CFAES Give Today
Agronomic Crops Network

Ohio State University Extension


C.O.R.N. Newsletter 2009-24

Dates Covered: 
July 28, 2009 - August 4, 2009
Howard J. Siegrist

Will Cooler than Normal Temperatures Adversely Affect Corn Yields?

Authors: Peter Thomison

Some Ohio growers are concerned that the lower than normal temperatures we experienced in July will negatively impact corn growth and grain yields. Jim Noel noted in his “Weather Update”, that this summer is far cooler than 2004, 2000, 1996 or 1992, and that this month will go down as the coolest or near coolest July in anywhere from 25 to over 100 years - depending on where you are in the state and how the month ends. So, should these “cool” temperatures concern us? Probably not…it’s important to remember that corn actually yields best with moderate temperatures (and adequate soil moisture). Temperatures that occur in Ohio in July (especially at night) are often warmer than optimum for corn. The ideal daytime temperatures for corn are about 80 to 86 degrees F (and higher if moisture is plentiful at all times). Although some believe that corn grows best when nights are hot, past research shows that warm temperatures adversely affect yield potential. While temperatures in the 40’s may impair photosynthesis, high night temperatures (in the 70’s or 80’s) result in wasteful respiration and a lower amount of dry matter accumulation in plants. With high night temperatures, more of the sugars produced by photosynthesis during the day are lost; less is available to fill developing kernels, thereby lowering potential grain yield. Research conducted at the University of the Illinois indicated that corn grown at night temperatures in the mid-60’s out-yielded corn grown at temperatures in the mid-80’s. High night time temperatures result in faster heat unit (GDD) accumulation that can lead to earlier corn maturation, whereas cool night temperatures result in slower GDD accumulation that can lengthen grain filling and promote greater dry matter accumulation and grain yields.

Corn yields are often higher with irrigation in western states, which have low humidity and limited rainfall. While these areas are characterized by hot sunny days, night temperatures are often cooler than in the Eastern Corn Belt. Low night temperatures account in part for some of our highest corn yields in Ohio - 143 and 158 bu/A in 1992 and 2004, respectively (the highest yields recorded to date at that time). During most of the 2004 growing season, temperatures were below normal. From late June through most of August, a period of time that included most of the grain fill period, weekly temperatures were cooler than normal - as much as 4 to 7 degrees below normal in August. Cool night temperatures in 2004 may have reduced respiration losses during grain fill.

In parts of the Ohio this year where rainfall has been below average since mid June, the cooler than average temperatures were critical in minimizing what could have been severe drought stress if we’d had normal or higher temperatures. The cool temperatures may have also slowed the development of foliar diseases and insect problems.

So what’s the “downside” to these lower than average temperatures? Cooler temperatures (if they continue) could delay grain harvest and result in higher grain moisture. Growers may want to consider this possibility when they estimate fuel costs for drying grain. Cool temperatures have also been associated with certain ear disorders and reduced kernel set (“scrambled silks” or “silk balling” and “blunt ear syndrome”). However, these problems are usually uncommon and limited to certain hybrid genetic backgrounds.

This article contains information I’ve adapted and cited from the “Climate and Corn” section in Modern Corn and Soybean Production by R.G. Hoeft, E. D. Nafziger, R.R. Johnson, and S.R. Aldrich. (Published 2000. MCSP Publications, Champaign, IL).

Soybean Aphid Update

Authors: Bruce Eisley, Andy Michel, Ron Hammond

As we approach the end of July, we still are not aware of any soybean aphid problems in Ohio; thus, there should be no reason for wide spread spraying for aphid control. However, this week was approximately the time in 2007 that we began finding heavy populations in northeast Ohio after winged aphids had migrated into the state, most likely from Quebec. Thus, we still need to keep vigilant and not be caught off-guard in case soybean aphids are blown into Ohio from the north. And at this time, aphid populations are again heavy in Quebec, and starting to build in Ontario. We continue to urge growers to scout their fields, not only to become aware of possible economic populations, but also to reassure themselves that soybean aphids might not be a concern in their fields. Remember, there is no reason to treat fields that are below the economic threshold of 250 aphids per plant!

