Date of this Version
Chapter in 2013 Crop Production Clinic Proceedings, University of Nebraska-Lincoln Extension, Institute of Agriculture and Natural Resources, pp. 14-15.
As most dryland corn producers are aware, the dry and hot growing season in 2012 resulted in reduced corn yields with moderately lower test weights. Along with the reduced test weights are concerns about potential mycotoxin contamination in the drought-stressed grain.
The only way to know for sure if there are mycotoxins in your grain and which specific mycotoxins are present is to collect representative grain samples and have them tested by a certified laboratory.
Many species of fungi can cause ear rot diseases and molding of grain. Most of these fungi become associated with the grain in the field but may continue to grow and reproduce if grain is stored under favorable conditions of moisture and temperature in the bin.
Harvested corn is NOT necessarily safer in the bin than in the field with regard to maintaining grain quality. If there was a problem with ear rot diseases in the corn in the field, there will likely be grain mold problems in the bin. Even under the best storage conditions, grain mold fungi are likely to continue to grow in the bin, where some can also produce mycotoxins. Under these conditions, it is important to cool and dry harvested corn as quickly as possible – preferably within 48 hours of harvest. It is NOT recommended to store infected grain, particularly for extended periods of time. In addition, grain that is damaged during or after harvest, such as during handling or storage by insects or other mechanical means, is much more prone to fungal infection by grain molds.
Ear rot diseases and grain molds can lead to substantial reductions in grain quality that can ultimately cost producers who may be penalized at elevators or by loss of feed quality.