By now, you have probably heard horror stories about corn fields that resemble golf courses, abandoned cotton fields choked with pigweed and waterhemp so thick you can barely see soybeans. Weed control has become more than worrisome. "The worst may be yet to come if growers can’t accept the changes necessary to keep herbicide tools viable," says Kevin Bradley, University of Missouri Extension weed specialist. "Unfortunately, it seems to take an outbreak of resistance to change habits."
It sounds almost old-school, but weed scientists agree that the time has come to go back to the basics. Think of it as devising an integrated approach that uses multiple practices to manage weeds rather than just kill them.
Bryan Young, a Southern Illinois University weed scientist, says weeds will win if farmers continuously use a specific herbicide, cropping pattern or cultural practice. Weed warriors practice diversity.
"Glyphosate made life easy. Now we must learn how to farm in a manner that attempts to preserve all herbicide technologies," Young says. Use these tips:
- Develop an integrated weed management system that includes herbicides with multiple sites of action and uses non-chemical weed control tactics where practical.
- Reduce early weed competition with burndown and/or pre-emergence applications of a residual herbicide.
- Scout regularly to respond to weed population changes.
- Use crop rotation to diversify herbicides.
- Rotate herbicide-tolerant traits or use herbicide-tolerant stacks to alternate nonselective and selective herbicides.
- Rotate herbicide site of action and use multiple sites of action to reduce selection pressure.
- Use full herbicide rates. Follow label directions and play close attention to rate and timing.
- March 2011