By Mark Loux, OSU Extension

We have been screening a random sample of waterhemp populations for herbicide resistance over the past two years.  Herbicides used on the screen include mesotrione, atrazine, 2,4-D, fomesafen, and metolachlor.  Results of our research show that it’s possible for Ohio waterhemp populations to have some level of resistance to one, several, or all of these herbicides.  Glyphosate is not included because we assume almost all populations are already resistant to this.  We are also part of a regional project that has been screening for dicamba and glufosinate resistance with populations that we supply, although none has been identified to date. Continue reading →