Monday, December 5, 2016

Aphid-resistant soybean varieties available for Minnesota

by Siddhi Bhusal (Postdoctoral Associate), Anthony Hanson (PhD Student), Aaron Lorenz (Assistant Professor) and Robert Koch (Assistant Professor)

Soybean aphid is a significant pest of soybean in Minnesota. Soybean breeders have developed various soybean varieties that carry aphid-resistance traits, in addition to other promising agronomic characteristics. Aphid-resistant varieties can provide an effective, economical, and more environmentally sustainable means of protecting soybean from soybean aphid. 

A list of commercially available aphid-resistant soybean varieties suitable for Minnesota can be found in:

Commercially-available aphid-resistant varieties carry a single aphid-resistance gene (i.e., Rag1 or Rag2) or a combination (i.e., pyramid) of the two resistance genes. Pyramiding of two or more aphid-resistance genes in single soybean varieties is underway in several soybean breeding programs in the region. The U of MN Soybean Breeding Program, in collaboration with U of MN Department of Entomology, is working on pyramiding various combinations of Rag1, Rag2, Rag3/rag3, and rag4 genes of aphid resistance in soybean varieties adapted to Minnesota conditions and with superior traits for other agronomic factors. Varieties with multiple aphid-resistance genes will provide more robust and durable resistance against multiple biotypes of soybean aphid. 

Thursday, November 17, 2016

NDSU and U of M Extension to hold Conservation Tillage Conference in December

by Jodi DeJong-Hughes, Extension Educator

University of Minnesota along with North Dakota State University Extension Service, is hosting the 2016 Conservation Tillage Conference on Dec. 13-14 in Fargo, ND.

Family members from the Jorgensen Land & Cattle will be the keynote speakers. This fourth generation, 20,000 acre farm includes a diverse cattle, crop and hunting operation in south central South Dakota. They will discuss how and why soil health, livestock integration and sustainability are the driving forces in their operation.

The schedule includes an extensive variety of speakers, drawing on experienced growers, agronomists and academic experts. Whether a novice crop consultant or experienced in conservation tillage, participants will learn about nearly every aspect of improving soil health and productivity.

Topics include residue management, effective use of strip and vertical till, cover crops, extended grazing, soil biology, weed management and fertility in reduced-till systems.

Informal table-talk sessions will allow for time to interact with speakers and industry representatives. More than 25 vendors representing equipment, and providing educational information will be on-site throughout both days.

A farmer panel will conclude day one. Farmers using multiple tillage systems and cover crops will talk about their experiences and “tricks” they’ve learned through the years. The second day will start with hands-on demonstrations to show soil health parameters and weed management.

Attendees who stay for the entire conference will be offered seven Certified Crop Adviser continuing education units (CEUs).

Early bird registration is $125 for the full conference. Registration will increase to $155 after Nov 30. Registration and more information on the agenda, lodging and program speakers are available online at

Thursday, October 13, 2016

Pictorial guide aids in Palmer amaranth and tall waterhemp identification

by Phyllis Bongard and Jeff Gunsolus

With the recent confirmation of Palmer amaranth in Minnesota, it is critical to identify this noxious weed, so it can be eradicated before it becomes widespread. A new pictorial guide compares key characteristics of Palmer amaranth and tall waterhemp at several growth stages throughout the growing season to aid in this identification.

The new guide, “Comparing Palmer Amaranth and Tall Waterhemp – Growth and Development” can be found at Detailed descriptions also accompany the photos. To access the notes, open the file in Adobe, click on “View,” scroll to “Comment,” then select “Annotations.”

Identification will be the key in reducing further infestation in Minnesota. For other articles on Palmer amaranth, see:

Tuesday, August 2, 2016

Free Waste Pesticide Collections

Collections available to eleven northwestern Minnesota counties

ST. PAUL, Minn. – The Minnesota Department of Agriculture (MDA) is hosting a series of free waste pesticide collections available to eleven northwestern Minnesota counties. Residents from Beltrami, Cass, Clay, Clearwater, Lake of the Woods, Kittson, Marshall, Pennington, Polk, Red Lake, and Roseau counties may attend any of the four collection sites in mid-August.

