Recently in the Soybean Category

By Liz Stahl and Jeff Coulter

Daniel Kaiser

University of Minnesota Soil Fertility Specialist

Research on Iron Deficiency Chlorosis (IDC) has been identifying methods to manage the problem for soybeans. Since 2010 research has been conducted using strip trials within farmers' fields. Currently we are looking for a 5 acre area to conduct a field study looking at the effect of Soygreen and oat cover crops on areas of the field that range from no-IDC to severe IDC. Our goal is to determine the economic benefits of the treatments on varying IDC severity within fields planted with two soybean varieties with varying tolerances to IDC.

Learn how conservation tillage can save soil, time, fuel -- and money.

University of Minnesota Extension will host the seventh annual Conservation Tillage Conference and tradeshow Feb. 7 and 8, at the International Event Center in Rochester, MN.

The day-and-a-half-long conference will provide practical, how-to information on nearly every aspect of conservation tillage. Learn how conservation tillage can save soil, time, fuel -- and money. Besides saving valuable soil resources, conservation tillage has been proven to save $25-45/ac in tillage costs. And that's not including your time.

The day-and-a-half-long conference will provide practical, how-to information on nearly every aspect of conservation tillage.

"Whether you are an experienced steward looking to fine-tune what you are doing, a crop consultant who helps growers, or a novice looking to get your feet wet, you should put this conference on your calendar now," says Jodi DeJong-Hughes, Minnesota Extension tillage specialist and conference coordinator.

Experts from the University of Minnesota, neighboring states will present the results of extensive research comparing tillage systems, including strip tillage. In addition, experienced conservation tillage farmers will answer questions and provide management tips.

Conference topics include:

• Precision Ag solutions


• Weed species shift and control


• Nutrient management in high residue systems


• Strip intercropping management


• Soil health with reduced till systems


• Vendor Sessions: Learn about new equipment, cover crops and technology

The popular "Farmer Panel" will be back again, offering practical insights and management tips from experienced northern strip tillers and ridge tillers.

Also back is "Beer & Bull," your chance to pick the brains of other farmers, consultants and researchers in a relaxed, informal setting.

The conference will open with a provocative keynote speech from Robert Recker: "Yield, Profitability, and Sustainability: Where to go from here?" Bob is the owner of Cedar Valley Innovation and a retired John Deere engineer, researching strip intercropping. He studies corn growth on a row by row basis trying to unlock the secrets of using technology and the sun to farm smarter.

The Conservation Tillage Conference runs from 9:00 a.m. to 4:30 p.m. on Tues., Feb. 7th, and from 8:00 a.m. to 12:15 p.m. on Wed., Feb. 8th. The tradeshow will be open both days.

The registration fee is $150 per person, which includes nine continuing education units (CEUs). An early bird fee of $120 per person is offered for those registering by Jan. 25, 2012.

More information, including schedules, maps, contacts and exhibitor registration is available at www.TillageConference.com. Or contact Jodi DeJong-Hughes at 320-815-4112 or dejon003@umn.edu.

By Jennifer Obst, Minnesota Agricultural Experiment Station, 612-625-4741

A comprehensive comparison of most crop varieties grown in Minnesota is now available in print and electronic forms. Minnesota Varietal Trials 2012, published by the Minnesota Agricultural Experiment Station, provides the results of the 2011 University of Minnesota evaluation of more than 1000 individual entries of plant varieties.

Soybean College

on the campus of University of Minnesota - Crookston
Crookston, Minnesota

Tuesday, December 20, 2011

8:30 a.m. to 3:10 p.m.
(Registration begins at 8 a.m. in Bede Ballroom, Sargeant Student Center)

click here for a copy of the Soybean College 2011 Brochure for registration information

By Daniel Kaiser
Extension Soil Fertility Specialist

U of M Nutrient Management Website

A new nutrient management website has been launched that houses most of the current fertilizer suggestions and data from the University of Minnesota. This website was made possible by funding from the Minnesota Agricultural Fertilizer Research and Education Council and was put together through a joint effort for several researchers from the University of Minnesota who's research focuses on nutrient management issues for several crops growth throughout the state of Minnesota.  We would like to thank the AFREC program because without them this effort would not have been possible

Soybean Yield Loss Estimates from Early Frost
Seth Naeve - Extension Soybean Agronomist

Few resources are available to producers and agricultural professionals relative to yield losses from late- season frost injury to soybean plants. A study investigating the risks and benefits of long-season soybean varieties was established in 2008. This work was carried out by the Naeve Soybean Production Project, and was funded by the Minnesota Soybean Research & Promotion Council. While we don't have all of the answers that folks search for after a late-season frost, a small piece of this research effort is described below.

