Minnesota Crop News

Phyllis Bongard, Educational content development and communications specialist, and Dean Malvick, Extension plant pathologist While some crop disease has been reported, most corn and soybean diseases are still in the early stages of development. Most of the diseases that cause significant issues may start appearing in the next week or two. To help know what to watch for, Dr. Dean Malvick discussed several corn and soybean diseases, conditions that favor them, and their management options in the July 23rd Strategic Farming: Field Notes episode. Soybean diseases White mold White mold, a potentially damaging disease, is favored by rain during the flowering stage. However, it prefers cool temperatures for development and while there have been a few cool nights, the warm temperatures we’ve been experiencing may slow its progression. Watch for this disease, especially if cool weather and more rain is in the forecast. Cultural practices that speed canopy closure, such as planting in narrow r...

By: Vasudha Sharma, Extension irrigation specialist As we move through this growing season, one question we often hear is: “How are we doing this year compared to normal?” While each season brings its own set of challenges, comparing this year’s crop evapotranspiration (ET) and atmospheric demand to long-term averages provides critical insight into irrigation timing, water availability, and crop stress risk. Reference Evapotranspiration (ET o ) or Atmospheric Demand Let’s begin with an overview of atmospheric demand, also known as reference evapotranspiration. Reference evapotranspiration (ET o ) is a fundamental metric in agriculture used to estimate the atmospheric demand for water from a well-watered reference crop, usually grass or alfalfa. It reflects how much water a crop would require to grow optimally under ideal soil moisture conditions. ET o incorporates the effects of weather factors such as temperature, solar radiation, humidity, and wind, combining both evaporation from t...

by Dean Malvick, Extension Plant Pathologist Hail damage has recently occurred to corn in parts of Minnesota. Some producers and crop consultants are asking about the potential value of applying foliar fungicides to corn damaged by hail. This article will cover key points on this topic. Why might applying fungicides to hail-damaged corn be beneficial? A common misconception is that hail damage opens the corn plants to infection and disease that can be controlled with fungicide applications. Few corn diseases in Minnesota are increased by hail damage except for common smut, Goss’s leaf blight and wilt, and possibly stalk rots. However, none of these diseases have been managed effectively with foliar fungicides. In addition, a study in Iowa found that foliar disease was lower in corn plots with simulated hail damage. What does the available data show about the potential value of fungicides applied to corn damaged by hail? The published results from field studies indicate no significant b...

It isn't hard to find Fusarium Head Blight (FHB) or Bacterial Leaf Streak (BLS) across much of Minnesota.  BLS is appearing relatively late in the grainfill period, and yield losses caused by the disease will be relatively small.   The same cannot be said for FHB, as the conditions continue to favor disease development. The best time to assess how many early infections occurred is probably this week.  These early infections result in the characteristic tumbstone kernels. These tombstone kernels can be easily removed during combining, and it is the simplest and cheapest way to reduce the amount of deoxynivalenol  (DON) in the harvested grain. Unfortunately, it's too early yet to see if the current stretch of favorable conditions will result in many late-season infections. Late-season infections are more difficult to deal with as the infected kernels have a near-normal appearance and weight but contain enough deoxynivalenol  (DON) to result in discounts or re...

The optimum time for pre-harvest management in small grains is right at or just after the crop reaches physiological maturity (PM). This applies regardless of whether you swath the grain or apply glyphosate as a pre-harvest treatment. At PM, the crop has the maximum kernel dry weight. No additional dry matter will be deposited into the grain. The kernel moisture percentage at physiological maturity is relatively high, and can vary from 20 to 40 percent. Research has shown that swathing just before PM doesn’t harm grain yield or quality. However, this practice isn’t recommended when using glyphosate as a pre-harvest tool. There are two visual indicators you can use to determine whether the crop has reached PM: 1) Loss of green from the kernel - The first indicator is the loss of green in the kernel, and the appearance of a dark layer of cells or pigment along the crease (Figure 1). Kernels in the same spike will reach physiological maturity at different times, with the middle of the hea...

Northwest Minnesota saw two unusually cool mornings last week, with minimum temperatures dipping well below 50°F  on Wednesday and Thursday morning (Figure 1). This is a cause of concern for the earliest-seeded spring wheat. Warmer temperatures during grain fill will result in higher Hagberg Falling Number (HFN) values.  Conversely, cooler temperatures will yield, on average, lower HFN. A short period of very low nighttime temperatures (< 50°F) very late in the grain fill period, however, is enough to yield a disproportionate increase of α-amylase in the seed. This phenomenon is referred to as late-maturity α-amylase (LMA).  Figure 1 - Daily minimum temperature recorded by NDAWN weather stations across eastern North Dakota and northwestern Minnesota on June 16th, 2025. LMA is a recessively inherited trait. In standard height wheat varieties, the expression of the trait is constitutive, allowing breeders to effectively select against the trait. In semidwarf wheat variet...

By: Eduardo Garay Lagos, On-Farm Research Manager and Outreach Specialist The University of Minnesota Manure Team is excited to host two Commercial Animal Waste Technician (CAWT) recertification training course options: in-person on August 7th, 2025, and online through October 31st, 2025.  With a growing focus on environmental sustainability and safe manure management practices, this course is crucial for staying informed on both regulatory updates and safety protocols.  The Minnesota Department of Agriculture (MDA) emphasizes that all training must be completed by November 1st to get CAWT recertification for licensure through the Minnesota Department of Agriculture (MDA). Anyone who fails to complete the course, whether in person or online by the October deadline, will need to retake the certification exam to renew their licensure.  In-person CAWT recertification: August 7th, 2025 only The final in-person Commercial Animal Waste Technicians (CAWT) recertification course ...

