Mixed message

April 5, 2016 8:13 AM
Blog Post

The rapid spread of herbicide resistant weeds threatens the current Midwest production system. Introduction of new herbicide resistance traits will provide additional management options for resistant-prone weeds such as waterhemp, giant ragweed, and marestail; however, these systems must be used in integrated programs to delay continued evolution of herbicide resistance. The identification of 2,4-D resistant waterhemp in multiple states clearly shows that without wise use, the relief provided by these new tools will be short-lived.

Both DowSciences and Monsanto stress the need for diversified weed management programs with the Enlist and Xtend traits. Labels of the products registered for use on these crops provide detailed information on proactively managing herbicide resistance. Thus I was somewhat surprised/disappointed to find the following statement on the Enlist Duo label: “Hard to control weeds, such as Palmer amaranth, may require a total program approach . . .". It is my opinion that a 'total program approach' is required regardless of the target weed species; failure to do so will quickly put the weeds back in the driver's seat.


Bob Hartzler Professor of Agronomy

Dr. Bob Hartzler is a professor of agronomy and an extension weed specialist. He conducts research on weed biology and how it impacts the efficacy of weed management programs in corn and soybean. Dr. Hartzler also teaches undergraduate classes in weed science and weed identificatio...