There are some ugly mycotoxins such as ear rot and aflatoxin waiting to break out in corn fields under the right conditions. It's something that bears watching at harvest.
Drought has already stressed the corn crop in the upper Southeast. Seasonal, late summer, early fall rains could hammer corn and silage quality.
“We're ripe for a big outbreak of mycotoxins,” says Ronnie W. Heiniger, North Carolina State University Extension corn specialist. “Rain and high humidity at harvest could cause serious problems for our corn producers.”
Heiniger explains that a drought increases nitrate levels in corn and silage crops and that rain following a drought increases mycotoxin potential.
To head off the problem, Heiniger recommends checking corn fields and coming up with a harvest plan. “If it looks like there's going to be a problem in the field, go ahead and harvest as early as you can.”
Scratch the tip of a kernel of corn to see if it's black on the band. “The black layer signifies that the corn growth has terminated — it kind of acts like a stopper on a bottle to stop the flow of nutrients to the kernel,” Heiniger says.
Speaking at the Blackland Farm Managers Summer Tour in Plymouth, N.C., Heiniger said that black layer occurs at moisture levels between 36 percent to 34 percent. Farmers looking to avoid mycotoxins can harvest corn at a moisture of 26 percent to 24 percent and dry down to moisture levels below 18 percent where mycotoxins will not form.
“Where you see you may have a problem, go to those fields, look at it and make a decision about what to do,” in order to reduce the risk of mycotoxins in the corn and discounts or rejections at the elevator, Heiniger says.