Reports of flooded corn are coming in from around Kentucky. Corn survival is dependent on the crop stage, the depth of flooding, the duration of flooding and the soil type in the field as well as other factors. The following are some key points to corn survival after flooding.

Corn in most fields across the state displayed nitrogen (N) deficiency before black layer was reached. Those losses were expected this season as we experience more rain. Normally, we expect yield losses to occur when the corn crop runs low on N before the seeds are done developing on the cob. However, walking some of these fields reveals that corn yields should be very good despite the apparent lack of N.

Corn grain can be naturally contaminated by mycotoxins, natural toxins produced by fungi.  Though most Kentucky corn crops are free of mycotoxins, fumonisins are the most common threat.

Aflatoxins are potent, naturally occurring toxins that sometimes develop in corn and certain other crops. Aflatoxins are also among the most carcinogenic substances known. There are well-defined limits on how much aflatoxin is allowable in corn, based on the intended end use.

Pre-harvest contamination of corn with fumonisins is a possibility in some lots of this year’s Kentucky corn crop. Fumonisins are a family of mycotoxins produced by the fungus that causes Fusarium ear rot.

Aflatoxins are showing up in occasional lots of harvested corn from this season’s crop. Aflatoxins metabolites of the fungus Aspergillus flavus, are potent toxins and carcinogens in animals, and may also be human carcinogens. Aflatoxins are probably the most well-known mycotoxins, because they have long been regulated by the US Food and Drug Administration.