Planning for the 2010 Wheat Crop

Authors: Rich Minyo, Pierce Paul, Jim Beuerlein

The outstanding 2009 wheat crop has everyone asking if we can duplicate it in 2010. The simple bottom line answer is, YES, if we have the same good growing season we had in 2009 including the low level of disease. Most producers do their best to grow a good crop by adopting the following cultural practices:

•Plant after the Hessian fly-safe date to reduce risks from Hessian fly and barley yellow dwarf disease. For the most northern counties, the Hessian fly-safe date is Sept. 22, and for most southern counties the date is around Oct. 4.
•Apply 20-30 pounds of Nitrogen per acre before planting, and be sure the soil Phosphorous level is above 25 ppm and the soil pH above 6.5. Check the Agronomy Guide for fertilization recommendations.
•Plant at the right seeding rate - 18 to 25 seeds per foot of row for both a 7.5 and 15 inch row spacing.
•Plant at the right seeding depth - 1.0 to 1.5 inches deep.
•Select a variety that will perform well in the environment and cultural practices that prevail. For example, if Powdery mildew is always a problem, then select a variety with resistance to that disease.

The excellent quality of the 2009 crop has producers asking about using their harvested grain as seed for the 2010 crop or if they should buy new seed. Currently, most varieties developed by private companies are protected and may not be saved and used for seed. There are a few publically developed varieties of wheat that may be saved and used for seed. Those varieties include: Benton, Branson, Bravo, Cooper, GR962, Hopewell, Malabar, Roane, Shirley, Sunburst, Truman, and W1377. If in doubt about the protection status of a variety, be sure to check with the owner about the legality of using your grain of that variety for seed.

If it is legal to use some of your harvested grain for seed, here are some things to consider to be sure it is of adequate quality to be used for seed: 1) Get a germination test and a stress test performed to determine if the grain will germinate under stress conditions. 2) Get the grain cleaned to remove weed seed, poorly developed or diseased seed, and foreign matter. 3) Get the grained treated with the appropriate fungicides for protection against seed- and soil-borne diseases. These are some of the same activities all seed producers must perform to provide quality seed. Additionally, they take extra steps in harvesting and handling of harvested seed to reduce seed damage and maintain high seed quality.

Some producers are interested in growing wheat in rows spaced 15 inches apart while other producers use wide row wheat for relay-intercropping with soybeans. Variety selection is critical for the success of both production systems, and we have identified varieties that are suitable for each of those production systems in the 2009 Ohio Wheat Performance Test bulletin which will be published in the Ohio Country Journal in Mid- August and will also be available at County Extension offices sometime in early August.

Protect your Wheat Seed While Waiting for Planting Season

Authors: Curtis Young

Storage of wheat seed in gravity grain wagons is a common practice in Ohio. However, this practice can have some negative consequences such as insect infestation. While the wheat seed lays in the grain wagon for several months during the summer it is usually open to insect infestation, especially by Indianmeal moth and granary weevil.

Start with a clean insect-free grain wagon. The grain wagon should have been thoroughly cleaned before the wheat seed was placed into it for short-term storage.

If one does not want to use any kind of an insecticide treatment on the wheat seed, then one could attempt to construct a physical barrier to try to prevent insect access to the stored wheat seed. This would require building a frame to tightly fit over the top of the grain wagon covered with a fine mesh screen that would prevent flying insects’ access to the top of the grain. This would not be 100% full proof since there would most likely be numerous other avenues for insects to gain access to the grain.

The next course of action would be to use one of a couple of insecticide treatments available for treating stored grain/seed. These included an organic, a biological and standard insecticides.

The organic compound is Diatomaceous Earth (silicon dioxide) (e.g. Insecto (Natural Insecto Products, Inc.)) which is an abrasive powder that cause holes to develop in insect cuticles resulting in desiccation and death of insects that come into contact with the product.

The biological pesticide is the Bt products (e.g. DiPel DF (Valent BioSciences Corporation)). The one draw back to this material is that it is only effective against moths and in Ohio that would be the Indianmeal moth. However, this is probably the most common infester of stored wheat seed in gravity wagons.

The standard insecticides that carry labels for treatment of wheat seed are Storcide II and Suspend SC.

