Earlier this fall, Syngenta Crop Protection initiated an educational and promotional campaign built around a herbicide resistance management strategy that they’ve named 2-1-2. The numeric code (below) describes an approach in which no more than two applications of glyphosate are made to one field within a 2-year period.

This herbicide resistance management approach is different than those typically recommended by weed scientists at most land-grant universities. As a result, Ohio State University weed scientist Mark Loux and Iowa State University weed scientist Bob Hartzler recently expressed their views on the merits of the 2-1-2 strategy in the following dialogue that appeared on the Iowa State University agronomy Web site.

Loux:

This is part of Syngenta’s continuing quest to be perceived as taking the high road on glyphosate stewardship. They should be acknowledged for maintaining awareness of these resistance issues, but they’ve tried to oversimplify a fairly complex issue.

Taken at face value, the 2-1-2 strategy doesn’t work. Using this strategy, a grower could make two glyphosate applications in Roundup Ready soybeans, and then use herbicides other than glyphosate in corn the following year, and so forth. Unfortunately, producers in Ohio developed glyphosate-resistant horseweed (marestail) populations by following this program.

Hartzler:

One of my mottos is “Simple is good,” and that’s why I like this approach. Weed scientists in the north central region developed an extension bulletin on herbicide resistance back when ALS resistance was first emerging as a problem. To keep everyone happy, they ended up with a list of…