C.O.R.N. Newsletter : 2016-06

  1. What’s Limiting Soybean Yield?---Still Need Data From 185 Fields

    Author(s): Laura Lindsey

    I ran this article last week.  Thank you to all who filled out the survey!  Our goal is to document soybean management practices and yield from 270 soybean fields in Ohio during the 2014 and 2015 growing seasons.  Right now, we are 185 fields short of our goal, but we are continuing to collect data through the month of April. 

    To participate in this research, please see the online survey: https://www.surveymonkey.com/r/ohiosoybean

    With funding from the Ohio Soybean Council and North Central Soybean Research Program, I am embarking on a state-wide project aimed at generating some baseline producer data on current soybean management practices in Ohio’s production systems.  The project goal is to identify key factors that preclude the state soybean producers from obtaining yields that should be potentially possible on their respective individual farms.  The term used for the difference between what yield is possible on your farm each year and what yield you actually achieve is called a “Yield Gap.”

    We are asking crop producers in Ohio to provide us with yield and other agronomic data specific to their soybean production fields. With that data, we could then conduct an in‐depth analysis of what on‐farm factors might be causing a Yield Gap on producer farms. We intend to provide annual reports to all crop producers informing them of what factors we may have identified that, based on our analysis of the data collected from farms, are likely limiting you from achieving soybean yields closer to yield potential that is likely possible on your farms!

    Specifically, we are requesting yield and other data specific to two 2015 fields of soybean and also two 2014 fields of soybeans, that YOU grew on your farm. We recognize that you may best remember the yields and related agronomic data for the 2015 season because you just harvested those fields within the past few months. However, we would very much appreciate additional data in the last two columns of the Survey Form for two 2014 soybean fields on your farm. If you cannot recall or do not have data for any given cell in the columns shown on the Survey Form, leave them blank.

    We look forward to receiving your data. Keep in mind that all data submissions will be kept strictly confidential. In this project, our objective is to WORK FOR YOU. Our goal is to use the data YOU supply to help YOU get soybean yields on YOUR farm fields that, in the future, will be closer to the potential soybean yields that are possible on those fields, once you know what production system factors are holding back YOUR current soybean yields.

    If you have any questions regarding this survey, please feel free to contact me at 614-292-9080 or lindsey.233@osu.edu.

  2. 2016 On-Farm Fertilizer Trials for Corn, Soybean, and Wheat

    Ohio State is looking for farmer cooperators and crop consultants to help conduct on-farm field trials this year. Updating fertilizer recommendations is a major undertaking that will require a collective effort from numerous OSU extension personnel, crop consultants and farmer cooperators. We will be looking specifically at N, P, K and S in corn, soybean and wheat. We hope to collect data from a large number of farms across the state and determine economically-optimum fertilization rates to maximize farmer profitability. These trials should be considered an opportunity to learn more about your farm’s fertility needs, but also contribute to a state-wide effort for better nutrient management and water quality outcomes.

    We can work either directly with farmers, or contract crop consultants and agronomists to conduct the trials and collect data on farmers’ fields. Farmers can choose which nutrient they’d like to work with and will have a large degree of flexibility in the plot layout and applied rates. We have funds to compensate both farmers and crop consultants for their time and effort.

    Phosphorus, Potassium, Sulfur Trials

    Experiments will involve either applying fertilizer or no fertilizer to replicated strip plots. Farmer can decide the rate and source of fertilizer. We are especially interested in fields that test low in P and K.

    Data to be collected:

    ·         Soil sample before planting

    ·         Leaf nutrient analysis at early reproductive stage (R1)

    ·         Grain yields at harvest and nutrient analysis of grain

    ·         Short questionnaire about soil management

    Nitrogen Rate Trials

    A full N rate will be applied in replicated strips (0, 100, 150, 200, 250 lbs N/acre). A zero N treatment is highly desired, but optional. Growers that include a fully replicated zero N treatment will be compensated extra to account for yield loss.

