, and use nozzles with larger orifices.
3. Follow recent changes in equipment and technology such as shields, air-assisted and electrostatic sprayers that are developed for drift reduction in mind. Adopt some of these technologies when you feel it is time to do so.
4. Keep the boom closer to the spray target. Nozzles with wider spray angle will allow you to do that.
5. Keep spray pressure down, and make sure pressure gauges are accurate.
6. Follow label recommendations to avoid drift with highly volatile pesticides.
7. If you are not using low-drift nozzles, try adding Drift Retardant Adjuvants into your spray mixture.
8. Avoid spraying on extremely hot, dry and windy days, especially if sensitive vegetation is nearby. Try spraying in mornings and late afternoons. Although it may not be practical, from the drift reduction aspect, the best time to spray is at night.
9. Avoid spraying near sensitive crops that are downwind. Leave a buffer strip of 50 to 100 feet, and spray the strip later when the wind shifts.
10. Good judgment can mean the difference between an efficient, economical application, or one that results in drift, damaging non-target crops and creating environmental pollution. If there is any doubt about a spraying job that might result in drift, one should wait until there is no longer that element of doubt.

Archive Issue Contributors: 

State Specialists: Pat Lipps, Anne Dorrance and Dennis Mills (Plant Pathology), Robert Mullen (Soil Fertility), Bruce Eisley & Ron Hammond (Entomology), Mark Loux and Jeff Stachler (Weed Science), Peter Thomison (Crop Science-Corn), Erdal Ozkan (Ag Engineering). Extension Educators: Roger Bender (Shelby), Steve Foster (Darke), Gary Wilson (Hancock), Dusty Sonnenberg (Henry), Howard Siegrist (Licking), Harold Watters (Champaign), Tammy Dobbels (Logan), Glenn Arnold (Putnam), Greg LaBarge (Fulton), Mark Koenig (Sandusky), Todd Mangen (Mercer), Ed Lentz (Seneca), Allen Sundermeier (Wood), Steve Bartels (Hamilton), & Bruce Clevenger (Defiance)

About the C.O.R.N. Newsletter

C.O.R.N. Newsletter is a summary of crop observations, related information, and appropriate recommendations for Ohio crop producers and industry. C.O.R.N. Newsletter is produced by the Ohio State University Extension Agronomy Team, state specialists at The Ohio State University and the Ohio Agricultural Research and Development Center (OARDC). C.O.R.N. Newsletter questions are directed to Extension and OARDC state specialists and associates at Ohio State.