By Dr. Mark Loux, Ohio State University Extension Weed Specialist, Adapted from C.O.R.N. 2021-08
Dandelion seems to be on the increase in some fields, as we noted in a video last summer and CORN article last fall. Fall is the optimum time of year to reduce dandelion populations with herbicides, so we expect them to become more of a problem in fields that are not treated in the fall at least occasionally. If history is any indicator, other causes can include oversimplification of herbicide programs in soybeans, omission of residual herbicides, and delaying burndown herbicides until later in spring. All of these occurred during the first few years of RoundupReady soybeans, and we had some dense stands of dandelions that developed in late 1990’s. We again have some very effective weed management platforms for soybeans, and the possibility of the same happening. In addition, while POST applications of glufosinate have broad-spectrum activity on annual weeds, they are not that effective on dandelion and other perennials, which can allow some of these weeds to get more of a foothold.