Minnesota Crop News

Jamison Scholer, MDA Research Scientist, Jolene Warnke, UMN Pesticide Safety and Environmental Education Extension educator, and Tana Haugen-Brown, UMN Pesticide Safety and Environmental Education Extension educator Responding to pest threats that emerge in your crop fields and supporting beneficial insects (predators and pollinators) living around your farm doesn’t need to be mutually exclusive. Thoughtful consideration of pesticide selection, use timing, and application method can give you the benefits of both. Supporting beneficial insects that call your lands home means more tools in your arsenal to maximize yields and minimize pesticide inputs when economic thresholds are followed. For example, in soybean, pollinator visitation can increase yield in many nectar producing varieties 1, 2 . Maintaining untreated, uncultivated land around crop fields, such as field margins, ditches, conservation strips, etc., help support pollinators and predators that feed on crop pests and may reduc...

Angie Peltier and Ryan Miller, UMN Extension crops educators and Debalin Sarangi, UMN Extension weed scientist The following information was provided during a 2025 Strategic Farming: Field Notes session. Use your preferred podcasting platform or listen online to a podcast of this Field Notes session hosted by UMN Extension crops educator Eric Yu. Weed growth progressing While recent cool and cloudy weather may have temporarily delayed both crop and weed development, folks that were able to get their crops planted in mid-May may now be seeing 4-6 inch tall giant ragweed plants. Waterhemp, the prolific and multiple herbicide-resistant bane of many Minnesota agronomic crop producers, and lambsquarters are now also reaching 4 inches in height. This information is the equivalent of a giant banner reading, “if you didn’t start post-emergence herbicide applications yesterday, start them today.” Depending on your location and planting dates, timely rains may have come after planting and pre-e...

Rear Admiral Grace M. Hopper, the grandmother of the computer age, once said that one accurate measurement was worth a thousand opinions. Plant pathologists took Grace’s words to heart and have developed many disease management decision support systems, including ones for the economically important diseases in wheat and barley. Leaf Wetness Duration Period is Key  Many of these disease management decision-support systems use weather data to calculate leaf wetness duration periods (the consecutive number of hours with free water on the plant’s (leaf) surface) and compare that value with the minimum length of time needed for a fungal spore or bacterium to germinate and grow/penetrate the plant's epidermis (skin). Why Not Look for Fungal Spores?  Most systems DO NOT measure the presence of the fungal spores. This may seem counterintuitive or even negligent, but it is not as disastrous as you might think. While it is technically feasible to sample air for spores, it is extremely ...

Dr. Fei Yang, University of Minnesota, Extension corn entomologist, and Dr. Yucheng Wang, University of Minnesota, Research Specialist Peak rootworm hatch typically occurs in June across the Midwest, making this the critical period for growers to begin scouting for larvae and evaluating early feeding damage. Recent updates from Iowa State University indicate that corn rootworm egg hatch has reached its critical benchmark in southern Iowa this week ( Hodgson and Dean 2025). Given the similar climatic patterns across the Upper Midwest, corn rootworm egg hatch in southern Minnesota is likely approaching a similar peak window, slightly behind Iowa peak (Figure 1). While lightning bug activity is sometimes used as a visual cue for corn rootworm hatch, it is far less reliable than soil temperature-based degree day models. Development of corn rootworm eggs is driven by soil temperature and tracked using soil-based growing degree days (GDDs), calculated from January 1 with a base tempera...

Register now for the Weed Science Field Day on Thursday, July 10, 2025, from 8:30 a.m. to 1:00 p.m. at the Rosemount Research and Outreach Center at Rosemount, MN. Growers, crop consultants, agronomists, and other stakeholders are invited to tour several research-plot demonstrations on a variety of timely topics in corn and soybean weed management: Herbicide-resistant weed management New herbicides and technology Cover crops Weed detection using remote sensing Registration Thanks to the generous support of our sponsors, there is no cost to attend the Field Day and lunch is included. However, pre-registration is recommended. Register online by 5 p.m. on July 9. Register online   or scan this QR code with your cell phone: Directions to the Field Day The Rosemount Research and Outreach Center is located off of 160th St. (CR 46) between MN-Hwys 3 and 52. From MN Hwy 3, turn east on 170th St. W. After 1.8 miles, turn left (north) on Arkansas Ave. and park by the equipment shed. GPS...

Welcome to another season of weekly small grains disease and pest updates.  This first issue should have gone out last Friday after the scouts completed their first week roaming the Minnesota countryside looking for diseases and pests. Unfortunately, a technical glitch prevented me from seeing the tally of their work. So....here it goes. Diseases Overall, the disease situation is relatively quiet. All indications are that stripe and leaf rust pressure in Kansas and Nebraska is relatively low. That means that the number of spores traveling north will also be low. This, in combination with the unfavorable weather conditions (as indicated by the NDSU disease risk models), suggests that things will continue to be quiet for those two diseases.   To date, the weather has been most favorable for tan spot.  The scouts found a few tan spot lesions in three of the sixty fields in west central and northwest Minnesota. The previous crop was spring wheat in each instance.  C...