Testing for Herbicide Resistance: A Look at Montana State’s Options

The Weed Science Lab at MSU offers molecular tests that can determine the type of herbicide resistance occurring in a weed population. (Photo credit: Claudio Rubione, GROW)

When a herbicide stops killing a weed, farmers are left with a lot of questions. Is it herbicide resistance? Will other herbicides still work against this weed? 

Here to answer those questions is the Weed Science Lab at Montana State University’s Southern Ag Research Center. Led by MSU weed scientist, Dr. Lovreet Shergill, the lab offers a range of herbicide-resistance testing that gives growers detailed genetic information about the extent of the problem they may be facing in their fields. 

Kochia seedlings await testing. (Photo credit: Claudio Rubione, GROW)

Many universities offer traditional whole-plant dose response assays, where researchers collect seed from a suspicious plant, grow the weed out and then spray it with varying doses of a herbicide to see how it responds. But Dr. Shergill’s lab can go a step further and run molecular tests that can determine the exact type of herbicide resistance, such as target-site resistance or metabolic resistance. Knowing which type of resistance is in your field can have major management implications, which makes the lab a valuable asset to Montana growers, Dr. Shergill notes. 

Watch the video below for an in-depth look at what the Weed Science lab does and how target-site and metabolic resistance work:

Read more about herbicide resistance from GROW here and here.

Video by Claudio Rubione, GROW; feature and header photos by Het Desai, MSU; text by Emily Unglesbee, GROW