Minnesota Crop News

Angie Peltier, UMN Extension crops educator, Northwest Research & Outreach Center, Jeff Vetsch, UMN research supervisor, Southern Research & Outreach Center and Axel Garcia y Garcia, UMN Extension, sustainable cropping systems specialist, Southwest Research & Outreach Center Cereal rye cover crop seeded at 50 lb/a in the fall and terminated at planting. Photo: Liz Stahl, UMN Extension 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 Liz Stahl. Note : Join us this week on Wednesday when we welcome Dr. Dean Malvick, Extension plant pathologist, and Brad Carlson, Extension educator, to discuss What to expect after heavy June rains in terms of crop diseases and nutrient management.  With Cover Crops, Flexibility is a Must Liz visited with the guests who had just presented some of their research...

By Larry VanLieshout, MDA Research Scientist, Tana Haugen-Brown, Sally Raymond, and Jolene Warnke, UMN Pesticide Safety and Environmental Education Extension educators Figure 1. FieldWatch map. Protecting your neighbors’ crops and beehives from pesticide drift starts with knowing where they are located. FieldCheck , from FieldWatch® Inc ., is a voluntary online program designed to help pesticide applicators view potentially sensitive crops and beehives in their area so they can take extra precautions when making pesticide applications. To reduce potential offsite injury due to pesticide drift, follow all label requirements. In addition, scout the surrounding area and check the FieldWatch Map (Figure 1) prior to application to see if there are pesticide sensitive sites in the area. Zoom in on areas of interest to see the field borders (Figure 2). Selecting a pin on the FieldWatch map brings up additional crop or apiary information and contact information for that producer (Figure ...

Robert Koch, Extension Entomologist We have observed soybean aphids colonizing soybean fields over the last couple weeks. The infestation levels have been very low in all fields we have seen, which is typical for this time of year. So, please do not rush out to spray your fields after reading this. Instead, the next couple weeks will be a good time to begin your soybean aphid scouting program. In the early season, prioritize your scouting efforts to smaller fields with wooded borders, especially those in areas with lots of buckthorn (the plant on which soybean aphids spend the winter), and early-planted fields. While scouting, keep an eye out for lady beetles and ants on soybean plants, because these are early indicators of the presence of soybean aphids. Infested fields should be scouted on a regular basis. To determine when to spray a field with insecticide for soybean aphid, use the economic threshold of 250 aphids per plant, with most of the plants infested, and aphid populations ...

This week on Advancing Nitrogen Smart , Melissa Wilson and Brad Carlson talk about manure sampling and testing. What are some sampling guidelines to be aware of in Minnesota? How variable is nitrogen in one type of manure, and then from type to type? How could changes to a farmer's overall operation affect manure nutrient content? How should manure samples be stored? Safety is huge - what do farmers need to know about staying safe when working with manure? Oh, and how do you prevent sample jars from exploding in the mail? This, and lots of manure info on today's show.  TRANSCRIPT Guests: Brad Carlson, Extension educator (Mankato) Melissa Wilson, Extension manure nutrient management specialist (St. Paul) Additional resources: 2025 Certified Manure Testing Laboratories Nitrogen availability of different manure types: What we know and what we are researching Introducing ManureDB: A new way to view manure variability and trends Manure management Manure Land Application: Minim...

Anthony Hanson (hans4022@umn.edu), Extension Educator - Integrated Pest Management It's been a relatively slow alfalfa weevil season compared to previous years, though some reports of high population fields have trickled in during June. Most are mature larvae (i.e., fourth instar) that should cease feeding soon, but there are still some younger larvae present in samples (Fig. 1). Figure 1. Alfalfa weevil larvae collected from Morris, MN on June 17, 2025. Older third and fourth instar larvae are bright green, while first and second instars are smaller and pale yellow. Photo: Anthony Hanson.   While I've been finding larvae regularly in west-central MN, I haven't seen large enough populations that quite reach an economic threshold and financially justify a insecticide application. This has been the case this year across the state when I've checked in with other extension educators and crop professionals. I would not be surprised if there are scattered fields that have re...

Sachin Dhanda, Former weed science postdoctoral researcher, Sithin Mathew, Weed science graduate student, and Debalin Sarangi, Extension weed scientist Soybean field treated with postemergence Cobra  herbicide (within the label cutoff) showing  temporary leaf injury. Photo: Sithin Mathew) As postemergence herbicide spraying is ongoing in Minnesota this week, this is a reminder that all the applications should follow the growth stage cutoffs specified on herbicide labels for postemergence applications and to comply with the preharvest interval (PHI) which is legally required. The PHI represents the minimum time between the last herbicide application and the crop harvest. The restrictions are in place to prevent potential crop injury, herbicide carryover, environmental or food safety issues, and other concerns. If tank mixing two or more herbicides, the cutoff is determined by the most restrictive labels. Always consult herbicide labels prior to application to ensure ...

