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Agronomic Crops Network

Ohio State University Extension


C.O.R.N. Newsletter 2011-01

Harold Watters

Top 5 myths of Western Bean Cutworm

 Myth #5: Economic damage from western bean cutworm has occurred in Ohio

To our knowledge, we have yet to see a situation where western bean cutworm control was necessary.  The first larva we found was in Putnam Co in 2009—this was the only one found that year.  In 2010, we did find eggs and larvae in a few counties.  Some of these fields had damaged ears from WBC, but none were at the economic threshold.  Remember, economic threshold is 5% of plants infested with eggs or larvae after inspection of 20 plants in 5 different areas of your field.

So when can Ohio expect economic damage?  Based on situations in our neighboring states and Ontario, it may be soon. Economic damage has been seen in Indiana since 2007, Michigan in 2008 and Ontario since 2010. Typically, some damage was found before economic damage occurred.  This indicates that for Ohio, we could see, or even expect, economic situations within the next few years.  However, because we cannot predict where economic damage will occur, planting Bt hybrids for the sole purpose of WBC control may not provide a good return on investment.  In comparison, adult trapping costs ~$6 for the whole season.  This is a good return on investment considering the valuable scouting information obtained.  Monitoring for adult flight and good egg and larvae scouting remains the best tactic to manage WBC.

IPM in Field Crops

Second, and perhaps more of a long term problem, is that unnecessary applications only increase the likelihood of resistance developing to insecticides.  Some of you might have heard of the term “insecticide treadmill”; this was given to situations where insecticide resistance developed on crops requiring an even greater amount and number of insecticide applications over the years.  A good example is from cotton, where until recently the crop needed 12-15 insecticide applications every year to produce an acceptable yield.  A major cause of this was that an IPM approach was not available nor used in the 1950s and 1960s.  Insecticide resistance has been and continues to be a major concern across the country and throughout the world because it has occurred, is occurring, and will continue to be a potential occurrence.  It should be mentioned that this is a concern with Bt-transgenic traits in corn, but remember, you are already attempting to prevent resistance from occurring by providing refuges whose purpose are to help prevent resistance from developing.  For insecticides, the main way to prevent resistance to insecticides is to NOT use them unless absolutely necessary.

IPM has been and needs to continue to be an extremely important constituent of crop production.  We have made too much progress in managing pests in an economic, effective, environmentally safe, and socially responsible manner to lose effective insecticides by not maintaining an IPM approach to pest management.  In the next C.O.R.N. newsletter, we will discuss how we can use economic injury levels (EILs) and economic thresholds (ETs) in managing our insect pests in an IPM approach. 


Yield or Disease Resistance package – which should come first?

There are lots of things to choose from as we prepare for the 2011 planting season.  Lots of different packages, choices, and we all remember the challenges of the past few field seasons.  In parts of the eastern soybean belt, we have more challenges than most other areas of the midwest soybean production region.  This is a review of the key pathogens in the state that are very well managed with resistance – if the soybean variety has it.

Phytophthora sojae is our number one soil borne pathogen for major portions of the state.  We see it every time the wrong variety is planted and we have heavy rains.  We get stem rot.  When stem rot occurs –  we lose substantial amounts of yield.  For a variety with low levels of partial resistance, we can still lose 50% in yield, and if there is no partial resistance, the whole field can be lost.   In Ohio, where we have poorly drained soils and high proportions of clay  - we have a great diversity of pathotypes or races.  Rps1a is no longer effective against the populations we have in this state.  Rps1c and Rps1k are effective to approximately 30-40% of the populations.  Rps3a is bit higher with approximately 50%.  But this continues to change.  We recovered a few isolates of P. sojae this past summer, where none of the Rps genes were effective, including Rps8.  Within a field there is a great deal of variability so these individual genes may still be effective for some of the isolates but not all.  Therefore for this region, partial resistance becomes the most important part of the Phytophthora resistance package in Ohio.  Partial resistance is known by several different names, tolerance, field resistance – but what you will see is little to no yield loss, the stem rot phase never develops when this is high.    Every company has their own scoring system for partial resistance.  In the Ohio Performance Trials (when I have nontreated seed in time to test) – we use a score of 1 to 9, in which 9 is dead.  Scores of the 3 to 5 represent the best levels for the field.  Other companies use a scoring system where 9 or 10 is best.  So this is one situation to read the fine print.

Soybean Cyst Nematode – for this there are several sources of resistance that each have several genes that are integrated into new varieties.  The interesting thing with this is that not all of the genes get moved into each variety.  Right now there are varieties that have resistance genes from PI88788, Peking and PI 437654 (Hartwig).  PI88788 is the most common.  Based on 3 years of data, the yield drag is no longer an issue here with resistance.  However, like Phytophthora, we do have some SCN populations where some of the PI88788 resistance genes are no longer effective.  If you have SCN and your populations keep increasing, even when you use resistance, it is time to change varieties – for either a different combination of PI88788 genes or Peking or the PI 437654 Hartwig.  The primary key here is don’t plant the same variety – year after year.  If you do have SCN, keep monitoring those populations and rotate to ensure that they stay at levels below 200 eggs/cup of soil, where there is no yield loss.

