Managing herbicide resistant weeds

Farm Forum

The leadership of the CCA (Certified Crop Advisor) program asked the members to take part in an online survey on the issue of herbicide-resistant weeds. Nearly 1,700 people responded to questions about the resistant weed pressure in their areas, the most effective management tools and approaches, and the obstacles to achieving wider adoption of best management practices (BMPs) for managing herbicide resistance.

The respondents came from a variety of backgrounds, with roughly 75% being retail agronomists, independent agronomists and retail sales managers. The remaining respondents were made up of manufacturer representatives, wholesale representatives, Extension and university, production agriculture, and government employees. The largest number of responses came from the north central United States.

Forty-nine % of respondents reported a moderate level of resistant weed pressure in their regions, 34% reported minimal, 12% heavy, 3% none, and 2% an epidemic level. When asked what they felt the most effective tool was in the fight against resistant weeds, 52% of the CCA’s said different chemical modes of action. Twenty-four % listed crop rotation, 8% tillage, 8% Best Management Practices (BMP’s), 4% education, 3% new chemical solutions, and 1% seed.

Herbicide resistant crops have been available for a number of years and enjoyed a wide level of adoption. Nearly 60% of respondents thought they were an extension of the problem, 25% thought they were a solution to the problem, 10% considered them a tool, but not the solution, 3% considered them a short-term solution, and 4% both a solution and extension to the problem.

When asked what they thought the next “silver bullet” in the fight against herbicide resistant weeds will come from, 57% indicated knowledge and implementation of BMP’s. Nineteen % of respondents said there is no silver bullet, 9% suggested chemical solutions, 7% thought traits, 2% reported grower innovations, and 1% suggested mechanical solutions. Two % chose a combination of these choices, another 2% chose all of these solutions, and 1% selected other.

As indicated in the second paragraph, the vast majority of respondents were in some type of advisory role relative to managing herbicide resistant weeds and were asked what describes their growers’ actions/thoughts when considering adoption of weed resistant BMP’s. Forty % said growers would only adopt BMP’s if resistant weeds became a problem in their fields. Another 30% responded that their growers were at least trying BMPs or were “jumping right in” because it was the right thing to do. Twenty-five % stated that their growers were open to BMPs, but were also concerned about the cost and effort of implementing them. Three % thought their growers would adopt BMP’s only if their neighbors did too, and 5% chose other options.

Herbicide resistant weeds is a very real problem, and becoming worse. Visit for more information on managing them.