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Showing posts from September, 2019

Check your fields this fall for the presence of Palmer amaranth

Jeff Gunsolus, Extension agronomist - weed science

The fall harvest season is a good time to look for the presence of Palmer amaranth. Palmer amaranth is on Minnesota’s prohibited noxious weed and seed list with the goal to eradicate Palmer amaranth before it becomes widely established. Palmer amaranth is on Minnesota’s prohibited noxious weed and seed list with the goal to eradicate Palmer amaranth before it becomes widely established.

To date, the Minnesota Department of Agriculture (MDA) has been able to eradicate Palmer amaranth in the fields reported to them and will continue to monitor affected fields and track down sources of contamination. The key is proper identification and rapid reporting to the MDA via the Arrest the Pest line at 1-888-545-6684 or arrest.the.pest@state.mn.us
Identification is key Although Palmer amaranth can be confused with other amaranth (pigweed) species throughout the growing season, the fall is generally when Palmer amaranth literally stands out fr…

When insects take care of the pest control for us

Welcome to the 6th IPM Podcast for Field Crops
This Podcast is sponsored by the UMN Extension Integrated Pest Management (IPM) Program.

In this week’s podcast, we feature Dr. George Heimpel, University of Minnesota Professor of Entomology, and members from his lab, Dr. Carl Stenoien and Jonathan Dregni.

Heimpel discussed how biological control, or beneficial species suppressing other pests, fits within IPM through reducing the likelihood of pest populations reaching damaging levels. In cases of invasive species, insects that feed on the invasive pest in their native range may be imported in after heavy regulatory scrutiny and can turn a common invasive pest into only a sporadic pest.

Multiple species of parasitic wasps that have been considered for import against soybean aphid were discussed. These are small wasps that cannot sting people, but instead lay eggs inside the host insect. When the eggs hatch, the larvae consume the aphids. One species, Aphelinus certus, has been found para…

Webinar addresses Haney soil test

If you have wondered how to interpret the Haney test as an indicator of soil health, plan to tune in to this webinar:
Date: October 7, 2019Time: 11:00 a.m. - 12:00 p.m.What: Webinar How: Register onlineCost: No fee The Haney test tries to assess biological activity in your soil. The results include many different metrics representing microbial activity and food sources. Dr. Anna Cates, state soil health specialist, will guide you through how the various measurements are done and how to interpret your results. Liz Stahl, Extension Educator in Crops, will discuss U of MN research comparing results of the Haney Test to standard soil testing procedures, and the implications if you want to use the Haney test in determining fertilizer needs.

One (1) CCA CEU has been applied for:
0.5 Soil and water (SW)0.5 Nutrient management (NM)

Fall sulfur application: Selecting the best product

By: Dan Kaiser, Extension soil fertility specialist

Sulfur has become an important crop nutrient applied to corn fields across Minnesota.

Recent research has shown a benefit from applying sulfur in fields low in organic matter and in high residue situations where mineralization and release of sulfate sulfur from organic matter are limited.

What can make sulfur application challenging is that the form of sulfur available for crop uptake is sulfate. Sulfate is an anion and, like nitrate, can leach deep in the soil profile where crop roots cannot reach. The addition of sulfur fertilizers to fall phosphorus and potassium applications leads to questions about what the best form of sulfur is. Choosing the right form is critical to ensure crops are not short of this necessary nutrient early in the growing season.

Commercial sulfur fertilizer sources include either elemental or sulfate forms of sulfur. The difference between the two is that sulfate sulfur forms, such as gypsum or ammonium su…

Late season corn and soybean disease notes for Minnesota

Dean Malvick, Extension plant pathologist

Although it is getting late in this growing season, it is worthwhile to take note of corn and soybean diseases that have developed in fields in Minnesota and the region. Several different diseases have been increasing in corn and soybean, and we continue to watch development of tar spot of corn in nearby states.
Corn diseases Several different diseases have developed in corn fields in Minnesota this year. Physoderma leaf spot was a concern in southwestern Minnesota, especially in mid-summer. Bacterial leaf streak and Goss’s wilt also developed in multiple fields in southern and/or northwestern Minnesota, with bacterial leaf streak being most common again in fields with sweet corn. More recently, northern corn leaf blight, rust, and gray leaf spot have been easy to find at low levels to moderate in many fields across Minnesota.

Although most of these diseases developed too late to have significant effects on corn yields, their presence …

What should growers look for in soil health tests?

In this episode of the Nutrient Management Podcast, we discuss soil health tests. What is the consensus definition of soil health? What should growers look for in soil health tests, and how should they go about testing their fields? What research is available in Minnesota tying soil health tests to crop performance and yield?
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Support for the Nutrient Management Podcast is provided in part by the Agricultural Fertilizer Research & Education Council (AFREC).

Assistance with 2019 European corn borer and corn disease survey requested

Bruce Potter, Bill Hutchison and Dean Malvick

Entomologists and plant pathologists at the University of Minnesota continue to document and understand changes in European corn borer (ECB) populations and corn diseases in our state.

