Do you think you have glyphosate-resistant weeds?

Dr. Tom Davis (UNH Professor of Plant Biology/Genetics) would like to study evolved resistance to glyphosate-containing herbicides (i.e., Roundup). He would like to document the occurrence of glyphosate-resistant weeds, if any, on farms, dairies, orchards, and other managed environments in the New Hampshire region. His goal is to study the evolutionary mechanisms involved in the emergence of glyphosate-resistant weeds of any type, but he’s specifically interested in lambsquarters (Chenopodium species) and pigweed (Amaranthus species). 

If you as a grower have any reason to believe that you have seen any glyphosate-resistant weeds on or around your farm, and/or if you are concerned about the potential for such resistance to arise, please reach out to Tom Davis (, or 603-862-3217). All such communications will be treated as confidential. The goal of the study is to learn how glyphosate-resistant weeds arise, and thereby to help figure out how to minimize the likelihood of this outcome.