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Showing posts from August, 2020

When it rains, it pours: How heavy rainfall can lead to nutrient loss

By: Lindsay Pease, Extension nutrient management specialist From May to July of this year, 13 inches of rain fell at the Northwest Research & Outreach Center in Crookston — about 3.5 inches greater than the 30-year average. What started out as a near-normal season for rain took a sudden turn with seven inches of rain in July. Quite literally, when it rained, it poured. Many factors play into whether heavy rains lead to nutrient loss. Some of these factors are how much it rained, what soil type you have, what crop you grew, how much fertilizer you applied, how quickly it rained after you applied the fertilizer, and whether you have tile (or irrigation). One of the key factors that determines if water will become soil moisture or runoff is rainfall intensity. The soil can only absorb water so fast. This is the soil’s infiltration rate. If rainfall intensity exceeds the soil’s infiltration rate, you get ponding or runoff. Infiltration rate depends on both the soil’s physical propertie

Are My Numbers Falling....Again?

Reports of low Hagberg Falling Numbers (HFN) in this year's HRSW crop are coming in from the Crookston to Mahnomen area.  This is the same area were growers noticed problems first last year.  I wrote a blog post last year that details a lot of the technical details of the HFN test and why it matters to buyers.  You can find that post  here . We also learned some things from last season.  First, the number of rain events i.e. repeated wetting and drying cycles matters to trigger preharvest sprouting.  No discernable differences in HFN were found between varieties with a Preharvest Sprouting (PHS) tolerance rating of 1 and 2 and varieties with PHS tolerance of 3 or worse when less than 4 rain events were recorded between physiological maturity and grain harvest.  It took actually 12 wetting events to start seeing the first sprout damage and a corresponding drop in HFN in the varieties with poorer PHS tolerance. Secondly, we had no indications that Late Maturity Alpha-amylase (LMA) pl

Field Crops IPM Podcast: Soybean gall midge, spider mites, and corn rootworm in southern Minnesota

  Welcome to the 3rd IPM Podcast for Field Crops of 2020. Subscribe to the podcast and never miss an episode on iTunes , Google Podcasts, and Spotify. This Podcast is sponsored by the UMN Extension Integrated Pest Management (IPM) Program. In this week’s podcast, we feature Bruce Potter , University of Minnesota Extension IPM Specialist based out of the Southwest Research and Outreach Center in Lamberton, MN. Potter discussed insect pests he has been seeing in southern Minnesota and across the state ranging from soybean gall midge, two-spotted spider mite, and corn rootworm. Soybean gall midge continues to be a concern as a new emerging pest of soybean in southwestern counties. Larval feeding under the epidermis of plants can cause heavy yield loss through wilting and plant death, especially on field edges. Research is underway to understand this new pest's biology, but management is complicated by multiple generations throughout summer and related difficulty timing foliar ins

Is boron deficiency a problem for crops in Minnesota?

Signs of boron toxicity in soybeans. Boron toxicity can also be an issue, so be cautious if you're considering applying boron fertilizer. (Image credit: Dan Kaiser/University of Minnesota Extension) By: Dan Kaiser, Extension soil fertility specialist Boron (B) is a micronutrient needed in small quantities by crops. Since the need for the nutrient is low, there have not been recommendations for boron fertilizer application in most crops across Minnesota. Based on tissue sampling results, some say boron fertilizer is needed to maximize yields for some crops. However, the data indicating what a good versus a bad plant tissue concentration is across most of the Corn Belt is lacking as boron deficiencies are not widespread. Without a deficiency, it is very difficult to generate sufficiency levels in plant tissue samples. Alfalfa Boron deficiency for alfalfa has previously been identified in Minnesota. Alfalfa is much more sensitive to boron deficiencies than other crops. However, it is

Updated video: Late season scouting for soybean gall midge

Bruce Potter, IPM specialist With a large number of adults emerging at research sites in southwestern Minnesota this past week, now is a good time to find the soybean gall midge larvae. A short video has been updated to include late season scouting. Growers are encouraged to keep an eye out when scouting soybeans, since damage and symptoms are increasing in infested fields.

