Iowa Survey: Weed Resistance Seen as Daunting Problem — DTN

    A growing number of farmers say they see weed resistance becoming a problem on their land and may feel powerless to combat what they see as a continuous evolution, a new Iowa Farm and Rural Life poll found.

    A number of technology developers have stepped up efforts in the past decade to commercialize seed and chemical combinations to overcome weed resistance, but farmers indicated in their answers to those conducting the survey that they’re unsure where the battle will lead.

    The poll is an annual survey on issues of importance to farmers. Iowa State University Extension and Outreach, the Iowa Agriculture and Home Economics Experiment Station, the Iowa Department of Agriculture and Land Stewardship, and the Iowa Agricultural Statistics Service are partners in the Farm Poll.

    “A central finding of this research is that many Iowa farmers believe that they have identified pesticide resistance on the land they farm, and most are concerned that herbicide-resistant weeds and Bt-resistant insects will become a problem in the areas where they farm,” the poll found. “They also understand that the way farmers use pest management technologies has a major impact on the rate of resistance evolution. Further, they view resistance management as a community problem involving multiple stakeholders. However, most Iowa farmers also seem to view pest management as a never-ending treadmill cycle of resistance evolution.

    “This perspective is concerning, because it implies that many farmers feel somewhat powerless to cope with evolution of resistance. In fact, the rate at which pests evolve resistance can be slowed significantly through widespread, coordinated pest management practices and strategies. However, such coordinated action is lacking, especially in the area of weed management.”

    The good news, according to the poll, is that most farmers surveyed are ready to take necessary actions to overcome weed resistance. The poll shows farmers see themselves as most responsible for resistance management.

    “This makes sense, because the most effective resistance management strategies are those that can be implemented at the farm-level, such as crop rotation, rotation of pesticide mechanisms of action, and using other integrated pest management practices,” according to the pollsters. “However, they also ascribe responsibility to other key stakeholders, such as pesticide manufacturers, university scientists, and commercial pesticide applicators. This suggests that they believe that efforts to manage the evolution of resistance in pests should be a community effort among stakeholders, and that they may be open to working on coordinated, collaborative pest management approaches.”

    Many experts have pointed to the need for the development of a coordinated resistance management strategy involving private sector firms, commodity groups, farmers, farmer associations, universities and government agencies.

    The latest poll posed two sets of questions about the evolution of pesticide resistance. The questions were developed in consultation with Iowa State University agronomists, entomologists, plant pathologists and weed scientists.

    One question set measured general perspectives on pest resistance management. A second question evaluated farmer beliefs about the degree to which different stakeholders are responsible for resistance management actions. Questions focused on whom farmers trust for information on pest management, and to what degree they depend on professional advisers to help make pest management decisions.

    The 2013 and 2014 surveys asked farmers who planted corn and/or soybeans the previous year if they believed they had herbicide-resistant weeds or Bt-resistant insects in any of the fields they farmed.

    According to the poll results, the 2013 survey listed several types of herbicides and asked farmers if they had weeds that were resistant to them in the 2012 growing season.

    Thirty-two percent of farmers said they believed they had encountered weeds that were resistant to glyphosate. Fourteen percent reported they had weeds that were resistant to ALS inhibitors.

    The 2014 Farm Poll asked about Bt-resistant corn rootworm. The question was, “In 2013, did you identify Bt-resistant corn rootworm in any of your fields?” Twelve percent of farmers who planted corn reported they had encountered Bt-resistant corn rootworm.

    Of the six groups provided, farmers rated themselves as most responsible for resistance management, with 94% indicating that farmers bear at least some responsibility for managing resistance. Farmers ascribed similar levels of responsibility to pesticide manufacturers.

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