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Agronomic Crops Network

Ohio State University Extension


C.O.R.N. Newsletter 2008-33

Dates Covered: 
September 29, 2008 - October 7, 2008
Wesley Haun

Potential for Mold Development in Downed Corn

Authors: Dennis Mills, Pierce Paul

The wind storm from Hurricane Ike that swept across the state during the weekend of September 13-14 caused considerable damage in several corn fields, leaving huge sections of some fields with plants either laying flat on the ground and broken off at various heights along the stalk. Generally, late-planted, greener fields suffered more severe damage than early-planted fields that were drying down at the time of the storm.

As harvest begins, some growers are expressing concerns about the development of Aspergillus and other molds, and the accumulation of toxins such as aflatoxins and vomitoxin in downed corn. Aspergillus and aflatoxins are problems commonly associated with drought-stressed conditions. However, Aspergillus can infect grain and produce aflatoxin under a wide range of conditions: temperature between 54oF and 108oF; kernel moisture between 15-25% and relative humidity above 80%. Downed corn will certainly be exposed to these conditions, especially high moisture if it rains, and since Aspergillus is a soil-borne fungus, infection could easily occur. However, growers should also pay attention to ear rots caused by Fusarium and Diplodia, which could develop if damaged ears come in contact with moist soils. Any condition that increases moisture in the grain, puts maturing grain in contact with the soil, delays maturity, restricts drying, and makes harvest operations difficult could promote mold development and toxin contamination.

Thankfully, since the storm weather conditions have generally been dry, so most of the fields with downed corn and ears in contact with the soil have not been exposed to wet conditions. To minimize potential problems, producers are advised to harvest problem fields as early as possible. A good source for harvesting suggestions may be found at “Information on Harvesting Downed Corn” by Peter Thomison and Randall Reeder in last week's issue of this newsletter. Scout problem fields for discoloration or moldy growth on the ears and have suspect grain samples analyzed for mycotoxins before feeding to livestock.

Time to Give the Sprayer Final Rinsing Before Storage

Authors: Erdal Ozkan

This may be a good time to put your sprayer in a safe place for the winter, unless you intend to spray for winter annual weeds after grain harvest. The most important thing is to clean it thoroughly before storage.

Many pesticides cause rapid corrosion of metal parts in the spraying system. Pesticides should be washed from the whole system immediately after use. Cleaning a sprayer thoroughly not only increases its life, but also reduces the chance of cross contamination of chemicals and prevents crop injury.

The cleaning solution used depends on the pesticide used. Always check the pesticide label for specific cleaning instructions. A solution containing 2 pounds of detergent for each 30 to 40 gallons of water is sufficient for removing most pesticides. First, flush sprayer with clean water. Then add the cleaning solution to the tank. Agitate thoroughly and allow the water-detergent solution to circulate through the system for several minutes. Remove nozzles and flush the system twice with clean water. Clean nozzle tips and screens in a strong detergent solution or kerosene, using a soft brush such as an old toothbrush.

Some pesticide combinations (especially if oil is used) may produce a putty-type paste (buttering out) in the tank. Flushing out the residuals of such chemicals after each load may prevent an accumulation. If water alone does not dissolve and remove the buildup, prepare a mixture of water and solvent such as kerosene, diesel fuel, or comparable light oil (1 gallon solvent for 25 gallons of water). Allow paste to dissolve, then agitate, and flush. Next, flush with detergent and clean water as explained in the previous paragraph.

After rinsing the equipment with an oil-based solvent or a water-detergent solution then rinse with one of the following in 25 gallons of water: 1 quart of household ammonia, or 1 cup of trisodium phosphate (TSP). Circulate this solution and let a small amount flow through the nozzles. Keep the remainder of the solution in the system approximately 6 hours (or overnight), and then pump it out through the nozzles. Finally, remove the nozzles, strainers, and flush the system twice with clean water.

Cleaning the outside of the sprayer components deserves equal attention. Remove compacted deposits with a bristle brush. Then flush the exterior parts of the equipment with water. A high pressure washer can be used.

When cleaning a sprayer, select an area where it will not contaminate water supplies, streams, crops, or other plants, and where puddles will not be accessible to children, pets, livestock, or wildlife. Preferably, the area should have a wash rack or cement apron with a well-designed sump to catch contaminated wash water and pesticides. Spray the rinse water and the cleaning solution on the same field where the pesticide was applied in a manner consistent with the intended use of the chemical. Avoid discharging the whole cleaning solution in a small area.

The quickest, easiest way to rinse a tank and spraying equipment and dispose of the waste safely is to carry a 25 to 50 gallon drum of fresh water with the spraying equipment. When spraying is finished, flush the system in the field. A concrete pad with a rinsate collection pit can be used to wash the interior and exterior of the sprayer without creating potential contamination of soil, ground water, and surface water. Most importantly, the concrete rinse pad also helps contain pesticides that are spilled on the sprayer or to the ground during loading or mixing.

New Wheat Bulletin

Authors: Dennis Mills, Pierce Paul

“Improving Wheat Profits in Ohio” is a new Bulletin for Ohio wheat growers. Wheat is very important to Ohio’s farm economy. It is the most widely grown food crop in the state but low prices, production problems, poor weather and disease outbreaks often reduce production on some farms. This new publication provides up-to-date information on planting, fertility, critical growth stages identification, disease thresholds and fungicides, weed control and herbicides, and insecticides prepared by state specialists in each of these major wheat production areas. It also features a listing of small grain producers in Ohio. Bulletin 938 can be obtained from The Ohio State Extension eStore or from your local county Extension office.

Weather Report

Authors: Jim Noel

After a warm and mainly dry week last week, this week will be sharply cooler. A cold front will bring some rain Monday night to Ohio with the greatest potential in western Ohio which could exceed 0.50 inch. Most areas in the east will see less than 0.25 inch of rain. Remainder of the week will be cool with some sporadic light rainfall providing approximately 0.1 – 0.2 inch, mainly in the north.

The month of October appears to be near normal temperatures and below normal rainfall. However, keep in mind this is one of the driest months of the year from a climate perspective so even normal rainfall would be only a few inches.

Archive Issue Contributors: 

State Specialists: Ann Dorrance, Pierce Paul, and Dennis Mills (Plant Pathology), Ron Hammond (Entomology), James Noel (NOAA/NWS/OHRFC). Extension Agents and Associates: Roger Bender (Shelby), Harold Watters(Champaign), Mike Gastier (Huron), Les Ober (Geauga), Wesley Haun (Logan), Steve Foster (Darke), Todd Mangen (Mercer), Gary Wilson (Hancock), Glen Arnold (Putnam), Greg LaBarge (Fulton), Bruce Clevenger (Defiance), Steve Bartels (Butler), Jonah Johnson (Clark), Tim Fine (Miami), Ed Lentz (Seneca), and Steve Prochaska (Crawford).

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.