Sachin Dhanda, Former weed science postdoctoral researcher, Sithin Mathew,  Weed science graduate student, and Debalin Sarangi, Extension weed scientist Corn field planted in mid-May requires  postemergence herbicides for weed control. Photo: Debalin Sarangi Herbicide labels typically specify growth stage or crop height cutoffs (whichever comes first) for herbicide application, and the preharvest intervals (PHI) indicate the minimum time required between the last herbicide application and crop harvest. The restrictions are crucial to prevent potential crop injury, herbicide carryover, environmental or food safety issues, and other potential concerns. When tank mixing herbicides, the most restrictive label determines the cutoff. Always consult herbicide labels before application to ensure compliance. Below is an updated table (as of June 17, 2025) summarizing field corn growth stage or height cutoffs and PHI for commonly used postemergence herbicides. The growth ...

Diseases Last week, the scouts continued to find a few fields with tanspot at low incidence and severity.  Since last Thursday, widespread rains across much of Minnesota have allowed for much longer leaf wetness periods. Only the Red River Valley north of Hwy 200 continues to miss out on any measurable amounts of rain.  Consequently, the conditions for small grain diseases, including FHB, to develop are much more favorable for most. This means that, compared to a week ago, the disease management/fungicide recommendations are changing. For oats and barley that will be reaching Feekes 10.5 (or fully headed), switch to a fungicide labeled for the suppression of FHB, as the risk forecast for the remainder of the week remains moderate to high across all but the NW and SW corners of the state. Likewise, apply a fungicide labeled for the suppression of FHB in wheat when the crop reaches Feekes 10.51 (or beginning of anthesis). Choose one of the premium fungicide products when your ...

By Neal Kittelson, MDA, reviewed by Tana Haugen-Brown, UMN Pesticide Safety and Environmental Education Extension educator, Sally Raymond, UMN Pesticide Safety and Environmental Education Extension educator, and Jolene Warnke, UMN Pesticide Safety and Environmental Education Extension educator You may have noticed lately more references to the Endangered Species Act and pesticide labels. Why now? The Environmental Protection Agency (EPA) has developed new “strategies” for how they are handling its obligations under the Endangered Species Act (ESA). The EPA released the finalized Herbicide Strategy on August 20, 2024, and the Insecticide Strategy on April 29, 2025. The finalization of these strategies will result in several changes to pesticide labels that users will need to be aware of before making applications. Updates to pesticide labels are being implemented through the pesticide registration process and will take considerable time to fully implement, so be sure to fully read y...

By: Tarah Young, Extension educator, Dan Kaiser, Extension nutrient management specialist, & Jochum Wiersma, Extension small grains specialist Hybrid winter rye is gaining popularity in Minnesota for its strong yield potential and adaptability. A multi-year study across Minnesota shows that hybrid winter rye can achieve high grain yields with significantly less nitrogen than previously recommended—especially when most of it is applied in the spring. Strategic nitrogen management not only boosts yield but can also reduce lodging and nitrogen loss risks. Background Hybrid winter rye is gaining traction in Minnesota thanks to its hardiness and potential for high grain yields. This winter cereal offers many advantages over traditional open-pollinated varieties. These hybrids produce: Higher yields (25–40% more than open-pollinated rye) More tillers per plant (2 to 4 times more) Lower risk of ergot due to improved pollination Shorter, sturdier plants that resist lodging better These tra...

Dr. Rob Proulx at North Dakota State University updated the recommendations for ground application of fungicides to combat Fusarium Head Blight.  The extension bulletin detailing the new recommendations can be found here .  The long and the short of the updated recommendations is to use TeeJet's new asymmetric dual spray nozzles (Photo 1). These nozzles were specifically designed to spray fungicides at anthesis in cereals.  This new style allows for ground speeds between 10 to 15 mph without sacrificing control when using a spray volume between 10 and 20 gallons per acre and pressure yielding a coarse droplet size.  For example, a sprayer equipped with AI3070-03VP nozzles will deliver a coarse droplet size at 60 to 80 psi to between 11 and 12.5 gpa at 10 mph.  When equipped with AI3037-04Vp nozzles, that same sprayer can travel up to 15 mph at 70 psi to deliver 10 gpa. Photo 1 - TeeJet  AI3070-03VP nozzle (Photo credit: TeeJet Technologies)

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...