    Data to be collected:

    ·         Soil sample before planting

    ·         Leaf nutrient analysis at early reproductive stage (R1)

    ·         Corn stalk nitrate (optional)

    ·         Grain yields at harvest and nutrient analysis of grain

    ·         Short questionnaire about soil management

    For more information, please see https://osu.app.box.com/s/z877xrhzp9axhutvdekhay9qncuzdczf/1/4768514681/57954041213/1 or contact Steve Culman at culman.2@osu.edu or (330) 822-3787.

  3. It Is Not Too Late to Apply Nitrogen on Wheat

    Streaming nitrogen on wheat

    In many southern Ohio locations wheat has already reached Feekes Growth Stage 5. This is an ideal time to apply spring nitrogen: plants will soon begin a rapid uptake of N and the potential for N loss will be reduced because of this larger demand. The northern part of the state has begun to green-up and N can be applied as soon as fields are fit for equipment.

    Ohio State recommends the Tri-State guide for N rates in wheat. This system relies on yield potential of a field. As a producer, you can greatly increase or reduce your N rate by changing the value for yield potential. Thus, a realistic yield potential is needed to determine the optimum nitrogen rate.  To select a realistic yield potential, look at wheat yield from the past five years.  Throw out the highest and lowest wheat yield, and average the remaining three wheat yields.  This three-year average should reflect the realistic yield potential.

    Table 10 in the Tri State guide recommends 110 lb N for yield goals of 90+; 70 lb for 75 bushels; and 40 lb N for 50 bushel yield goal (these recommendations are for total N and include any fall N). If you prefer to be more specific the following equation may be used for mineral soils, which have both 1 to 5% organic matter and adequate drainage:

    N rate = 40 + [1.75 x (yield potential – 50)]

    We do not give any credit for the previous soybean or cover crop, since we do not know if that organic N source will be released soon enough for the wheat crop. The Tri-state recommends that you subtract from the total (spring N) any fall applied N up to 20 lb/A, whether you deduct fall N depends how much risk you are willing to take and your anticipated return of investment from additional N. Based on the equation above and deducting 20 lb from a fall application, a spring application of 110 lb N per acre would be recommended for a yield potential of 100 bu, 90 for 90 bu potential; 70 for a 80 bu potential and 40 lb N per acre for a 60 bu potential.  Nitrogen rate studies at the Northwest Agricultural Research Station have shown the optimum rate varies depending on the year. However, averaged over years, yield data from these studies correspond well with the recommendation equation given above. These studies have also shown that regardless of the year, yields did not increase above a spring rate of 120 lb N per acre.

    The economic benefit of N stabilizers (especially nitrification inhibitors) diminishes as wheat reaches Feekes Growth Stage 6 since a rapidly growing crop has less risk for N loss. However urea may benefit from a urease inhibitor (products containing NBPT) if conditions for volatilization exist for several days after application. These conditions would include an extended dry period with warm drying temperatures (increases as temperatures go above 70°F) and evaporating winds. Urea applications need at least a 1/2 inch rain within 48 hours to minimize volatilization losses unless temperatures remain relatively cool. The urease inhibitor will prevent volatilization for 10 to 14 days with the anticipation of a significant rainfall event during this time.

  4. Early Termination of Cover Crops

    Cover crops

    Cover crops provide multiple benefits with regards to protecting soil from erosion, improving soil health, and as a component of a nutrient management plan.  For those cover crops that over winter and resume growth in the spring, for example, cereal rye and annual ryegrass, an important question is when to terminate that cover crop.  That decision should consider the next crop, planting date of that next crop, the spring weather pattern and purpose of the cover crop.   For cover crops that have not been planted with the intention of providing a forage harvest, and that are on acres intended for corn grain production, this may be a year to consider early termination of that cover crop.