Storcide II (3.7% deltamethrin and 21.6% chlorpyriphos-methyl) (Bayer CropScience) is the replacement product for Reldan (chlorpyriphos-methyl alone).

Suspend SC (4.75% deltamethrin) (Bayer Environmental Science) has recently amended its label to include store grain and seed. However it may not be available to private applicator. The label specifically states for sale to, use and storage by pest control operators and/or Commercial Applicators. Check with your local chemical dealer to see which of these products would be available to you for purchase and use.

To use Storcide II, the grain would most likely need to be moved from one grain wagon to another and while it is being moved, it could be treated with the product according to the label.

Treatment of the wagon wheels and frame with an approved insecticide could prevent crawling insects from gaining access to the wheat seed from the ground.

Remember to read and follow all insecticide labels and pay strict attention to safety precautions.

SmartStax Corn Gets Approval

Authors: Bruce Eisley, Andy Michel, Mark Loux, Peter Thomison, Ron Hammond

Monsanto and Dow AgroSciences announced on July 20 that they have received registration approval from the U.S. Environmental Protection Agency (EPA) and are on track to commercialize SmartStax corn hybrids in 2010. This approval, or authorization, was also received in Canada. SmartStax hybrids contain eight transgenic traits - three for below ground insect control; three for above ground insect control, and two providing different types of herbicide resistance. The hybrids will express the following insecticidal proteins: Cry1F and Cry1A.105+Cry2Ab2 for European corn borer, black cutworm, fall armyworm, and western bean cutworm control, and Cry3Bb1 and Cry34/35Ab1 for corn rootworm control. SmartStax hybrids will also provide herbicide tolerance to glyphosate and glufosinate with the addition of the Roundup Ready 2 and Liberty Link genes. The approval will allow growers in the US Corn Belt who use the hybrids to reduce refuge size from 20% to 5%. The companies indicated they intend to introduce SmartStax hybrids across 3 to 4 million acres in 2010. Whether any will be available in Ohio is unknown at this time.

ACRE or DCP: Which One to Choose?

Authors: Chris Bruynis

Farmers needing to decide between the 2008 Farm Bill’s average crop revenue election (ACRE) and the traditional direct and counter cyclical program (DCP) have until August 14, 2009 to make up their mind. In order to make the election, farmers need to understand the strengths and weaknesses of both programs. Traditional DCP has direct payment, marketing loan, and price counter-cyclical components while ACRE has a reduced direct payment and marketing loan component plus the average crop revenue election component. DCP and ACRE programs are summarized in Table 1.

Option 1 Option 2
Direct and Counter Cyclical Program Average Crop Revenue Election Program
Direct Payment - $18.55/acre (83.3*payment rate*direct yield*base acres) Direct Payment – $14.84/acre 80% of direct payment from Option 1
Payment rates for 2009 Average payment reduction is $3.71 per acre in Ohio
$0.28/bu Corn
$0.44/bu Soybeans
$0.52/bu Wheat
Market Loans/LDPs Market Loans/LDPs
Market loan rates for 2009 in Wyandot County (rates vary by county) 70% of market loan rate from Option 1
$1.94/bu Corn $1.36 Corn
$5.12/bu Soybeans $3.58 Soybeans
$1.96/bu Wheat (SRW) $1.37 Wheat (SRW)
Counter Cyclical Payment Average Crop Revenue Elections
Payment received when the average U.S. cash price for the marketing year falls below the following prices (target price minus the direct payment rate) Payment received when the 2009 average Ohio crop yield times the average U.S. cash price falls below the State ACRE Revenue Guarantee1
$2.35/bu Corn $558/acre Corn2
$5.36/bu Soybeans $416/acre Soybeans
$3.40/bu Wheat (all wheat) $393/acre Wheat (all wheat)

1The 2009 revenue must also be below the farm revenue guarantee.
2This number represents the preliminary state revenue guarantee as of July 10, 2009. Revenue guarantees will become final for the 2008 corn and soybean crop on September 30, 2009. The wheat revenue guarantee for the 2008 crop was finalized June 30, 2009.

