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Agronomic Crops Network

Ohio State University Extension


C.O.R.N. Newsletter 2005-04

Dates Covered: 
February 22, 2005 - March 8, 2005
Harold Watters

Wheat Condition Update: Be Prepared for Off Colored Wheat

Authors: Patrick Lipps

This is just a reminder to all the wheat growers in Ohio that the next two to three weeks marks the time of year when stand losses usually occur. The last week of February and the first two weeks of March usually has weather that favors multiple cycles of freezing and thawing. Freezing and thawing causes heaving, where the crowns and roots of wheat plants are pushed up and out of the ground. These plants generally do not show stress until the temperatures warm and they begin to grow. By about mid March, growers begin to see these plants turn color and report that the wheat is 'going backwards'. This is because it generally takes several weeks for the heaved plants to show water stress and die. We have had some very cold temperatures and a lot of water on the fields over the past two months. The wheat will likely have a difficult time starting to re-grow this spring except in fields that are very well drained. Hopefully some nitrogen was applied in the fall at planting (20 to 30 lb N/A recommended) and the wheat seed was planted at 1.5 inches deep. Planting at the proper depth will help against heaving and the nitrogen applied last fall will supply adequate nutrition as the plants begin to re-grow this spring. Remember that the wheat plant must produce a completely new root system in the spring and until these new roots are developed little nutrition is taken up by the plant. It is during the time when the plants begin to re-grow and new roots become functional that the wheat looks its worse. Given time, warmer weather and better drainage, the wheat will begin to improve in condition. Hopefully, the weather will cooperate and the new crop will emerge from the grips of winter in reasonable condition. We will provide information on determining adequate stands of wheat in a newsletter article later as the crop begins to green up. Until then, watch the wheat fields in your area and note any fields that are not 'greening-up' as expected.

Gypsum Application and Crop Production

Authors: Robert Mullen

When considering what to do this coming growing season, some may be thinking about gypsum application to improve crop production. So what does gypsum contain that can improve crop productivity?

Sulfur (S) - Gypsum is a good source of sulfur containing about 18% S. For corn production in Ohio, sulfur deficiencies have not been well documented. However, due to greater environmental regulation less S is being deposited with rainfall, so the potential does exist for some S deficiencies to be observed. Most S deficiencies occur on sandy, low organic matter soils. If a S deficiency is suspected, tissue testing can be used to confirm it. Soybeans have a lower S demand, and S deficiency is less likely to occur in a soybean crop. Alfalfa responses to S have been found, but yield increases have not been consistent. If applying gypsum to meet crop S needs, rates are typically between 100 and 300 lb gypsum/acre (18 to 54 lb S/acre).

Calcium (Ca) - Gypsum is also a good source of Ca (23%). Most of the soils across the state contain large amounts of exchangeable Ca (especially in the western half of the state). It is common for a soil to contain around 3,000 to 5,000 lb of exchangeable Ca. So as far as needing fertilizer Ca, it is usually not necessary. It has been proposed that an “optimum” ratio of Ca to magnesium (Mg) and Mg to potassium (K) exists to improve crop production. McLean (a former researcher at OSU) conducted extensive work evaluating this concept and found no relationship between the Ca:Mg ratio or Mg:K ratio and crop yield (he conducted this on several crops including corn, soybeans, wheat, and alfalfa). Similar work conducted in Wisconsin shows that “optimum” ratios do not result in improved crop productivity.

Application of Ca (from gypsum) can be used to improve (or ameliorate) subsoil acidity. This is most likely specific to the eastern half of the state where acid subsoils occur with greater frequency. Remember gypsum is not a liming material. The Ca applied displaces the subsoil aluminum on the cation exchange sites and decreases the toxicity of subsoil aluminum. This does not necessarily increase subsoil pH, but small increases in subsoil pH have been reported. Research of this concept and practice has been conducted primarily in the southeastern U.S.

Ultimately, you the producers are the ones responsible for what goes into your crop production system. Considering the data available and what we know about nutrient dynamics in the soil, the university does not currently recommend application of gypsum to improve crop productivity.

Historical Ohio Corn Performance Test Data Now Available

Authors: Allen Geyer, Peter Thomison, Rich Minyo

The Ohio Corn Performance Test as it is known today was started in 1972 as an independent third party test to assist producers in selecting corn hybrids to be grown on their farms. The results were initially distributed as a stand-alone publication until 1995, when they were first printed in Ohio’s Country Journal. In 2004, 20,000 copies were distributed to subscribers of Ohio’s Country Journal, with an additional 10,000 copies distributed to county extension offices and at various producer meetings.

In 1972, there were 4 sites with an average yield of 144.6 bushels per acre. Data was collected on yield, % harvest moisture, % stalk lodging, % root lodging and % emergence. In 2004, there were 11 sites with an average of 188.7 bushels per acre. Data is currently collected on final stand, yield, % harvest moisture, % stalk lodging, % emergence, silking date and test weight. Grain quality data (% oil, % protein, % starch) was fist collected in 1991 and continues today.

Genetically modified hybrids were first tested in 1998, when 2% of the hybrids entered were Bt European Corn Borer hybrids. In 2004, 38% of the hybrids entered were genetically modified, and included Bt European Corn Borer, Bt Rootworm and Bt/Roundup Ready stacked hybrids.