     A driving factor for early termination of cover crops this year is the potential for a drier than average spring and summer.  On a recent OSU Extension Ag Crops team conference call, Jim Noel from the National Weather Service talked about weather patterns following an El Nino year.  Often the pattern is for the spring and summer months to be drier and warmer than average.  At this point, warmer than average weather and plant growth points to an earlier spring. I have talked with several farmers who tell me that our soil moisture is drier than average.  If this pattern holds, the risk is a cover crop can take up moisture that should be saved for the cash crop.  At the recent conservation tillage conference in Ada I saw data that showed lower corn yields following cover crops in dry years when those cover crops were not terminated early enough.  Those cover crops robbed soil moisture leading to delayed germination and slower development that was not made up compared to a corn crop planted with no cover crops or planted into a winter killed cover crop. 

    Given the risk of or the potential for a drier than average spring and summer, cash grain corn producers should consider terminating cereal grain and annual ryegrass cover crops in the late March to early April time frame.  Ideally we would like to see less than 8 inches of growth for either of those crops.  I have read several sources that recommend annual ryegrass be terminated at 6 inches or less of growth.  The recommended method for early termination is the use of herbicides. 

    Glyphosate should be effective, especially if day time temperatures are above 50 F, and is probably one of the most economical options.  A Purdue Extension publication entitled “Successful Annual Ryegrass Termination with Herbicides” says that producers need to use at least 1.25 lbs. of acid equivalent /acre of glyphosate and possibly up to 2.5 lbs. of acid equivalent /acre of glyphosate under less than ideal conditions for herbicide translocation.  Purdue research also shows that mixing 1 oz. of Sharpen with 1.25 lbs. of acid equivalent rate of glyphosate provides the most consistent results in terminating the cover crop.  Mark Loux, OSU Extension Weed Specialist says that the Sharpen option only needs to be used where there is a desire for burndown help with marestail or other weeds.  The advantage of using Sharpen for this purpose in the tank mix is that it won't reduce the glyphosate activity which can happen with atrazine or 2,4-D in the mix.  Dr. Loux’s recommendation is to use a minimum of 1.5 lbs. of acid equivalent/acre of glyphosate for cover crop termination and only include Sharpen if marestail control is needed.  For those who might be interested, see the April 14th, 2015 (CORN 2015-08) issue of the CORN newsletter by Mark Loux about cover crop burndown.

    For more information about cover crops and termination options talk to a member of the OSU Extension Agronomy Team.

  5. Winter Wheat Progress and Management

    Winter wheat progress 3-7-16

    On March 16 and 17, we visited our wheat trials in Clark County and Pickaway County. Both locations were at Feekes growth stage 5 (leaf sheath erect). In northwest Ohio, wheat is at green-up to Feekes growth stage 4.

    Generally, Feekes growth stage 6 occurs in southern Ohio during early April; however, with abnormally warm temperatures, Feekes growth stage 6 (jointing) may occur sooner. To evaluate wheat for growth stage 6 follow these steps:

    1- Pull, or better yet, dig up, several clusters of tillers with roots and soil from multiple locations in the field;

    2- Identify and select three to four primary tillers from each cluster – usually the largest tillers with the thickest stem, but size can be deceiving;

    3- Strip away and remove all the lower leaves (usually small and yellowish or dead leaves), exposing the base of the stem;

    4- Now look for the first node generally between 1 and 2 inches above the base of the stem. This node is usually seen as a slightly swollen area of a slightly different (darker) shade of green than the rest of the stem.

    For a video on identifying Feekes growth stage 6, see this video:  https://www.youtube.com/watch?v=iukwznx4DPk

    Growth stage 6 signals the beginning of stem elongation. Nitrogen should be applied by this time to maximize yield. This is also the growth stage when some herbicides can no longer be applied. For instance, herbicides such as 2,4-D, Banvel, or MCPA should not be applied after Feekes growth stage 6, as these materials can be translocated into the developing spike, causing sterility or distortion. Huskie and products containing tribenuron and thifensulfuron can be applied through Feekes stage 8, and bromoxynil can be applied until stage 9. Keep in mind that the tribenuron/thifensulfuron-containing products such as Harmony Xtra should generally be mixed with dicamba, 2,4-D or MCPA to broaden the spectrum of control, which affects how late they can be applied. The chart on page 151 of the 2016 Weed Control Guide provides a snapshot of growth stage information.

