CORN
Crop Observation and Recommendation Network

September 16 - September 22, 2002
C.O.R.N. 2002-31

In This Issue:

A) Get Ready To Plant Wheat
B) Grain Moisture In Corn May Be Lower Than You Think
C) Corn Yields In 2002 - "Slim Pickin's" Likely In Many Corn Fields
D) Rye Production In Ohio
E) Free Nitrate Testing Of Corn Stalks And Silage
F) Visit The Extension Crops Team At Farm Science Review
G) Precision Agriculture Featured At Farm Science Review

A) Get Ready to Plant Wheat - Pat Lipps CORN Questions

Recent rains in some parts of Ohio have relieved grower concerns for planting wheat into dry soils. However, most areas of the state are very dry and considerable rainfall is needed to bring the soils back to near normal moisture levels. Regardless of the moisture present in soils, Ohio wheat producers should plant wheat on or soon after the Hessian Fly Safe Date. In fact the best yields are nearly always obtained by planting within the first 10 days of the Hessian Fly Safe Date. History has told us that under adverse moisture conditions wheat seed will remain in soil until adequate moisture is available for germination. To help insure high germination rates all wheat seed should be treated with a seed treatment fungicide to protect against seed and soil-borne fungi. Fusarium is usually the most important pathogen causing damage to young seedlings in dry soil. Treating seed with seed treatment products that contain Thiram or thiabendazole (TBZ) will give extra protection against Fusarium (See more on seed treatment products for wheat at http://www.oardc.ohio-state.edu/ohiofieldcropdisease/wheat/wheatseedtreatments.htm).

Hessian fly occurs throughout Ohio and survives in wheat stubble on volunteer wheat and grasses during the summer. Wheat producers can avoid damaging infestations by planting wheat after the designated Hessian Fly Safe Date for their county. Additionally, delayed planting until after this date will help reduce several important wheat diseases like barley yellow dwarf. Wheat planting should begin in the most northern counties of Ohio on September 22. Hessian fly safe dates are progressively later for counties farther south and range from September 22 to Oct 5 (See actual Hessian Fly Safe Date for your county at http://ohioline.osu.edu/iwy/flydates.html).

Regardless of soil moisture, plant wheat 1 to 1.5 inches deep using 1.2 to 1.6 million seed per acre. This seeding rate provides about 17 to 23 seed per foot of row in 7.5 inch row spacing. Do not plant wheat too shallow because the seedlings will be vulnerable to dying at the soil surface this fall and frost heaving later this winter and spring. Additionally, apply 20 to 30 lb of nitrogen at planting to enhance fall growth and overall vigor of the crop. Research in Ohio has shown the advantages of applying some nitrogen in the fall to increased yield potential of the crop.

Please remember, as Dr. Jim Beuerlein, outlined in the C.O.R.N. article last week (CORN 2002-30, Sept. 9-15, 2002; available at http://corn.osu.edu/archive/2002/sep/02-30.html), excessively high rates of nitrogen and very high seeding rates (greater than 30 seed per foot of row) are of no advantage in Ohio and only lead to less profitability. Yields of 85 to 100 bu/A are attainable by most wheat producers most years with adequate and timely management. Please take time to review standard management practices by obtaining a copy of 'Improving Wheat Yields in Ohio' from your county OSU Extension office or view it on the web at http://ohioline.osu.edu/iwy/index.html

B) Grain Moisture in Corn May be Lower Than You Think - Peter Thomison CORN Questions

Despite the relatively late planting season we experienced this year, high temperatures, drought conditions, premature plant death, etc., are contributing to rapid grain drying in many corn fields. The ideal kernel moisture level to harvest corn at for dry grain storage is considered 25%. The yield potential of corn fields in localized areas could drop considerably if harvesting is delayed much beyond maturity because of poor stalk quality. This year's drought plus limited root development due to early season weather conditions could predispose crops to stalk quality problems.

The loss of one "normal" sized ear per 100 feet of row translates into a loss of more than one bushel/acre. In fact, an average harvest loss of 2 kernels per square foot is about 1 bu/acre! According to an OSU ag engineering study, most harvest losses occur at the gathering unit with 80% of the machine loss caused by corn never getting into the combine.

