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Showing posts from August, 2018

Soybean/orange gall midge: A new insect associated with MN soybeans

by Bruce Potter, Extension IPM Specialist and Bob Koch, Extension Entomologist

A new potential pest, the soybean (or orange) gall midge, is causing injury to soybean in parts of the Midwest. Reports of this insect from Minnesota soybean are summarized here. Please inform us if you are aware of any additional infestations in Minnesota soybean fields.

Earlier this month, we received samples from a Rock County soybean field where stems were infested with small, pale to bright orange gall midge (Diptera:Cecidomyiidae) larvae (Figure 1).

Nutrient Management Podcast: Late Season Nutrient Management

The end of the growing season has presented a lot of variation in weather from wet to dry across Minnesota. Now is also the time to make decisions on fall fertilizer. On this episode, Dan Kaiser, Fabian Fernandez and Jeff Vetsch discuss where growers' minds should be at this point.

We cover:

What to be concerned about, nutrient-wiseWhat can be done at this point with deficiency symptomsQuestions we're hearing across MinnesotaHow to think through decisions on fall nitrogen, sulfur, phosphorus and potassium
IPM Podcast: Late summer corn and soybean disease update for Minnesota. http://blog-crop-news.extension.umn.edu/2018/08/ipm-podcast-late-summer-corn-and.html

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Support for this project was provided in part by the Agricultural Fer…

Predicting the last irrigation for corn and soybeans in central Minnesota*

Updated by: Vasudha Sharma, Assistant Extension Professor-Irrigation Specialist
*Article was first published in July 1988 by Jerry Wright and Extension Agronomists, Leland Hardman & Michael Schmitt.
*Article was revised in 2006 by Jerry Wright, Retired Extension Engineer, Dale Hicks, Retired Extension Agronomist, Seth Naeve, Extension Soybean Agronomist
Determining the amount and timing of the last few irrigations of the season is one of the most critical water management decisions. Discontinuing too early in the season to save water or reduce pumping cost could mean a much greater reduction in yield returns than the cost of pumping. On the other hand, irrigating right up to crop maturity may mean using 1 to 3 inches more irrigation water than necessary and increasing operating costs $3 to $15 per acre depending on power source. The purpose of this article is to present some guidelines for predicting the last irrigation for corn and soybeans when irrigation water supplies are ade…

Late Season Nitrogen Deficiency Symptoms Across Minnesota

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.

We had a lot of moisture early in the season that may have prevented deep rooting, and potentially led to N loss through denitrification. In addition, some growers were prevented from getting into the field to apply N splits. One final factor is that plants now have a big sink – the cob – causing N to mobilize within the plant. These factors, coupled with a recent spell of fairly dry and hot conditions have led to the current conditions.

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 corn does not need a lot of N. As the season progresses, plants need more N as they accumulate dry matter in the …

Late Season Nutrient Management

Dan Kaiser, Jeff Vetsch and Fabian Fernandez talk through how weather and management factors may be affecting late season nutrient deficiency symptoms. We talk through how to manage deficiencies at this point in the season, the status of fields across the state, and what to consider before making fall application decisions.

IPM Podcast: Late summer corn and soybean disease update for Minnesota. http://blog-crop-news.extension.umn.edu/2018/08/ipm-podcast-late-summer-corn-and.html

Ag Professional and Grower Insect and Disease Field Day at the Rosemount Research and Outreach Center

by Dave Nicolai, Extension Crops Educator
The University of Minnesota Extension and IPM program are sponsoring an Ag Professional and Grower Insect and Disease Field Day. The Field Day will be held on Wednesday, September 5 from 9:00 am to 1:00 pm at the Rosemount Research and Outreach Center located at 16975 Arkansas Avenue in Rosemount. Agricultural professionals and growers are invited to the field day for a tour of applied insect and disease research conducted by University of Minnesota Extension faculty. Topics will include soybean aphid research, corn and soybean diseases and corn rootworm research and management.

IPM Podcast: Late summer corn and soybean disease update for Minnesota

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. Dean Malvick, University of Minnesota Professor in Plant Pathology. Dr. Malvick is the University of Minnesota Extension Specialist for corn and soybean diseases. Dr. Malvick provides an overview of the important corn and soybean diseases effecting Minnesota crops during 2018 including soybean white mold and sudden death syndrome along with corn leaf diseases, Goss’s wilt and bacterial leaf streak. In addition the identification and management of these diseases by growers is also detailed for listeners.

8 Things to Keep in Mind When Planning for Fall Manure Applications

With a potentially tight window for getting on fall manure in the coming months, the best policy is to be prepared. Now’s the right time to start thinking about fall applications. Here are eight key things to keep in mind as you plan.  Start prepping equipment to make sure everything’s looking good for fall application.Plan ahead for which crops will receive manure applications. Remember MPCA regulations for maximum application rates. Wait until soil temperatures are below 50 degrees Fahrenheit. At these cooler temperatures nitrogen is more likely to stay in the organic or ammonium forms. In warmer soil temperatures, nitrogen converts to nitrate, a form that can be lost more quickly.If you want to apply 1-2 weeks earlier, studies have shown some indications that applying with a nitrification inhibitor may potentially help, but don’t expect that to last if you apply in September.If you’re going to apply in late summer or early fall following sweet corn and canning crops, get a cover cr…

Assistance requested with plant and soil sample collection to study Soybean SDS pathogen distribution

Dean Malvick, Extension plant pathologist
We are working to understand the distribution of the fungal pathogen that causes soybean sudden death syndrome (SDS) and root rot of edible bean and alfalfa in Minnesota. Your help is requested.