    You should also begin scouting for early season diseases such as Septoria and powdery mildew. However, we do not recommend foliar fungicide application this early in the season. Although some producers may be interested in tank-mixing foliar fungicides with nitrogen or herbicides, our data shows that under conditions in Ohio fungicide applications at or before jointing do not provide adequate protection of the flag leaf and the heads.

  6. Soybean Cyst Nematode CAN be Done in the Spring

    Soybean cyst nematodes
    Author(s): Anne Dorrance

    These fluctuating temperatures that we have had this spring where we go from snow days to short days provides some opportunities to get the crews out and enjoy some nice weather.  Sampling for Soybean Cyst Nematode is fine to do in the spring, especially in years where the ground thaws early. 

    It is becoming increasingly important in Ohio to know your numbers.  Sounds like a cholesterol warning doesn’t it?  In the case of SCN, less than 500 eggs per cup of soil and keeping it under 1,000 is what we need to shoot for on some fields.  Non-detectable levels are like gold.

    If you haven’t tested in a while, here are some guidelines of fields to be sure to target:

    1.  Fields which are consistently low yielding, always below the county average

    2.  Continuous soybean fields

    3.  Fields with a healthy crop of purple dead nettle, shepherds purse, or planted to a legume cover crop.  These can all serve as additional hosts to SCN and especially with a warm winter there will be some increase in nematode numbers.

    If you have yield maps, especially for no-till farmers, target the low yielding pockets.  SCN will stay in that one pocket, but the pocket will get larger over time with no-till.  With cultivation, the pocket will get larger in the same direction that you till. 

    For a quick video on sampling for SCN check out OSU Dept of Plant Pathology Ph.D. Student Horacio Lopez Nicora’s take on “How to Properly Sample for Soybean Cyst Nematode:  http://plantpath.osu.edu/about-us/multimedia

    Only two labs in Ohio will accept samples:

    Spectrum Analytic Inc

    1087 Jamison Rd NW

    Washington Court House, OH 43160



    740-335-1104 fax



    OSU C. Wayne Ellett Plant and Pest Diagnostic

    Clinic ($15/sample)

    8995 E Main St, Bldg 23

    Reynoldsburg, OH 43068



  7. Temperatures are Still Cool

    These warm days have the engines warming for an early planting but the soil temperatures from around the state are highly variable and still on the cool side.  From the weather stations at the branches, these are the soil temperatures at 2.5 inches, from March 21:


    Research Branch

    Temperature (F)














    Muck Crops






    North Central








    Cool, wet soils promote the growth of one of the major seed and seedling pathogens of corn and soybean, Pythium.  Some of the more than 25 different species of Pythium are particularly favored by these cooler temperatures.  Since the soil is moist, oospores which overwinter, are germinating.  When the soils become saturated, they will form a structure called a sporangium which forms the zoospores.  What is unique about this group of pathogens compared to watermolds is that these spores will then swim to the roots, they are actually attracted to germinating seeds and growing roots.  When seeds are planted into cool soils, and we have some low temperature nights, the seeds themselves can be injured.  This then serves to attract more zoospores – quite a system all in favor of these cool, wet-loving pathogens.

    Plant in as close to optimum conditions as possible.  Don’t try to beat a major storm front – in Ohio that is a classic set up for replant conditions.  Keep monitoring those soil temperatures to ensure the best jump start for this seed.  If in doubt, go back and look at the receipt for that seed, this is a huge investment for the overall farming inputs.  You only want to plant once.

    Well drained soil, and seed treatments with one or more of the following:  metalaxyl/mefenoxam, strobilurin, or the new fungicide ethaboxam will all protect young seeds/seedlings, but to a point.  Too much cold, long periods below 50 F and extensive saturated soils can overwhelm the system.  Resistance to Phytophthora sojae (warmer temperature oomycete) is well studied and well known for all of the varieties that you purchase.  It is not known how resistant the varieties are to Pythium spp.  There are just too many to test.

