Cropping Issues in Northwest Minnesota

This article was originally posted on the Minnesota Crop News blog by University of Minnesota Extension 's Liz Stahl an educator in crops and Bruce Potter an integrated pest management specialist. A significant amount of seed planted this year will have been treated with one or more fungicide, insecticide, nematicide, or biological seed treatments. The following are some key precautions and reminders to follow when working with treated seed to help prevent pesticide exposure to handlers, non-target organisms, and the environment. Treated seed should be cleaned up or covered with soil to prevent exposure to birds and other wildlife. Photo: Liz Stahl

A black cutworm pheromone trap will be deployed at the Northwest Research and Outreach Center in Crookston, the northernmost location in the UMN Black Cutworm Trapping Network. The article below was originally posted in the MN Crop News Blog by Bruce Potter, University of Minnesota Extension Integrated pest management specialist. Figure 1. Black cutworms and damage to soybean. The black cutworm can be a significant pest of corn, sugarbeets and other crops. Because they cannot survive our Minnesota winters, the risk of economic crop loss depends on how many moths arrive and when they arrive with respect to crop development.

Figure. Spring UAN application. The article below about corn was originally posted as a MN Crop News article by Jared Spackman, University of Minnesota (UMN) graduate student, and Fabian Fernandez, UMN Extension Specialist. Wet conditions last fall and this spring have limited the number of acres that received nitrogen in preparation for the upcoming growing season. This creates the challenging dilemma of whether to delay planting in order to get fertilizer down. Most Minnesota soils can supply sufficient nitrogen to meet early corn growth without a yield reduction. The best bet is to plant corn on time to optimize yield potential and come back later to apply nitrogen.

This article was originally posted on the MN Crop News Blog by Jared Goplen, University of Minnesota Extension Educator in crops. Can you identify these weeds? It really can be that simple. Last summer I was introduced to an app / website called iNaturalist, a tool commonly used by those working in natural resources. While it can be used to help identify nearly any species, it works especially well to identify weeds. Best of all it is free!

Figure. Spring regrowth of a cereal rye and rapeseed cover crop mixture. The article below was originally posted in the MN Crop News Blog by Gregory Klinger, University of Minnesota Extension educator in ag water quality protection. I was recently asked how growing cover crops can impact the nitrogen credit we give to corn grown after soybeans. This credit, which is often incorrectly assumed to be based on soybean adding nitrogen to the soil, is mostly related to the carbon-to-nitrogen ratio of soybean residue. The main issue to consider is: what is happening to soil nitrogen as that cover crop is decomposing? A lot of this comes down to what the cover crop is, how much biomass is out there, and what stage of growth it is at.

Soil crusting.  The longer the delay between planting and seedling emergence, particularly in soils with poor structure, the greater the chance that weather can interfere with emergence.  An unexpected rain event followed by warm temperatures that quickly dry soils can cause soil to form a crust.  Crusted soil creates a barrier that is more difficult for emerging seedlings to penetrate.  For soybean this can result in plant death if emerging stems break below the emerging cotyledons (seed leaves, Figure).  Crusting can also lead to uneven emergence. Figure. Blue arrows are pointing to soybean cotyledons or 'seed leaves'. If emerging seedlings break off below the cotyledons the plant is unable to recover.

Field soils are anything but sterile environments and there are many organisms that have the potential to help or harm our crops and the many microbial and chemical processes on which they rely.  Oomycetes are a group of plant pathogens that have some fungus-like and some algae-like characteristics. Oomycetes produce swimming spores called zoospores and oomycete growth and the production and release of zoospores is favored by free water and either warm or cool soil conditions.  Disease caused by the Pythium species of oomycete pathogens are favored by cool wet soil conditions (Figure).  Symptoms caused by Pythium infection can include rotted seeds or roots and pre- or post-emergence damping off. Figure. Preemergence damping-off, characteristic of Pythium daming-off and root rot ( Pythium spp.). Image: Courtesy M. V. Avanzato; Reproduced, by permission, from Hartman, G. L., et al., eds. 2015. Compendium of Soybean Diseases and Pests. 5th ed. American Phytopathological Society, S

While we continue to have no control over the weather, we have access to near- and longer-term temperature and precipitation ‘normals’ and forecasts that our forebears did not.  Knowledge about what has happened in the near past, freeze probabilities, current and forecasted air temperature and precipitation and the earliest and latest crop insurance planting dates can help crop producers to better gauge the risk of either planting on a particular day or holding off.  Oftentimes decisions hinge on field conditions, just how many acres need to be planted and an individual farmer’s risk tolerance. What does the data tell us about final frost dates? The National Oceanic and Atmospheric Administration (NOAA) uses the 1981 through 2010 calendar years to calculate the probability of a later 28 degree freeze than a given date at a given location.  Their summary for the Northwest Research and Outreach Center in Crookston lists that there is a 90 percent probability of a 28 degree frost

Sampling program results.  Samples submitted through the Minnesota SCN sampling and education program originated from 28 Minnesota counties, with the majority of the 363 samples coming from the most newly infested northwest region (Figure). While 49.6% of samples had SCN population densities below the limit of detection of 50 eggs per 100 cubic cm of soil, the remaining 50.4% tested positive. One sample submitted through this survey included the first documented infestation in Beltrami County. Among samples testing positive:

Questions: are you or do you know a college student majoring in agronomy, entomology, plant pathology or agricultural communications? Do you or do they have a job or paid internship for summer lined up? Are you or are they enrolled in college for the Fall 2019 semester? If your answers are yes, no and yes respectively, consider either applying for or passing along the information about this exciting integrated pest management (IPM) internship at the University of Minnesota Extension office in Crookston. Soybean aphid. Photo: Christina DiFonzo, Michigan State University, Bugwood.org. Licensed under a Creative Commons Attribution 3.0.

This article detailing the Palmer Amaranth Summit was written by Communications specialist Dana D'Amico was originally posted on the Minnesota Invasive Terrestrial Plants & Pests Center website .  Palmer amaranth-infested Illinois soybean field. Photo credit: Robert Bellm. Tracking Palmer amaranth in Minnesota Palmer amaranth in Minnesota started with just one pathway of spread – a single company selling contaminated native seed mix for conservation plantings. Nearly two years later, Palmer continues to spread by other means, including via humans, equipment, livestock, hay, forage and feed. In 2018, Palmer was reported at 44 sites across 6 counties. This includes the first sightings of Palmer in soybean fields. MDA's Noxious Weed and Hemp Unit Supervisor Tony Cortilet discusses Minnesota's response to date. How can you help slow the spread?