GOSHEN, Ind. — I spoke to a couple of growers last week who commented about the condition of the remaining corn standing in their fields. Many stalks appear thin and brittle, and ears are vulnerable to drop to the ground. Their fear is that additional moisture along with wind storms could take a further toll on what has been a tough year.
Grain losses can be divided into 3 categories: pre harvest loss, gathering losses and machine losses. Just 2 kernels in a square foot equal one bushel of loss per acre. One ear (approximately ¾ pound of grain) in each 1/100 of an acre is the equivalent of one bushel per acre.
Not only do we think about the loss of grain that cannot be sold, we can also think about the effect of the volunteer corn on next year’s crops. The University of Minnesota did a study showing the effects of volunteer corn populations ranging from 800 to 13,000 plants per acre. The yield losses ranged from 0 to 54% in soybeans and 0 to 13% in corn.
Nebraska studies showed that clumps of volunteer corn emerging from dropped ears are more competitive than individual plants. They found that 3500 clumps of corn per area reduced yield 40% in soybeans, while the same number of individual plants cut yields 10%.
Most of the hybrid corn today has traits for insect resistance built in. Having a large population of volunteer corn essentially nullifies the effect of crop rotation. The volunteer plants also contain sub-lethal levels of the Bt toxin, which has the potential to hasten the development of resistance to Bt traits.
What should you do if you have a lot of ear and kernel loss? In the “old days,” farmers would turn cattle or hogs out to harvest the lost grain. These days, many fields do not have fences, so that option is often not available. Allowing the seed to stay on the soil surface over winter may reduce the population the following spring. Some of the seed will germinate and die in the cold, some seed will be eaten by deer or mice, and some will rot over the winter.
In the spring, volunteer corn is much easier to control with herbicides in soybeans than in corn because there are more options to control grass. Be aware that Liberty can control volunteer corn, but only if the hybrid corn planted this year was not LibertyLink resistant.
— Purdue Extension Elkhart County
For more news from Indiana, click here.