Friday, July 22, 2016

Part 5 ----> Just the facts: A review of the biology and economics behind insecticide recommendations

Biology helps determine the profitability of crop production on your farm – Ignoring biology is expensive

None of what we have presented here is new, or groundbreaking information. However, all of what we have presented here is based on science that has been vetted and implemented over thousands of acres for more than a decade. Economic injury levels take commodity prices, labor and control costs into account. Fortunately, the biological components of an EIL are not sensitive to commodity or input prices. The insects on your farm do not eat faster or more when crop prices are high or insecticide costs are low; nor is your crop more sensitive to insect damage (remember the damage boundary). Yield loss occurs at the same level of pest population, regardless of market prices of commodities. It makes no sense to treat if there is no reasonable likelihood of damage.

Science is best when it does not sit still. New research on pest and crop biology and on new management tools may change EIL’s and associated ET’s over time. However, since the adoption of the 250 aphid/plant economic threshold, additional research has only confirmed the results of the original multi-state biological and economic research.

While some may view an insecticide costing "only a couple of dollars" as inexpensive when compared to other production inputs, it is still an added cost for no added benefit. These inputs add up with each acre applied. Farmers often find the "free" application costs when insecticides are tank-mixed with herbicides or other pesticides have unintended negative consequences - poor control from poor timing or application techniques of one or more products. Using an ET, based on sound, peer-reviewed research will help you apply your crop input dollars where they are most likely to produce a positive return on your investment and minimize the chances of creating other problems for yourself.

Using fear or faulty economic logic is tried and true as a very effective sales tool. It’s always prudent to be a skeptical consumer and consider the messenger when you evaluate information - a conflict of interest can arise if a profit motive underpins recommendations made without facts behind them. Be very wary of ETs that are based on "feel," eyewitness accounts, or other anecdotes that are not supported by hard scientific data. ETs that are radically different from those recommended by agricultural research universities are another red flag.

Hopefully, this article has provided you with information that will help you sort through the information clutter on TV, radio, print media and especially the internet. A list of research references is included in the complete article ( for those who would like to read and learn of some of the research supporting our soybean aphid management guidelines and economic threshold recommendations. Contact Extension for the most up-to-date and state-specific recommendations.

This is the 5th and final installment in a series on soybean aphid management and insecticide recommendations.  Previous installments covered how recommendations are created, how aphids hurt yield, the economics and biology of aphid insecticide recommendations, costs associated with early treatment and how to know if you have a soybean aphid problem.  A link to the complete document is provided in this installment or at ( .

Thursday, July 21, 2016

Part 4 ----> Just the facts: A review of the biology and economics behind insecticide recommendations

Costs of treating soybean aphids too early

While some newer insecticides target a narrower range of insects, most insecticide applications are not specific. They will kill beneficial insects (lady beetles, parasitic wasps, etc.) as well as pests, later allowing soybean aphid populations to rebound in fields without those beneficial insects to slow them down. By using the ET, natural enemies will have a chance to suppress the aphid population and possibly prevent it from reaching economically damaging levels. After application, insecticide residues will kill insects for a short time, but insecticide activity invariably declines over time (generally, this is considered a good thing). With most insecticides registered for soybean aphid control (such as pyrethroids), soybean foliage emerging after treatment is not protected. Insecticides that are absorbed and translocated within soybean plants typically move upward only a leaf or two and eventually leave unprotected foliage, especially when applied early in the season. 

Applying treatments early can result in a false sense of security and a reduced reliance on scouting. If a re-infestation is not detected before reaching the EIL, yield may be reduced. If detected, the cost of additional insecticide applications are incurred. Early treatment can reduce or eliminate the cost efficiencies of a single, well timed threshold-based treatment. Finally, unnecessary insecticide applications do nothing positive for a short-term return on investment. Importantly, long-term returns can be reduced if insecticide resistance becomes fixed in the soybean aphid population. This has happened many, many times in the history of pest management. We know that managing pesticide resistant pests is seldom "cheap and easy" (for example, consider the problems with herbicide resistant weed control).

Wednesday, July 20, 2016

Part 3 ----> Just the facts: A review of the biology and economics behind insecticide recommendations

Economics of soybean aphid infestations: Math and biology matter

Figure 1. Relationship of insect population and crop yield
 (Modified from Pedigo et al. 1986).

