Although there's another year to the research project, Loux says a few things are already clear to him. First, effective burcucumber management in corn requires a combination of pre-emergent and postemergent herbicide applications. Starting with a pre-emergent herbicide reduces the number and also the size of the weeds at the time of the postemergent herbicide application. Herbicides capable of doing so include Lexar, Lumax, Corvus+atrazine and Balance+atrazine. "Any of these should be much more effective for early season control in comparison to atrazine premix products," Loux says.

More importantly, it appears that the use of a postemergent herbicide treatment with both foliar and residual activity on burcucumber may be the most vital component of a management program. Callisto or Spirit, both of which have residual activity on burcucumber, provided more effective end-of-season control than bromoxynil, unless the bromoxynil was applied twice.

"We expect that results with glyphosate will be similar to bromoxynil, since both herbicides lack residual activity," Loux says.

It didn't seem to make a difference if Callisto was applied on 20- or 37-in. corn, but, Loux adds, it's possible that the later application could be more effective in a year when burcucumber emerges in great numbers in late June or July.

"We will hopefully know more about this after another year of research," he says.

Loux first reported findings from the study in the Crop Observation and Recommendation Network (CORN) newsletter, produced by Ohio State's Agronomics Crop Team, a multidisciplinary group of faculty members and educators with OSU Extension and OARDC. The newsletter is available online, where readers can sign up for a free e-mail subscription.