Direct payments are calculated on base acres and historic yields of crops. This payment is not triggered by price or yield conditions. In Ohio the average payment is $18.55 per acre. If a farmer elects DCP he would receive the entire amount but if he elects ACRE the amount would be reduced by 20% and would, on the average, equal $14.84.

Market loans rates vary slightly for each county in Ohio. If a farmer wanted to store grain in bins on the farm and borrow against the grain, more bushels would need to be leveraged as collateral to borrow the same amount of money if ACRE is elected over DCP. Unlike past years where farmers could select the day to determine LDP’s, a 30 day average price will now be used for both DCP and ACRE to determine LDP payments. Under ACRE the price would need to be 30% lower before LDP’s would be paid compared to DCP levels.
Counter-cyclical payments would be made if the average U.S. cash price for the 2009 marketing year falls below the listed price per bushel for each commodity. Payments would be calculated on base acres multiplied times counter-cyclical yields for each farm. ACRE payments would be made if the 2009 Ohio average yield multiplied times the 2009 average U.S. cash price is lower than the State ACRE Revenue Guarantee for each crop respectively. If this occurs, then each farm enrolled in ACRE would also need to have their 2009 revenue below the farm’s revenue guarantee.

Even though ACRE is a revenue guarantee program, most farmers understand price better. Assuming an average yield for the 2009 Ohio crop, the 2009 average U.S. cash price would need to be below the prices listed in the following table in order for ACRE to make a payment. For example, if the Ohio corn crop averaged 150 bushel per acre and the average price of corn between October 1, 2009 and September 30, 2010 was $3.50, farms enrolled in ACRE would receive an ACRE payment providing their revenue was also below the predetermine farm revenue guarantee. Conversely, if the average price of corn for the same period was $4.00, no payment would be made. If the average Ohio corn yield was 157.5 bushels per acre in 2009, the price would need to be below $3.53 before ACRE payments were triggered at the state level. Likewise, an average corn yield of 142.5 would need corn below $3.90 to trigger ACRE payments.

  Ohio Olympic Average Yield U.S. average cash price to equal revenue guarantee; 5% reduced yields U.S. average cash price to equal revenue guarantee; average yields U.S. average cash price to equal revenue guarantee; 5% increased yields
Corn 150.0 bu $3.90 $3.72 $3.53
Soybeans 46.0 bu $9.50 $9.05 $8.59
Wheat2 65.8 bu $6.27 $5.97 $5.67

2The price for wheat reflects a blended wheat price to include all wheat varieties not just soft red winter wheat.

To illustrate the differences in farm program payments an example 100 acre farm with three scenarios consisting of 100 acres of corn, 100 acres of beans and 100 acres of wheat was used. This farm has 42 acres of corn base, 47 acres of soybean base and 11 acres of wheat base. The following table illustrates the expected farm program payments for DCP and ACRE under different price scenarios holding the 2009 yields constant at the state Olympic average. This example is also using the preliminary State ACRE Revenue Guarantee for corn and soybeans which could change through September 30, 2009.

U.S. Average Cash Price $4.00 $3.50 $3.00 $2.50 $2.00 $1.50
Farm Program Payments:
DCP $19 $19 $19 $19 $35 $105
ACRE $15 $50 $112 $132 $132 $132
U.S. Average Cash Price $9.00 $8.00 $7.00 $6.00 $5.00 $4.00
Farm Program Payments:
DCP $19 $19 $19 $19 $24 $70
ACRE $17 $54 $92 $100 $100 $100
All Wheat  
U.S. Average Cash Price $6.25 $5.50 $4.75 $4.00 $3.25 $2.50
Farm Program Payments:
DCP $19 $19 $19 $19 $21 $50
ACRE $15 $40 $79 $92 $92 $92

What if the farmer had planted 45 acre of corn, 45 acres of beans and 10 acres of wheat under the same price scenarios? Assuming crop prices track up and down together as illustrated, the following table shows the anticipated payments for the example farm.