Sclerotinia stem rot or white mold – for this disease, we had a fairly widespread outbreak in 2009.  So for some fields that were in corn last year, we are moving right back into those fields this next year.  The sclerotia are there, happy as can be.  Resistance to Sclerotinia is challenging, but we have had 2 fairly good years to get rid of the super susceptible varieties.  Again read the company scores for this on whether or not this will be an issue.

Frogeye leaf spot – this foliar disease is more common in the southern US.  We have not had an outbreak in a few years but it is still one to ask about.  This fungus will survive through the winter on residue, for fields where you are planting back-to-back soybeans and you had frogeye there at the end of the season – it really needs a resistant line, better yet plant corn. 

Brown Stem Rot – we have this here in Ohio, but it does not seem to cause the same level of disease as what they find in Northern Illinois and Wisconsin.  Symptom development is related to low pH.  For areas where the pH is 6 or below, choosing varieties with this resistance package is important.

SDS – a lot of work has gone into this one over the past few years.  For soils that have SCN, compacted soil conditions and otherwise poor drainage, add this pathogen to the list.  We have seen several situations where the SDS symptoms occurred right to the row where the varieties switched out.  Based on surveys from myself, county educators, and crop consultants comments; I think this is now throughout the state.  This is another one that is difficult to screen, but Southern Illinois does a lot of testing and on their website they have some good information on resistance levels in some varieties.

Excellent yields are key to making profits – but without disease resistance, there will be big losses if the environment turns favorable for the pathogens – don’t forget this part of the total package as you work with your seed dealers.


2010 Northwest Ohio Corn Silage Test

The plots were planted with 4 row air type planters and maintained by each respective state utilizing standard production practices. The center 2 rows were harvested with MSU’s self-propelled forage harvester. Silage tests were harvested uniformly as close to half milk line as possible. Near Infrared Reflectance (NIR) Quality Analysis was performed by MSU using their current procedures. Silage results present the percent dry matter of each hybrid plus green weight and dry weight as tons per acre. Other data presented include percent stand, the percentage of in vitro digestible dry matter, acid detergent fiber, neutral detergent fiber, crude protein and starch. An updated calculation using the MILK2006 equation (UW-Madison Dairy Science Department) was used to estimate milk per ton and milk per acre. 

A complete summary of the Ohio results is available online at: More information on procedures and additional 2010 MSU silage test data can be viewed on the web at For more information on Ohio States crop variety testing, visit:


Conservation Tillage Conference Registration Open

The Conservation Tillage & Technology Conference will be held on the 24th and 25th of February 2011 at Ohio Northern University McIntosh Center in Ada, Ohio. Topics offered this year, registration form, and related information can be viewed at the highlighted site below. or      

New this year, either PayPal, credit card or check can be used for registration fees.

If you have any questions about the registration, please feel free to contact Albert Suniga,, Allen Soil & Water Conservation District Phone: 419.223.0040 x109 ( For questions about the program topics, please contact Gary Wilson at 419.422.3851 or send email to


Check our blogs

A new blog has been added to the Agronomic Crops Team webpage:, this blog will emphasize Crop Production for Profit. Check all of our blogs for local updates across Ohio to supplement the C.O.R.N. newsletter and the Team webpage.


Certified Crop Adviser (CCA) Exam Training Session

This training session is designed to help participants understand the agronomic principles necessary to become a certified crop advisor and to assist in preparation for the state and international CCA exams. 

To register contact:

Wesley Haun, OSU Extension, Logan County

120 E. Sandusky Ave.  Suite #1

Bellefontaine OH 43311. 

For more information please contact Wes Haun at


Winter Months are Learning Months

Please check our Agronomic Crops Team Calendar ( for these January events:


January 18

Conservation Tillage Breakfast Meetings

Plaza Inn, 491 S. Main St., Mt. Victory, Ohio

Program is Cost Effective Herbicide Management, with Dr. Mark Loux with breakfast at 7:30 am program at 8:00 am.


January 19 & 20

Certified Crop Adviser (CCA) Exam Training Session

Shelby County Extension Office, 810 Fair Road, Sidney, OH


January 25

Preserving Corn & Soybean Profits with Agronomy Updates

Crawford County Court House, 112 East Mansfield St., Bucyrus, OH


January 26

Agronomy Day-Paulding County

Paulding County Extension Center, Paulding, OH

Farm Programs, crop insurance, weed control, wheat disease and fertility.


January 27

Corn/Soybean Day

Founder’s Hall at Sauder Village 22611 St. Rt. 2 Archbold, Ohio

Insect to be on the lookout for in 2011, Managing Wheat for Yield and Quality, What is going on with the Weather and What to expect for 2011, and Risk and Reward in Nutrient Management plus CCA and Pesticide Applicator credits.


January 27

Agronomy Night-Putnam County

Kalida K of C Hall. Kalida, OH

Topics for the program include Managing Wheat for Yield and Quality, Risk and Reward in Nutrient Management, Managing Resistant Weeds, Results of the Cereal Rye and Oilseed Radish Cover Crop Plots


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Crop Observation and Recommendation Network

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.