The lowest level of aphid infestation that has been shown to cause yield loss in soybean is several thousand aphid-days. This value, referred to as the damage boundary, is a biological relationship between the insect, crop, and environment, and is independent of crop and input costs. Below the damage boundary, no damage can be measured. Therefore, management efforts directed at treating aphid levels well below the damage boundary cannot provide a return on investment.

The economic injury level (EIL) is the point at which the yield loss from insect damage is equal to the cost of a management action, such as an insecticide application. Insecticide applications made to pest populations that have not reached this point, and are unlikely to reach it, would not provide any return. To more readily apply this yield-loss relationship to field scouting and aphid management, a value in terms of aphids per plant was calculated as the threshold to apply an insecticide to threatening populations.

Tuesday, July 19, 2016

Part 2 ----> Just the facts: A review of the biology and economics behind soybean aphid insecticide recommendations

How can soybean aphids reduce soybean yield?

The soybean aphid feeds on the phloem fluids (sometimes referred to as "sap") by inserting piercing-sucking mouthparts directly into the phloem vessels that carry products of photosynthesis from the leaves to other parts of the plant. Prior to feeding, aphids "taste" the sap to determine if the plant is a suitable host species and if the quality is acceptable. Once they settle and begin feeding, the injury from soybean aphid infestations can reduce plant growth, pod number, seed number, seed weight and seed oil concentration (2, 24). Early and prolonged aphid infestations can affect all yield components, while later infestations tend to only reduce seed size (2). In addition, soybean aphids decrease photosynthesis rates of soybean plants (11).

Direct yield loss from soybean aphid feeding does not occur when the first (or five or ten) aphids begin feeding. Today’s soybean varieties are equipped to handle minor challenges, including a few aphids. Yield loss from soybean aphid is related to how many soybean aphids are present and for how long the aphids are present and feeding. The amount of aphid population pressure over time is calculated as aphid-days. Simply put, this is the average number of aphids on a plant multiplied by the number of days they are present. A single soybean aphid on a plant for 10 days is equal to 10 aphid-days, 200 aphids on a plant for 20 days is equal to 4,000 aphid-days, and so on. This aphid-day concept proved to be a good indicator of how soybean yield responded to aphid populations (23).

Monday, July 18, 2016

Northwest Research and Outreach Center | Crops and Soils Day | Wednesday, July 20, 2016 | Registration @ 7:45

Just the facts: A review of the biology and economics behind soybean aphid recommendations

Before soybean aphid was identified as a pest of soybean in the U.S. in 2000, insecticide applications to northern soybean crops were rare, targeting sporadic insect and mite outbreaks. Although large infestations have been relatively uncommon since the early to mid-2000’s, the soybean aphid is unquestionably still the key insect pest of soybeans in many North Central states. A tremendous amount of research and observational data has been obtained for this pest since its introduction and we have the tools and the knowledge to manage this pest effectively.

The question is where to get the best information? There is a wide array of pest management advice and information available for soybean producers. The internet is particularly rife with newsletters, social media postings, and videos that all purport to give expert advice. It’s wise to always consider the source of the information and also evaluate what it is actually based on - making a statement with absolute certainty doesn’t necessarily make it a fact. As scientists at universities, we make pest management recommendations that are based on repeated and controlled studies, statistical tests and, ultimately, a system called “peer review” that ensures that what we publish is vetted thoroughly and evaluated by other scientists, often anonymously. However, for many of the sources of information available to soybean farmers, there is no review of any kind. As a result, many of the “recommendations” from entities not relying on sound science are never challenged or critically evaluated. As such, they are just opinions.

The Land-Grant University system and the Extension mission were created to conduct unbiased research and provide education for the public good. The soybean aphid management recommendations from Land-Grant Universities are based on replicated research that is evaluated by other agricultural researchers and educators (peer-reviewed) before it is published and disseminated. These recommendations aren’t just anecdotal, or based on hunches and feelings. They’re based on facts, established crop and pest biology, effectiveness of single or combined management tactics, short- and long-term economic costs and environmental implications.

As farmers and their advisors begin to find soybean aphids in their fields, the timing is right for a fact-based review of what is known about soybean aphid, their effect on yield, and cost-effective management of this pest.