The soilborne pathogen (Fusarium virguliforme) that causes SDS of soybean and root rot of edible bean and other legumes is spreading in Minnesota. Our study has the goal of monitoring and mapping the presence of this pathogen in soybean, dry edible bean, and alfalfa production fields across Minnesota. We request help with sample collection from your area.

Kura clover living mulch provides opportunity for high corn yield with reduced nitrogen input

Jonathan Alexander1, Jeff Coulter1, John Baker1,2, and Rodney Venterea1,2
1University of Minnesota, 2USDA-Agricultural Research Service
A living mulch is a cover crop under-seeded into annual crop production. Kura clover is a vegetatively-spreading, nitrogen (N)-fixing, winter-hardy perennial legume native to eastern Europe. Kura clover’s spreading habit gives it the ability to survive harsh agronomic management, which makes it a prime candidate for use as a perennial living mulch.

Kura clover’s N-fixing ability and dense mat of roots benefit the producer and the environment by reducing N application requirements, protecting against soil erosion, and capturing excess N in the soil.

Managing late-season soybean aphid infestations: It isn't getting easier.

by Robert Koch (Extension Entomologist)

Aphid populations continue to increase, especially in southern Minnesota where we are seeing more fields surpassing threshold levels and requiring treatment to protect soybean yield. Late-season management of soybean aphids can be challenging. In this article, I provide some considerations for scouting and making management decisions for soybean aphid in the later part of the growing season. How much longer do you need to keep scouting? What densities of aphids should (or should not) be treated with insecticide?  What about later growth stages? What if there are spider mites in the field too?  Can you stop scouting if you already applied an insecticide to a field?  However, before diving into this discussion, be sure you can accurately determine the growth stage of your soybean field (review Soybean growth stages for a refresher).

Hay auction summary

by Randy Pepin, UMN Extension Educator, Stearns, Benton, and Morrison Counties
pepin019@umn.edu or (320) 333-1369
Keeping up with current hay prices is important for most livestock farmers. We calculate price averages, quality averages, and the corresponding ranges of the various hay lots from recent hay auctions in Sauk Centre, MN. We also keep an updated history of recent years of some selected hay lots and create graphs of four different quality types of medium square alfalfa bales. This is posted every month, about a week after the last auction of the month.

Assistance with 2018 European corn borer and corn disease survey requested

Bruce Potter, Bill Hutchison, Ken Ostlie, 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, about 150 corn fields are surveyed for the presence of corn borer damages, overwintering corn borer larvae, and corn diseases. During the growing season weekly updates of ECB moth captures in black light traps are made available: 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.

4 Considerations for Fall Sulfur Application

As crazy as it sounds, fall is right around the corner. What’s your strategy for post-harvest fertilizer application?  We’ve been getting questions about sulfur application as farmers look for their best options. If you’re thinking about sulfur, here are four things to consider to ensure the most efficient use for next year’s crop.
1. Your crop
Corn, alfalfa, and canola have shown the greatest benefit to fertilization of sulfur in Minnesota. Applying ahead of, or in the case of alfalfa to an established stand, make the most sense economically. Small grains have shown a potential for response on soils with low organic matter (3.0% or less) while soybean responses have been inconsistent. 
2. Your soil type
Soils with greater potential for leaching are not good targets for fall sulfur application for sources that contain sulfate. Sulfate will move in the soil profile and soils with medium to coarse texture are not good targets for fall sulfur application. Fine textured poorly drained soil…

If you plan to use chlorpyrifos for control of soybean aphid or other pests, keep in mind BMPs for use and respirator requirements

by Robert Koch (Extension Entomologist, Univ. of MN), Trisha Leaf (Research Scientist, MN Dept. of Agric.), Natalie Hoidal (Pesticide Safety & Environmental Education, Univ. of MN)

The challenges posed by soybean aphid resistance to pyrethroid insecticides have resulted in more growers turning to insecticides containing chlorpyrifos for management of soybean aphid outbreaks. Chlorpyrifos is an organophosphate insecticide with broad-spectrum activity that is used for management of pests in various agricultural crops. Chlorpyrifos is an active ingredient in various products, including but not limited to Lorsban, Cobalt, Dursban, Nufos and Yuma. In this article, we urge growers and applicators to keep in mind best management practices (BMPs) for use of chlorpyrifos and provide a reminder about respirator requirements for this insecticide.

Japanese beetles feeding on soybean: What should you do?

by Robert Koch (Extension Entomologist)

In parts of southeastern Minnesota Japanese beetle has been actively feeding on soybean. These large beetles with shiny green- and copper-colored bodies, chew small holes in the leaves leaving a lace-like appearance ( see image 1). Japanese beetles will also feed leaves and flowers of many other plants, including silks of corn. Japanese beetle abundance and activity is most intense through July and August, but some individuals will remain active into fall. Here, I briefly review scouting and thresholds for management of Japanese beetle in soybean.

Soybean Field Day: Winning the Battle Against Yellow Beans – Fighting IDC and SCN

by Dave Nicolai, Extension Crops Educator
The University of Minnesota Extension is offering a workshop and field tour on Tuesday, August 14th highlighting soybean management strategies for battling Iron Deficiency Chlorosis (IDC) and Soybean Cyst Nematode (SCN). The tour will feature a UMN research site studying the interactions between IDC and SCN, along with trials evaluating commercial products from Bayer, Valent, Monsanto, and West Central Inc.