Farm Horizons Farm Horizons 6/16 | Page 7

Farm Horizons • June 6, 2016 • Page 7 Managing crop pests Each year, it seems we get just the right ment practice. This gives crop producers weather conditions for a pest, insect, or time to identify and monitor pests before Dave Schwartz they exceed economic thresholds. disease, and the population of that pest Certified crop advisor explodes. Over the years, I have been called Gold Country Seed Last year, cooler, damp weather in out on many crop pest problems, and July triggered white mold infection in oftentimes, the damage had already soybeans. Hot, dry summers are ideal been done, so it was too late to justify for spider mites that feed on many types any type of rescue treatment. Economic of plants. thresholds are based on sound research, so growers know So, what can we expect for the 2016 growing season? how much crop damage can occur before action needs to It all depends on weather. We have had a nearly ideal be taken. spring for planting, with very little soil compaction, so A couple of diseases to watch for on continuous corn I would expect to see less phytopthora root rot in soy- acres are Goss’s Wilt and Northern Leaf Blight. Goss’s beans. Wilt was first identified in the state five to 10 years ago in It seems like we have experienced less strong southerly western Minnesota in a corn field under irrigation. Since winds this spring, so potato leafhoppers, which blow in then, it has spread across the state all the way into northfrom southern states, are less likely to be a problem in the west Minnesota. It does not survive well in corn/soybean first cutting of alfalfa. rotations, so is nearly always found in continuous corn. Some weather forecasts are predicting a warm, dry AuI’ve noticed more northern leaf blight the past two gust, so this may reduce the potential for diseases, but years. The fungus produces cigar-shaped lesions on lower create a more favorable environment for spider mites in leaves of plants. It’s a good idea to rotate out of corn when soybeans. either of these diseases is identified. n Scouting fields on a regular basis is a good manage-