Dr. Fei Yang, University of Minnesota, Extension Corn Entomologist, and Dr. Yucheng Wang, University of Minnesota, Research Associate Northern corn rootworm will leave corn to  forage on other plants. Photo: Bruce Potter Corn farmers in Minnesota continue to face significant challenges from the corn rootworm (CRW) complex, primarily the Northern Corn Rootworm (NCR) and Western Corn Rootworm (WCR). Crop rotation has traditionally been a reliable method for managing CRW, as adults predominantly lay eggs in corn fields and the larvae survive only on corn roots. Rotating corn to other crops will disrupt the CRW life cycle and eliminate local populations. While significant Minnesota WCR populations have been limited to continuous corn, a subset of NCR has adapted to crop rotation through an extended diapause trait, which allows eggs to remain dormant in the soil for two or more winters. This adaptation enables larval survival in rotated fields when corn is planted every other year....

On this episode of Advancing Nitrogen Smart , Brad and Dan take some of the mystery out of variable rate nitrogen. What are we trying to accomplish when we use a variable rate management practice? What kinds of field conditions might benefit from VRN, and which conditions should be avoided with VRN? How might the other 3 R's (Timing, Source & Placement) play a part in variable rate decision making? All that and more on today's show.  TRANSCRIPT Guests: Brad Carlson, Extension educator (Mankato) Dan Kaiser, Extension nutrient management specialist (St. Paul) Additional resources: Is variable rate nitrogen based on yield maps a good idea? Variable rate nitrogen: What farmers should know Making sense of Minnesota’s corn fertilizer guidelines: Frequently asked questions and answers Fertilizing corn in Minnesota Nitrogen Smart --- Click here to listen to all Advancing Nitrogen Smart podcast episodes. For the latest nutrient management information, subscribe to the Nutrient Man...

Ryan Miller, Extension crops educator, and Tony Cortilet, Minnesota Department of Agriculture Palmer amaranth found in Yellow Medicine County in 2016. Palmer amaranth was added to the Minnesota Noxious Weed List in 2015; plants that earn a place on the noxious weed list have the potential to be or are known to be detrimental to some aspect of the common good. The full details on Minnesota’s noxious weed law can be found here.   Plants making it on the noxious weed list are placed in one of five categories: prohibited-eradicate, prohibited-control, restricted noxious, specially regulated plants, or county noxious weeds. Palmer amaranth was placed in the prohibited-eradiate category. This category contains weeds not known to exist in Minnesota or weeds not widely distributed in the state, and weeds in this category must be eradicated. In 2016, there was a significant introduction of Palmer amaranth to Minnesota; this came with a conservation seed blend that had sourced some of t...

by Robert L. Koch and Arthur V. Ribeiro Soybean gall midge larvae were found infesting soybean plants in a field near Rosemount in southeast MN on July 15, 2025. This is the first detection of this insect in Dakota County, which continues the eastward expansion of the known range of this pest . The infested plants were mainly located on an edge of the field adjacent to a corn field. The level of infestation on the edge of the soybean field was relatively low, with only 3.2% of soybean plants infested with soybean gall midge larvae. The infested plants showed the typical darkened lesions at the base of the stems near the soil surface, but none of the plants were wilting or dying. We will continue to monitor this field and others in the area.   As summer progresses (through August), it typically gets easier to detect soybean gall midge infestations because more plants become infested and infested plants become more symptomatic (wilting, dying and lodging, in addition to the darkened...

Today on the Nutrient Management Podcast  we discuss nutrient management for irrigated crops in Minnesota. How many irrigated acres are there in Minnesota? What are some of the benefits and risks of irrigation? In what ways can risks be mitigated - through timing, cover crop adoption and / or other general soil health practices? What should growers know about the latest irrigation research in Minnesota? If a farmer is considering adopting irrigation practices, what should they focus on first? This and much, much more on today's episode. TRANSCRIPT Guests: Daniel Kaiser, Extension nutrient management specialist (St. Paul) Carl Rosen, Extension irrigation specialist, Dept. of Soil, Water, and Climate (St. Paul) Vasu Sharma, Extension irrigation specialist, Dept. of Soil, Water, and Climate (St. Paul) Additional Resources: Irrigation Research shows precision irrigation technology can improve irrigation water productivity in corn Could adding irrigation to Minnesota corn fields ...

By: Anna Cates, Extension soil health specialist and Seth Naeve, Extension soybean agronomist A field day on September 9th will highlight some unique long-term drainage plots managed by the University of Minnesota since 2012. On rented farmland near Wells, MN, the plots have been used to investigate how varying tillage, fertility, and other soybean management practices perform on fields with and without drainage.  Researchers from UMN Extension are partnering with local Soil and Water Conservation Districts from Waseca, Faribault, and Blue Earth counties to present a field day for farmers to showcase these results and highlight the carbon intensity (CI) scores of various corn and soybean management practices.  Participants will have a chance to walk through the plots and see how the 2025 growing season is shaping up, as well as do soil health assessments in tilled and untilled plots. “Every year has been different,” says Seth Naeve, Extension Soybean Agronomist and Professor i...

Angie Peltier, UMN Extension crops educator, Northwest Research & Outreach Center, Jeff Coulter, UMN Extension corn agronomist and Anna Cates, UMN Extension soil health specialist 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 IPM educator Anthony Hanson. Minnesota’s corn progress and condition Minnesota’s corn in early July is progressing similarly to the 5-year average for crop progress and just slightly ahead of 2024, with the most recent USDA crop progress and condition report indicating that 6% of the crop is silking. Much of the corn in Minnesota is about 10 to 12 days away from silking and has entered the critical period of growth and development, which ranges from about 12 days before silking to 3 weeks after silking. Heat or drought stress before silking can cause a delay in silk emergence relative to pollen...