The data for the past 32 years (1972-2004) has now been summarized and is available online at: Yield, harvest moisture and other characteristics have been summarized by site, with statewide yield averages included as a comparison. Data for herbicide tolerant (i.e. Roundup Ready, Liberty Link) and genetically modified hybrids (i.e. Bt European Corn Borer) that were entered in the test have also been summarized and are included in the document. A white corn test was done in conjunction with the Ohio Corn Performance Test from 1995-2002 and is also available online at:

Contact Allen Geyer (phone: 614-292-1393, email: for additional information.

Requirements for On-Farm Storage of Bulk Fertilizers

Authors: Harold Watters

With higher fertilizer prices, the question of on-farm storage of fertilizer has come up several times this winter. Effective January 2007 any farm using bulk storage for more than 30 days must have secondary containment dikes in place. If you are planning to build or add on to storage now, then you must comply when these new facilities are built.

The Ohio Department of Agriculture has a fairly simple form to request approval for secondary containment plans, this must be done before construction begins and they will inspect the facility after it is built. Information about secondary containment regulations and the form to request installation is available on the ODA website:

Dee Jepsen, in Extension Ag Engineering, has also prepared a FactSheet available through OhioLine with more details.

Those of you interested and living in northwest Ohio can attend a March 3rd meeting from 7 to 9pm in Napoleon. In addition to an Ohio Department of Agriculture representative, a farmer panel will be on hand to talk about their experiences with recently installed secondary containment facilities. Call Dusty Sonnenberg in the Henry County Extension office for more information: 419 592-0806.

Conservation Tillage & Technology Conference February 24 & 25

Authors: Gary Wilson

You can still plan to attend the 16th Annual Conservation Tillage and Technology Conference scheduled February 24 & 25, 2005 at Ohio Northern University in Ada, Ohio.

This year's conference will cover a wide range of topics including soil fertility, planting and seed placement, tillage systems comparisons, soil density, root development, and weed, disease, pest management, and Precision Agriculture Technology. Over 55 sessions will be offered over the two day conference with nearly 65 different speakers including University Specialists, Ag Industry Representatives and producer panels. Featured speakers include Ken Ferrie, Crop Tech, Hayworth , Illinois, Bob Hoeft, Soil Fertility Specialist, University of Illinois, Elwynn Taylor, Agr. Meteorologist, Iowa State University, Mark Hanna, Ext. Ag. Eng.,Iowa State University and Dan Towery, CTIC, Lafayette, IN.

Over 30 credits will be made available for CCA's. Registration which can be taken at the door is $35.00 a day or $50.00 for both days. For a copy of the conference agenda and registration information contact the Hancock County Extension Office at 419-422-3851 or visit the web site at:

Soybean Rust Seminars - March 7, 8, & 9

Authors: Greg LaBarge

Asian Soybean Rust, not if but when will it come. Soybean producers across the United States knew this was the case when experts first began talking about Asian Soybean Rust. Some unfortunate states have already experienced the onset of this disease and others are waiting to see if it will visit their fields.

According to researchers, it is not guaranteed that this disease will hit Ohio but The Ohio Soybean Association (OSA) has developed a series of rust seminars to educate and prepare producers for the upcoming planting season. Dr. Anne Dorrance, The Ohio State University and Dr. XB Yang, Iowa State University, nationally recognized pathology experts will talk about their research experiences and cover fungicides, predictive models and decision making for the 2005 growing season. A spray equipment discussion panel and presentation from industry representatives will also be part of the program.

The seminars will take place on March 7, 8, and 9 from 8:30 a.m. to 1:30 p.m. Admission for OSA members is $20 and for non-members $40. Register for a location nearest you by calling 1-888-SOYOHIO. Registration deadline is Thursday, March 3, 2005. The agenda for these meetings can be found at

Monday, March 7, 2005 – Roberts Convention Center, Wilmington, Ohio
Tuesday, March 8, 2005 – Der Dutchman Restaurant, Plain City, Ohio
Wednesday, March 9, 2005 – Lighthouse Restaurant, Findley, Ohio

Note: This week’s newsletter does not contain a rust information update due to Dr. Anne Dorrance being in Brazil for a closeup look and gathering the latest information on this disease. Her experiences will add to the discussion at the meetings being promoted below. In addition Nancy Taylor, Program Director for the Plant Pest Diagnostic Clinic is also visiting Brazil to see first hand the diagnostic characteristics of soybean rust. Continue watching the AgCrops Team webpage for soybean rust and other crops information:

Archive Issue Contributors: 

State Specialists: Pat Lipps and Dennis Mills (Plant Pathology), Ron Hammond (Entomology), Peter Thomison, Allen Geyer and Rich Minyo (Corn Production) and Robert Mullen (Soil Fertility). Extension Agents and Associates: Gary Wilson (Hancock), Roger Bender (Shelby), Mark Koenig (Sandusky), Dusty Sonnenberg (Henry), Greg LaBarge (Fulton), Bruce Clevenger (Defiance) and Harold Watters (Miami).

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.