This review was a cooperative effort by entomologists from several North Central states. The data behind our discussion represent the research efforts of many more. Topics pertinent to insecticide as a management tool for soybean aphids will presented as a series of brief blog posts over the next few days.

prepared by:

  • University of Minnesota: Bruce Potter, Robert Koch & Phillip Glogoza
  • Iowa State University: Erin Hodgson
  • Purdue University: Christian Krupke
  • Penn State University: John Tooker
  • Michigan State University: Chris DiFonzo
  • Ohio State University: Andrew Michel & Kelley Tilmon 
  • North Dakota State University: Travis Prochaska & Janet Knodel 
  • University of Nebraska: Robert Wright & Thomas E. Hunt 
  • University of Wisconsin: Bryan Jensen 
  • University of Illinois: Kelley Estes & Joseph Spencer 

Thursday, June 9, 2016

Watch for Cereal Aphids in Winter and Spring Wheat / Small Grain Survey Maps for Minnesota and North Dakota

Cereal aphid Infestation levels in recent weeks 
illustrate the northward movement to HRSW 
from the earlier infestations of Winter Wheat in 
southern MN.
Field reports from Minnesota (MN) indicate that the cereal aphids reported in winter wheat in early May, many of which were treated at the time of herbicide/fungicide applications, are now moving to spring wheat in those southern areas of MN. Surveys are also detecting movement and colonization northward to central and northern HRSW areas of MN. In North Dakota and Minnesota, IPM Scouts are finding these increasing populations, so continue to scout fields for cereal aphid population buildups.

Small Grain Survey maps are now available on a weekly basis and can be accessed for viewing:
  • crop development
  • disease observations, both incidence (% infested plants) and severity (level of infection)
  • insect infestations

Links to the survey maps are at the top of the right column or can be found at:  

Wednesday, June 8, 2016

Weed identification

Whether you are a novice or a veteran, if you need some references for weed identification, here are some resources through University of Minnesota Extension. There are also many references available for your smartphone that you can take to the field.

Got weeds? U of M Extension has resources

Managing herbicide resistance and controlling resistant weeds is a challenge. The U of MN Extension Crops Team is offering new video and web resources to help manage these difficult to control weeds:
  • Weed management website – includes resources on herbicide resistance management, weed identification, herbicide application and chemistry, and research reports.
  • Herbicide resistant waterhemp (video) – Waterhemp has an extended emergence pattern, making it difficult to control. Results from a 2015 trial demonstrating the effectiveness of layering residual herbicides for herbicide-resistant waterhemp control are shown in this video.
  • Herbicide resistant giant ragweed (video series) – Due to its large seed and early emergence, giant ragweed can be difficult to control. This video series describes a study looking at alternative management practices to control this herbicide-resistant weed.

To see additional videos from the U of M Crops Team, visit:

Tuesday, April 12, 2016

Cold Temperatures and Burndown Herbicides

by Bob Hartzler
     Professor of Agronomy Extension Weed Specialist
     Iowa State University

published April 11, 2016
                Integrated Crop Management on line newsletter

The weather forecast appears to be favorable for field activities so people will be anxious to get into the field. A concern for many will be the effect of the widespread freeze on the performance of burndown herbicides. Unfortunately, there is no simple blanket statement that can be made since the plant response will vary depending on weed species, weed size, and the herbicides used.

Postemergence herbicides

A statement found on most postemergence herbicide labels is ‘Apply when weeds are actively growing.’ This is by far the most important consideration in determining whether to apply a postemergence product. Most weeds that emerge in March are adapted to sub-freezing temperatures and will not be killed by frost; however, it takes time for them to recover from these events. Performance of herbicides will be reduced if applied too soon following a frost. How long does it take to recover? Again, no simple answer since it depends on the weed species, severity of the frost, and weather conditions that follow the freeze. Closely monitoring the weeds for evidence of new growth is the best way to determine recovery.

