Fall weed control is not a new concept for many farmers, but the need for the applications has shifted. Aaron Hager, Extension weed specialist for the University of Illinois says when he started working for the University, fall applications targeted perennial weeds. Today, the need to target perennials has dwindled and farmers have shifted weed control towards winter annuals.
“The reason we do this is because in the fall these weeds are, generally speaking, much smaller than they will be the following spring when we try to do a burn-down application in front of a no-till planting scenario,” says Hager. “So, we have the advantage in the fall of treating smaller weeds. We can adjust the herbicides that we need to use quite easily, without any concerns for crop injury, for example, and many times, we can be more consistent in the control of the winter annuals in the fall compared within the spring.”
Hager adds that controlling the winter annuals before they flower in the spring will reduce the among of weed seeds from those species that go back into the soil for the next year.