Preserve glyphosate to protect the value of no-till

Published on: 18:13PM Jan 19, 2010
Chuck Foresman

I recently had the opportunity to talk to several hundred of the most dedicated no-till farmers in the country at the 2010 National No-Till Conference. They are an innovative group, and because of their commitment to no-till farming, they feel the threat of spreading glyphosate resistance keenly. 
These guys rely on herbicides to control weeds, and glyphosate is a critical tool for their operations. However, as glyphosate-resistant weeds like horseweed (marestail) spread, they are struggling to protect their yields without reverting to iron to control weeds.

My recommendations in soybeans included starting with a clean seedbed with a burndown herbicide that has an alternative mode of action, choose early pre-plant or pre-emerge herbicides with residual and two modes of action, and use glyphosate in-season with another mode of action. This type of program will help preserve glyphosate, and, by extension, the value of no-till and conservation-till systems.
No residual vs. pre-emergence herbicide
One last note – glyphosate resistance seems to initially rear its head in fields that are not rotated to other crops, enabling more herbicide diversity.  So keep a close eye on fields planted to the same crop year after year.