Corn will normally dry approximately 3/4 to 1% per day during favorable drying weather (sunny and breezy) during the early warmer part of the harvest season from mid-September through late September (probably a week to 10 days earlier, respectively, for southern and northern Ohio). By early to mid-October, drydown rates will usually drop to 1/2 to 3/4% per day. By late October to early November, field drydown rates will usually drop to 1/4 to 1/2% per day and by mid November, probably 0 to 1/4% per day. By late November, drying rates will be negligible.

Estimating drydown rates can also be considered in terms of Growing Degree Days (GDDs). It takes about 30 GDDs to lower grain moisture each point from 30% down to 25%. Drying from 25 to 20 percent requires about 45 GDDs per point of moisture. In September we generally average 10 to 15 GDDs per day. In October (as things cool down) the rate drops to 5 to 10 GDDs per day. However, note that the above estimates are based on generalizations, and it is likely that some hybrids vary considerably from this pattern of drydown.

We conducted evaluations of corn drydown at the OSU-OARDC Western Branch Research Farm, near S. Charleston, OH in 1991 and 1992. In 1991, under warm, dry fall conditions, grain moisture loss per day ranged from 0.76 to 0.92%. Whereas under cool, wet fall conditions in 1992, grain moisture loss per day ranged from 0.32 to 0.35%. Grain moisture losses based on GDD ranged from 24 to 29 GDD/percent moisture (i.e., a loss of one percentage point of grain moisture per 24 to 29 GDD) in 1991, whereas moisture loss ranged from 20 to 22 GDD in 1992. The number of GDDs required to reduce grain moisture was lower in 1992 than 1991.

C) Corn Yields in 2002 - "Slim Pickin's" Likely in Many Corn Fields - Peter Thomison CORN Questions

This summer's high temperatures and lack of rainfall have cut yields dramatically in many Ohio corn fields. Table 1 compares average grain yields for past drought years with average yields for the preceding five years. This year's drought has been likened to the droughts of 1983 and 1988 in which yields were reduced by 26% when compared with the average yield of the previous five years. Average yields for 2002 are projected at 110 Bu/A according to the Sept. 12 USDA estimate (which would represent about a 20% decrease in yield compared with the previous five years, i.e. 1997-2001), but it's likely to drop further. In past years with similar weather conditions, yield estimates generally have been revised downward until January of the following year.

Source: National Agricultural Statistics Service http://usda.mannlib.cornell.edu/reports/nassr/field/pcp-bb/2002/crop0902.pdf

D) Rye Production in Ohio - Steve Prochaska CORN Questions

Rye has been used by Ohio farmers as both a cover crop to prevent soil erosion and as a forage for beef and dairy cattle. A potential new use is the production of rye straw for horse bedding. Rye has not been extensively used as a feed grain due to its low yield potential.

Rye is very winter hardy, drought tolerant, and will grow late into the fall. The larger forage type ryes have the ability to create considerable plant biomass by the middle of May in most years. Because rye silage is made in May in northern Ohio, corn or soybeans can be planted after rye with good results. However, it should be noted that rye is very attractive to slugs and armyworms, and as such subsequent crops will need to be monitored closely.

Rye cultural practices are similar to wheat with the exception of nitrogen rate, which should be 20-30 lbs/acre less due to lower grain yield potential. Rye can be planted before the fly-free date to the end of October with satisfactory results. Seeding rates of 90-120 lbs/acre will be adequate. Sow seed 1 to 1.5 inches deep using no-tillage or conventional tillage techniques. Apply a small amount of nitrogen in the fall to stimulate growth (10-25 lbs/acre). Phosphorus (P) and potassium (K) can be applied at similar rates as used for wheat. The critical wheat/rye soil test levels for P and K are 50 lbs/acre P and 250 lbs/acre K at CEC of 15. Rye forage will remove about 0.7 lbs P2O5 and 1.3 lbs K2O per ton.

In regard to rye varieties, most rye planted in northern Ohio is common rye, but there are rye varieties adapted to forage production that have been tested for grazing in southern Ohio. Contact David Samples, Jackson County Extension Agent (samples.1@osu.edu), for details. Among these varieties are Aroostook, Winter King, Elbon, and Pastor. Other varieties that may be available include Hancock and Rymin.

E) Free Nitrate Testing of Corn Stalks and Silage - Ohio Department of Agriculture CORN Questions

Ohio farmers concerned about elevated levels of nitrate content in drought-stressed corn stalks to be chopped for forage or silage for livestock may send samples to the Ohio Department of Agriculture (ODA) in Reynoldsburg to be tested free of charge. Testing will also be performed on fermented silage samples.