Improving profitability by interseeding wide-row corn with cover crops

By M. Samantha Wells, Extension agronomist – Forage/Cropping systems High-quality cover crops in a bed of harvested corn stalks, Goodhue, MN. Photo: Alan Kraus, CRWP. Cover crop adoption across the U.S. is on the rise, but Minnesota adoption has hovered around 2%. While Midwestern farmers understand the importance of soil health, adopting sustainable technologies that offer limited near-term economic returns is challenging. Four southeastern Minnesota farmers, the Cannon River Watershed Partnership (CRWP) and the University of Minnesota are addressing that challenge. They are pairing wide-spaced corn rows with cover crops to test whether both economic and ecological outcomes could be improved. Why wider rows? Row spacings vary between operations, crops, and locations across the U.S., but generally, corn is typically managed in 30-inch rows. For 40 years or more, crop rows have narrowed to maximize sunlight interception and subsequent profitability. As a result, thirty-inch

Tar Spot of Corn Found in Minnesota in 2020

By Dean Malvick, Extension plant pathologist Tar spot of corn was found last fall for the first time in Minnesota. In 2020, tar spot is again developing in corn fields in southern Minnesota. Tar spot was recently confirmed at low levels in two fields in southern Fillmore County. This disease was also found near those sites in 2019. Now is a good time to scout for tar spot in fields in Minnesota to determine how far this disease has spread. The dry weather in many areas of Minnesota in late July and early August likely suppressed tar spot, but recent rains may have favored development of this disease. Although tar spot was found only in southeastern Minnesota in 2019, we do not know how far this disease spread and it may not be restricted to southeastern parts of the state. Identifying tar spot Tar spot of corn. Photo: Dean Malvick Corn tar spot is caused by the fungus  Phyllachora maydis . The tar spot fungus infects leaves (and sometimes husks) and produces raised, sma

Reminder - U of MN Virtual Cover Crop Field Day: Setting up for Success, August 18

By Liz Stahl, Extension Educator - Crops If you are interested in learning about some of the latest U of MN research on cover crops, plan to attend the U of MN virtual Cover Crop Field Day: Setting Up for Success, August 18 at 1:00 p.m. Through this live webinar, researchers and educators will highlight U of MN research that provides management tips and considerations to help farmers and ag professionals successfully incorporate cover crops into Minnesota cropping systems. The program will run from 1:00 to 2:30 p.m., with presentations from 1:00 to 2:00 followed by a cover crop roundtable from 2:00 to 2:30. Although there will be time for questions and answers after each presentation, the roundtable will provide an opportunity for additional open discussion with attendees. Registration is free, thanks to support from the Minnesota Sustainable Agriculture Research and Education (MN SARE) program. Topics & speakers include: Cover crops as a tool in waterhemp management? – Gregg

Field Crops IPM Podcast: Soybean and corn diseases in late summer and what to plan for next year

Welcome to the 2nd IPM Podcast for Field Crops of 2020. Subscribe to the podcast and never miss an episode on iTunes , Google Podcasts, and Spotify. This Podcast is sponsored by the UMN Extension Integrated Pest Management (IPM) Program. In this week’s podcast, we feature Dr. Dean Malvick , University of Minnesota Professor of Plant Pathology. Dr. Malvick discussed what diseases he is keeping an eye out for in Minnesota soybean and corn: Soybean diseases White mold symptoms are beginning to occur, though the next few weeks will tell how severe it is region-wide. Dr. Malvick explained how we are past the window where treatments would be effective for white mold, but growers should consider varieties for next year that have partial white mold resistance, though no variety is entirely immune. Sudden death syndrome (SDS) of soybean is caused by a fungus that infects roots early in the season, and symptoms are generally not visible until later in the season. It has been confirmed in