U.S. Average Cash Price
Corn $4.00 $3.50 $3.00 $2.50 $2.00 $1.50
Soybeans $9.00 $8.00 $7.00 $6.00 $5.00 $4.00
Wheat $6.25 $5.50 $4.75 $4.00 $3.25 $2.50
Farm Program Payments
DCP $19 $19 $19 $19 $42 $99
ACRE $15 $51 $100 $115 $115 $115

Simplifying DCP and ACRE to make them easily understood is difficult. These prices and payment levels, even though they are accurate under the assumptions, are for illustrative purposes only. Farmers should take time to complete spreadsheet programs to calculate their anticipated benefit from the DCP and ACRE programs to determine which option is the best for them.


Weather Update

Authors: Jim Noel

It should be noted that this cool summer is far cooler than 2004, 2000, 1996 or 1992. Don't you like the every 4 years thing? However, you can't keep that streak up as 1988 was hot. This will go down as the coolest or near coolest July in anywhere from 25 to over 100 years depending on where you are in the state and how the month ends.

The other thing is we called for a cool summer with big heat back in early spring so that was a very good forecast.

The outlook for the next two weeks calls for normal temperatures and near or slightly below normal rainfall, though most places will get some more rain. The next chances for rain will be for the second half of this week. We do expect the switch to a warmer and drier pattern this fall.

Here are the July stats. (The last time July was cool overall would be 2004, then 2000 then 1996 then 1992).

Here are the top coolest July's and where we fall this year overall: Columbus: 70.0 – 1891; 70.5 – 1971; 70.6 – 2009; Dayton: 69.0 – 2009; 69.9 – 1984; 71.1 – 1947; Cincinnati: 69.8 – 2009; 70.7 – 1947; 71.4 – 1891; 72.1 – 1996.

The highest maximum temperature so far this month: Dayton - 86; Cincinnati - 85; Columbus - 88

Total number of 90 degree days this year: Dayton – 3; Cincinnati – 3; Columbus - 2

This cool year is more a function of the weather pattern combined with such features as coming out of a La Nina, decent soil moisture, longest sunspot minimum in nearly a century per NASA, and a persistant low just north of the Great Lakes in the upper atmosphere.

Cover Crop Twilight Field Day

Authors: Roger Bender

Plan to attend the Cover Crop Twilight Field Day scheduled for Monday, August 3rd in Shelby County. The 6:30-8:30 PM program will be conducted near Anna, Ohio, exit 99 on Interstate 75. Travel east three miles on St. Rt. 119, then south one mile on Pasco-Montra Road to Meranda Road. Follow the signs.

15 X 50 ft. demonstration plots will be in a wheat stubble field, some of which will be fertilized with liquid beef manure. Species to be utilized include oilseed radish, oats, cereal rye, Sudan grass, Austrian winter pea, cow pea and buckwheat. In a soybean field directly south across Meranda Road, Austrian winter pea, cereal rye, oats and wheat will all be broadcast before leaf drop, and also drilled after soybean harvest.

Alan Sundermeier, co-coordinator of Ohio State University Extension's Sustainable Agriculture Team, will review recommended seed rates, depths and dates and weed control recommendations.

The Miami Conservancy District is initiating a major incentive program this year for cover crops worth up to $50 per acre. This will be available for all cropland draining into the Great Miami River. Jason Bruns from the Loramie Valley Alliance and the local SWCD will review details necessary for farmers to qualify.

All of the plots will be left untouched until spring planting. Demonstrated seedings into the wheat stubble will be identified by signs throughout the corn growing season, enabling farmers to visually compare the impact of cover crops on growing corn.

For more information, please contact Roger Bender at 937.498.7239 or


Archive Issue Contributors: 

State Specialists: Pierce Paul, Dennis Mills (Plant Pathology), Ron Hammond, Andy Michel, Bruce Eisley (Entomology), Peter Thomison, Rich Minyo (Horticulture and Crop Sciences), Mark Loux (Crop Sciences) and Jim Noel (NOAA). Extension Educators and Associates: Glen Arnold (Putnam) Roger Bender (Shelby), Chris Bruynis (Wyandot), Bruce Clevenger (Defiance), Tim Fine (Miami), Mike Gastier (Huron), Wes Haun (Logan), Jonah Johnson (Clark), Ed Lentz (Seneca), Les Ober (Geauga), Howard Siegrist (Licking), Alan Sundermeier (Wood), Harold Watters (Champaign) and Curtis Young (Hancock).

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.