The upper Midwest has experienced a cool, wet spring thus far. Most of us were left 40-80 heat units short of April’s 30-year average while receiving 100 to 200 percent of the month’s average rainfall. Some areas exceeded 200 percent of average rainfall! Watching the rain out the window can lure anyone into a flurry of stressful “what-if” scenarios, but the Dairyland Seed Agronomy Team wants everyone to focus on a few pest issues that we are anticipating with the compromised field preparation across the countryside.
Many common field weeds are getting a head start on the crop. Annual and biennial broadleaf weeds are coming on first and could be nearing the size limits of herbicide labels by the time applications can be made. We are all familiar with the “start clean, stay clean” mantra. To achieve this:
Increased weed pressure can compound insect pressure as well. Pay special attention to any alfalfa or small grain fields being taken out this spring; they can be insect hot beds. Black cutworm moths have been arriving in the upper Midwest for the better part of a month.
Armyworm flights have also been observed during the past month in the Midwest. Treatments are warranted if larvae are less than 1 inch long and two or more are observed on at least 25 percent of plants OR 1 or more are observed on 75 percent of plants. (Jensen, et al., 2017)
Ostlie, K. and Potter, B. (2017). Black Cutworm. University of Minnesota Extension-Integrated Pest Management.
Jenson, B., Liesch, P., Nice, G., Renz, M., Smith, D. (2017). A3646 Pest Management in Wisconsin Field Crops. University of Wisconsin Extension, p65.