By Clint Schroeder – OSU Extension Allen County
OSU Extension will be monitoring for Western Bean Cutworm (WBC) moths again during the 2020 growing season. Western bean cutworm moths overwinter in the soil and emerge as adults in late June or early July. Adults then mate and lay eggs in clusters on the top surface of the upper third of a corn plant. The eggs require five to seven days to develop, during which time the egg color changes to tan and then to purple immediately before hatching. As the eggs hatch the larvae will look to feed on the exposed tassels and then make their way into the husks to feed on the developing corn ear. Scouting is critical as larvae that hatch prior to tasseling have a low survival rate, and larvae that have entered the husk will be protected from insecticide applications.
Western Bean Cutworm Moth
By Dr. Mark Loux OSU Weed Science
According to our network of sources, the effectiveness of new soybean trait systems has some growers once again thinking about omitting preemergence residual herbicides from their weed management programs. Some people apparently need to learn the same lessons over and over again. Having gone through this once in the early 2000’s when Roundup Ready soybeans had taken over and we all sprayed only glyphosate all day every day, we think we’re pretty sure where it leads. We’re sensitive to concerns about the cost of production, but the cost-benefit analysis for residual herbicides is way in the positive column. We’re not the ones who ultimately have to convince growers to keep using residual herbicides, and we respect those of you who do have to fight this battle. Back in the first round of this when we were advocating for use of residuals, while the developers of RR soybeans were undermining us and telling everyone that residuals would reduce yield etc, we used to have people tell us “My agronomist/salesman is recommending that I use residuals, but I think he/she is just trying to get more money out of me”. Our response at that time of course was “no pretty sure he/she is just trying save your **** and make sure you control your weeds so that your whole farm isn’t one big infestation of glyphosate-resistant marestail.” And that answer probably works today too – maybe substituting waterhemp for marestail.