Although the severity of the drought varies across different regions of Ohio, farmers in most areas have faced adversely dry weather conditions this growing season. Because of this, corn stalks should be tested for nitrate content before being fed to livestock.

During drought, inefficient uptake of fertilizer by corn causes nitrate to accumulate in the lower portion of the plants, and nitrate concentrations above 1,000 parts per million (ppm) in forage can pose health risks to livestock. Acute nitrate poisoning in livestock may result in difficulty breathing, blue mucous membranes, a rapid weak pulse, dark brown blood, weakness, or muscle tremors. Longer exposures may result in abortions, retarded growth, and sudden death.

Meaningful results depend on a good representative sample. Due to varying moisture levels in fields, the nitrate concentration in a corn stalk may vary by field location. Representative samples should be collected from six different areas in the field. Start three inches above the ground, and take 18 inches of the stalk. Coarsely chop up the stalks, mix them together, and send approximately one gallon of the material to the Ohio Department of Agriculture, Consumer Analytical Laboratory, 8995 E. Main St., Reynoldsburg, OH 43068. Farmers should include their name, complete address, and phone number with area code.

Sample results can be expected in three to five business days after receipt of the product. Lab results cannot be released over the phone, so for a quicker response than mail, include a fax number where results can be sent.

For additional information about the testing program, Ohio farmers can
also call the department's Consumer Analytical Laboratory at 614-728-6230.

F) Visit the Extension Crops Team at Farm Science Review - Ray Wells CORN Questions

The OSU Extension Agronomic Crops Team and the Precision Agriculture Team encourage everyone to stop by and visit our display area at this year's Farm Science Review, September 17-19, at the Molly Caren Agricultural Center near London. The first 35 visitors each day to this display who complete a short survey will receive a free gift. That gift is a copy of the new version of the Corn, Soybean, Wheat, and Alfalfa Field Guide, OSU Extension Bulletin 827, which is a $4.50 value. These team displays will be located in the Alumni Park on Friday Ave., across from the Utzinger Garden and the Bailey and Firebaugh Buildings, near the center of the main exhibit area.

G) Precision Agriculture Featured at Farm Science Review - Matt Sullivan CORN Questions

The Precision Agriculture Team within OSU Extension is sponsoring a precision agriculture field demonstration in the afternoon during each day of Farm Science Review, September 17-19. The field demonstration will run from 1:00 to 4:00 Tuesday (Sept. 17) & Wednesday (Sept. 18), and 1:00 to 3:30 on Thursday (Sept. 19). We will have one of the largest demonstrations and displays of GPS-based vehicle guidance systems in the country. There will be nine different driving aids (lightbar guidance systems) and four auto-steering tractors.

Farm Science Review visitors will be able to drive the utility vehicles with the lightbar guidance systems and see the auto-steering systems up close. The first GPS-based auto-steering combine ever to be released for commercial operation in the United States will be shown in the soybean harvest demonstration. The application of hand-held computers and GPS receivers will be demonstrated for use in agriculture. Along with the field demonstrations, there will be a tent in Alumni Park (Friday Ave.) featuring other precision agriculture activities at OSU such as new sensor technologies, remote sensing and a yield monitor simulator. We invite you to see our precision agriculture activities during Farm Science Review. Come see the future of agriculture!

Readers can subscribe electronically to this newsletter by sending an e-mail message to: corn-out-on@postoffice.ag.ohio-state.edu. A successful subscription message will receive by an automatic reply from the listserv. Contact your local Ohio State University Extension Office or e-mail labarge.1@osu.edu if you have problems subscribing.

Past versions of C.O.R.N. can be found on the World Wide Web at: http:/www.ag.ohio-state.edu/~corn/archive/

C.O.R.N. is a summary of crop observations, related information, and appropriate recommendations for Ohio Crop Producers and Industry. C.O.R.N. is produced by the Ohio State University Extension Agronomy Team, State Specialists at The Ohio State University and Ohio Agricultural Research and Development Center. C.O.R.N. Questions are directed to State Specialists, Extension Associates, and Agents associated with Ohio State University Extension and the Ohio Agricultural Research and Development Center at The Ohio State University.

Editor: Andy Kleinschmidt        Web Editor: Tom Rosati

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