Each fall, approximately 150 corn fields are surveyed for the presence of corn borer damage, overwintering corn borer larvae, and corn diseases. During the growing season, weekly updates of ECB moth captures in black light traps are made available at: https://www.vegedge.umn.edu/moth-data/ecb-info. Funding from the Minnesota Corn Research and Promotion Council has provided us an opportunity to improve these efforts.
Monitoring still important Since the widespread adoption of Bt traits in the 1990s, populations of ECB been quite low; the areawide suppression of ECB has been correlated with Bt use rates. Over the past few years, corn growers have increased the number of acres planted to hybrids without Bt traits (conventional corn) for ECB. Additionally, Bt …

It is time for a ne-crop-sy

The proof is in the pudding and that is never truer than when harvesting. What looked like a really good HRSW crop is turning into some real disappointment from some.  Apart from problems with sprout damage and low Hagberg Falling Numbers (HFN), yields have been much lower than anticipated or hoped for.  The causes of these low yields vary. It is, however, important to not scapegoat. Especially if the goat, or Wheat Stem Sawfly,  didn't cause the yield losses.

While the nuisance of Wheat Stem Sawfly (WSS) spread farther across the heart of the Red River Valley, it is not likely the culprit of the low yields that have been reported.  There is little evidence in the literature that the feeding of WSS is a major yield robber. The inability to pick the crop up is by far the greatest cause of yield losses.  In this area, harvest losses due to WSS are minimal as evidenced by the close shave I see in many fields.

The fungal leaf diseases than most commonly rob yield were either very well…

Field to stream to gulf - Part Two

In Part Two of this special episode of the Nutrient Management Podcast, we shift the focus to the larger Root River watershed, examining how a buildup of older sediment sources can muddy the waters, both literally and figuratively, for water quality. Topics include the unexpected benefits of nuclear testing, regions trapped in their own history, when to focus on practices versus results, and making water walk instead of run. Thank you to the Minnesota Agricultural Fertilizer Research and Education Council (AFREC) for their support of this podcast.

Field to stream to gulf - Part One

In Part One of this special episode of the Nutrient Management Podcast, we discuss what happens when soil and nutrients leave a field. Extension educator Greg Klinger is joined by Kevin Kuehner from the Minnesota Department of Agriculture and the Root River Field to Stream Partnership in southeast Minnesota. How much of the soil and nutrients that leave farm fields in the region actually end up in the streams and rivers of the region? Greg and Kevin explore how dissolved nutrients and soil-attached nutrients move at different speeds through watersheds, road ditches as sediment control structures, the value of digging holes in the Driftless region, and how we often underestimate the value of existing conservation practices. Thank you to the Minnesota Agricultural Fertilizer Research and Education Council (AFREC) for their support of this podcast.

New manure application rate guidelines for Minnesota

By: Melissa Wilson, Extension manure management specialist

Manure application rate guidelines in Minnesota have recently been revisited and updated as needed to reflect recent research findings for nitrogen and phosphorus needs of crops.

Check out the updates here: z.umn.edu/ManureRates
What’s new?Nitrogen: The corn nitrogen guidelines recommended by the University of Minnesota were recently updated for non-irrigated soils. These guidelines use the Maximum Return to Nitrogen (MRTN) approach, which relies on calculating the price ratio for the cost per pound of nitrogen divided by the value of corn per bushel. For manure, we suggest using the 0.05 price ratio MRTN as the maximum rate of manure nitrogen that should be applied. This is relevant to those that have manure readily available at a low (or no) cost. For those that pay a premium, the 0.1 price ratio MRTN, or higher, may be more relevant and will result in a lower application rate. Lower application rates may also be considere…

Gopher Coffee Shop podcast: Nutrient management

In this installment of the Gopher Coffee Shop podcast, Extension educators Ryan Miller and Brad Carlson sit down with Dan Kaiser, Extension nutrient management specialist with the Department of Soil Water and Climate, to learn about Dan and his role with Extension. We discuss nutrient management and best management practices (BMP’s) in Minnesota agriculture. What are BMP’s and how are they adjusted over time to adapt to changes in climate and agricultural production? We talk about these recent changes in agriculture and climate and BMP adaptations. About half way through the podcast we talk about newer technologies, the current economic conditions, and how farmers might adjust crop and nutrient management to “keep-it-simple” and maintain profitability. Enjoy!

Nutrient Management Website: https://extension.umn.edu/crop-production#nutrient-management.
Listen to the podcast The Gopher Coffee Shop Podcast is available on Stitcher and iTunes.

For a chance to read about various crop ma…

Late-season nitrogen deficiency in corn: What you need to know

By: Brad Carlson, Extension educator

If you’ve seen nitrogen (N) deficiency symptoms in corn popping up in fields across Minnesota, you’re not alone. Crops in the past couple weeks have begun to show substantial N deficiency symptoms around the R3-R4 stages.

Challenging conditions during planting season led to less than ideal seedbeds, with compacted areas in many fields affecting crop rooting. Additionally, a widespread issue this year is compaction caused by manure applications when fields were too wet. In some locations, there was a lot of moisture early in the season that may have prevented deep rooting, and potentially led to N loss through denitrification. One final factor is that plants now have a big sink – the cob – causing N to mobilize within the plant.

Between fertilizer and mineralization, the corn plant will have enough N to stay green under normal conditions. This makes it hard to detect deficiency either visually or with sensors, especially early in the season when co…