Farmers, get that corn out of the fields

COLUMBUS, Ohio – Low grain prices, unfavorable weather and hurricane-related transportation issues have some Ohio growers dragging their feet with corn harvest. But, any further delay could cause severe stalk lodging and subsequent yield losses.
Farmers should harvest corn as soon as field conditions are suitable for equipment entry, and they should first target fields at greatest risk of stalk lodging, said Peter Thomison, an Ohio State University Extension agronomist with the Department of Horticulture and Crop Science.
Stalk lodging. Stalk lodging is stalk breakage below the ear, which is caused by severe late-season weather, European corn borer infestations, stalk rot, or a combination of these. The condition can slow harvest and cause significant yield losses.
Early season weather – a wet, cool spring, followed by a hot, dry summer – has contributed to some of the worst stalk quality problems in several years, Thomison said.
Late harvesting. According to the Ohio Agricultural Statistics Service, about 42 percent of the state’s corn has been harvested. The longer growers wait to harvest, the more severe the problem will become.
Recent Ohio State University Extension research on delayed harvesting has shown that the majority of stalk lodging occurs between early to mid November and early to mid December.
In the early stages of harvest delay, Thomison said stalk rotting occurs and is followed by stalk lodging.
He said as much as 20 to 30 percent of hybrid crops with poor stalk quality can lodge in early November and after that, the lodging can increase from 70 percent to 100 percent.
Growers need to know there is no benefit to leaving corn in the field after early November, Thomison said, because it won’t dry down much after that.
Toxins. In addition to yield losses, the longer corn is left in fields, the greater the chances for mold and ear rot development, which can lead to mycotoxin problems. Mycotoxins, such as aflatoxin, can cause animal and human health problems.
Ohio growers, however, should not be overly concerned about aflatoxin contamination this year, said Pierce Paul, an Ohio State plant pathologist with the Ohio Agricultural Research and Development Center.
He said just because an ear is infected with Aspergillus, a fungus that causes aflatoxin, does not mean aflatoxin is being produced.
Aflatoxin is only produced under certain environmental conditions, such as drought and high temperatures, Paul said.
While drought conditions did occur in some parts of the state this season, he said weather conditions have not been favorable enough to produce a major aflatoxin problem this year.
Mold growth prevention. Still, Paul said care needs to be taken to prevent accumulation of mold growth and toxins in stored grain.
To minimize the chances of mold growth, growers should earmark lodged cornfields first for harvesting.
For more information on aflatoxin, visit www.oardc.ohio-state.edu/ohiofieldcropdisease/Mycotoxins/mycopageaflatoxin.htm.