  8. The Big Data Confusion: Part 3 - Ownership

    This week’s topic in “The Big Data Confusion” series touches on the importance of data ownership.  According to the Privacy and Security Principles for Farm Data, We believe farmers own information generated on their farming operation.  However, it is the responsibility of the farmer to agree upon data use and sharing with other stakeholders that have an economic interest, such as a tenant, landowner, cooperative, agriculture technology provider (ATP), etc.  The farmer contracting with the ATP is responsible for ensuring that only the data they own or have permissions to use is included in the account with the ATP.”  While it seems that the utilization of data from a farm management aspect is a helpful idea, the problem occurs when it’s time to determine who owns that data and who can use it for their own benefit.  According to Farm Bureau, knowing who owns the data is not very straightforward or easy to determine.

    A recent report from the online food and agriculture investment platform, AgFunder, indicated that 2015 agriculture technology investment was $4.6B nearly doubling the $2.4B in 2014. Big data can provide opportunities for farmers and others in agriculture but uncertainty, mostly expressed as skepticism and mistrust, remains at the grassroots level. There is belief that data can be manipulated, sold, and used by others. Big data may significantly affect many aspects of the agricultural industry, but the full extent and nature of its eventual impact remains uncertain.

    It is important for growers to think about how their data can be used and controlled.  From landowner to tenant, to crop sharing, to commercial applicators, many scenarios exist where knowing who owns that data may be unclear. The companies who have signed on to the Privacy and Security Principles for Farm Data document realize how these various scenarios affect farming operations across the country.  Like all other principles highlighted in the Farm Bureau document, the devil is in the details.  By making sure that contracts, leases and agreements are explicit, growers can have a clear understanding of who owns the data; ownership designates control.  However, ownership and access are two different elements of data.

  9. The Latest Weather Outlook


    There are no changes to the weather and climate outlook.

    We expect a rain system March 23-24 with rainfall generally under 1 inch. Another system will pass through about March 27-28 with another 1 inch or less as weather systems remain rather progresssive.

    Precipitation will be close to normal with temperatures above normal the rest of March but only slightly above normal.

    The trend to less wet in April with warmer than normal weather still looks on track.













    4 inch soil






    The latest two week NOAA/NWS/Ohio River Forecast Center rainfall forecast is shown below...


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.


Amanda Bennett (Educator, Agriculture and Natural Resources)
Amanda Douridas (Educator, Agriculture and Natural Resources)
Andy Michel (State Specialist, Entomology)
Anne Dorrance (State Specialist, Soybean Diseases)
Bruce Clevenger, CCA (Educator, Agriculture and Natural Resources)
Dennis Riethman (Educator, Agriculture and Natural Resources)
Glen Arnold, CCA (Field Specialist, Manure Nutrient Management )
Harold Watters, CPAg/CCA (Field Specialist, Agronomic Systems)
Jeff Stachler (Educator, Agriculture and Natural Resources)
Lee Beers, CCA (Educator, Agriculture and Natural Resources)
Les Ober, CCA (Educator, Agriculture and Natural Resources)
Mark Badertscher (Educator, Agriculture and Natural Resources)
Mark Loux (State Specialist, Weed Science)
Mike Gastier, CCA (Educator, Agriculture and Natural Resources)
Pierce Paul (State Specialist, Corn and Wheat Diseases)
Sam Custer (Educator, Agriculture and Natural Resources)
Steve Culman (State Specialist, Soil Fertility)
Ted Wiseman (Educator, Agriculture and Natural Resources)


The information presented here, along with any trade names used, is supplied with the understanding that no discrimination is intended and no endorsement is made by Ohio State University Extension is implied. Although every attempt is made to produce information that is complete, timely, and accurate, the pesticide user bears responsibility of consulting the pesticide label and adhering to those directions.

CFAES provides research and related educational programs to clientele on a nondiscriminatory basis. For more information, visit cfaesdiversity.osu.edu. For an accessible format of this publication, visit cfaes.osu.edu/accessibility.