Tuesday, March 22, 2016

U of MN researchers seeking soybean growers to cooperate on study of impacts of seed treatments on soybean aphid and parasitic wasps

by Jonathan Dregni (Scientist), Robert Koch (Assistant Professor & Extension Entomologist), and George Heimpel (Professor)

Insecticidal seed treatments are used widely in soybean production. As with any new pest control technology we need to examine the potential for unintended consequences (see more at 
The Effectiveness of Neonicotinoid Seed Treatments in Soybean). University of Minnesota entomologists are looking for farmer collaborators willing to help study insecticidal seed treatments by allowing researchers to monitor populations of aphids and parasitic wasps in soybean fields planted with insecticide-treated and untreated seeds. Please contact Jonathan Dregni, U of MN scientist, if you or a neighbor would like to be involved, or 651-207-3539.

Considerations when planting dicamba-tolerant soybean

by Lisa Behnken, Extension Educator, Fritz Breitenbach, IPM Specialist SE Minnesota, Jeff Gunsolus, Extension Agronomist, Weed Science, and Phyllis Bongard, Content Development and Communications Specialist, University of Minnesota

Monsanto's Roundup Ready 2 Xtend™ soybean, which is tolerant to both glyphosate and dicamba, is available for purchase this spring. While this will eventually offer another option for controlling glyphosate resistant and other tough-to-control weeds, it also brings up label and marketing concerns for the 2016 growing season.

Chomping at the bit yet?

prepared by Jochum Wiersma, UMN Small Grains Specialist

Although there is some snow in the forecast for tomorrow across much of Minnesota, the weather has been unseasonably mild and the frost is already out of the ground in many areas. The first reports of small grain being seeded reached me yesterday and that begged the question whether it is too early the seed small grains. In 2012, the last week of winter and first week of spring were also unseasonable warm. At that time I wrote a short article about the risks and rewards of early planting. Please check back here if you like reread the blog post and refresh your memory.

Thursday, January 14, 2016

Wednesday, January 6, 2016

2016 Private Pesticide Applicator Recertification Workshops

Listing of all workshops

Here are links to the brochures listing dates and locations of workshops by region:

For workshops in Northwest and West Central Minnesota (PDF)

For workshops in Southeast and South Central Minnesota (PDF)

For workshops in Central Minnesota (PDF)
Workshops in Paynesville (1/19), Little Falls (1/21) and Holdingford (2/11) have lunch options - see brochure for details. 

For Workshops in Southwest Minnesota (PDF) 

Things to be aware of for private pesticide applicator recertification:

Registration Continues for the 2016 Ag Professional Research Updates

By Dave Nicolai, Coordinator for the Institute for Ag Professionals

The 2016 Ag Professional Research Update Sessions are scheduled for these locations: Waseca (Jan 5), Kasson (Jan 6), Lamberton (Jan 7), Morris (Jan 12), Willmar (Jan 13) and Crookston (Jan 14 ). On-line registration by site is listed below. The registration fee is $45 through Dec 31st and $50 after Jan 1st. Registration will be available at Noon; start time is 12:30 pm. The program continues until 4:40 pm. Please refer to the Institute for Ag Professionals Research Update web page for additional information and registration as well. At the 2016 University of Minnesota Research Update for Ag Professionals, you will find research-based strategies to deal with today's changing pests, diseases, varieties, and nutrient and environmental recommendations. Presentations and discussions at the update will allow you to visit with experienced university researchers and offer you the opportunity to visit with colleagues to discuss topics of interest to you in your region.

Read more »

New publication on Role of Neonicotinoid Seed Treatments in Soybean Production

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

Neonicotinoid seed treatments are used on a large percentage of soybean acres. However, the value of these treatments was questioned in a 2015 EPA report. In response, field crops entomologists from 12 northern states, including Robert Koch and Bruce Potter from the University of Minnesota, collaborated to create a new multipage extension publication, entitled The Effectiveness of Neonicotinoid Seed Treatments in Soybean, which explains the role of neonicotinoid seed treatments in northern soybean. 

Neonicotinoid seed treatments can be a useful tool for management of some early-season soybean pests in targeted high-risk situations. However, the current widespread use of these treatments exceeds the risk posed by pests and may cause adverse consequences, such as impacts to beneficial organisms, such as predatory insects, and lead to development of pest resistance. 

For the full discussion, see The Effectiveness of Neonicotinoid Seed Treatments in Soybean.

Central, Western, and Southern MN Small Grain Winter Workshops

University of Minnesota Extension is offering five Small Grain Winter Workshops in Central, Western, and Southern MN in January and February to address small grain production.

Click here for copy of brochure