In 2009, 2010, and 2011 soybean plots were established to investigate the yield effects of early frost on a range of soybean maturities. Three varieties with maturities of RM 0.8, 2.0, and 2.8 were examined in 2009. These were planted at a normal seeding date (around May 1) and at a late planting date (around May 21). Frost was simulated with applications of Liberty herbicide at a rate of 32oz per acre in 10 gallons of water on September 7 (early) or September 21 (late). In 2010 and 2011, five varieties ranging from MG 0.8 to 2.8 were planted at a singleplanting date (early May) and treated to simulate frost on three dates (approximately September 7, 14, and 21).

Photo of a soybean plot 'frosted' with Liberty approximately 10 days prior. In the left of the photo is a soybean plot 'frosted' 3 days prior.

By Seth Naeve and Dave Nicolai University of Minnesota Extension

A hard frost occurred early Thursday morning (Sept 15^th) across much of central and southern Minnesota.  The complete effects of this frost or freeze event may not be known for some time.  However, most soybean and corn fields have not reached physiological maturity.  Yield and quality in these fields were likely affected. 

Northern Minnesota Soybean Growers (and our neighbors in the Dakotas) have the opportunity to attend a wide range of Variety and Research Plot tours the first week of September. The attached flyer lists ALL the upcoming plot tours for summer-fall. Next up, are the . . .

written by Dr. Jeff Stachler, Weed Scientist, UMN and NDSU

Scouting fields for weeds throughout the growing season is extremely important to maintaining herbicide effectiveness and planning for future weed control decisions. Scout fields now and at harvest to determine the effectiveness of this season's weed control practices. If weeds are present now, determine why they are present. If weeds are present due to herbicide resistance, then weed control and cropping practices must be different next season and beyond.

What does soil quality mean? Why is it so important? How do we measure it and how can we impact soil quality with our management practices? Hear experts from the University of Minnesota, Ohio State University, the USDA-Agricultural Research Service, and the USDA-Natural Resource Conservation Service address these questions and more at the "Soil Quality Workshop". This program will be held at two locations: Monday, September 12 at the West Central Research and Outreach Center in Morris, and Tuesday, September 13 at the Southern Research and Outreach Center in Waseca. Each workshop will start with check-in at 8:00, with the program running from 8:30 to 4:30. This program is sponsored by U of MN Extension, The Ohio State University, the Minnesota Department of Agriculture and North Central Region Sustainable Agriculture Research and Education.

By Dean Malvick

Questions about which soybean diseases will be problems this year in Minnesota come up often. Although there are no good predictive systems, the wet weather conditions this summer are favorable for sudden death syndrome (SDS) and Phytophthora root and stem rot.  Phytophthora rot occurs across MN.  SDS occurs most often in southern MN, but appears to be spreading north each year.

By Lizabeth Stahl

Hear the latest University of Minnesota research and information on strip tillage and see strip-tillage equipment in action through field demonstrations at the 2011 "Minnesota Strip Till Expo" on Friday, August 5th, at the College and University Center in Owatonna. This event will run, rain or shine, from 9:00 to 3:30, with registration and Exhibits starting at 8:30. Admission to the Expo is free and food will be available for purchase on-site. This program is brought to you by U of MN Extension and Riverland Community College.

update prepared by Dr. Ian MacRae, UMN Extension Entomologist, NWROC-Crookston

Many field projects are underway and we're scouting small grain and soybean fields to stay on top of what is happening with aphid populations in these crops. Following are comments based on what our field visits are revealing in northwest Minnesota.

What is the tour about? Viewing plots for Managing glyphosate-resistant waterhemp throughout the crop rotation, especially sugarbeet and soybean.

By Doug Holen and Phil Glogoza, University of Minnesota Crop Extension Educators.

Producers have been pushed to accomplish as much planting possible in the little time given as calendar dates roll by in a late spring start.  The goal has been to get the seed in the ground when fields are ready for equipment and between rain events.  It has been common across the state in previous years for producers to ground roll fields within hours of planting soybeans.  However, the push to plant between rain events and other delays this year has left many fields unrolled.  The question is, "Can I still roll without causing significant damage to the plants or stand?"      

By Dave Nicolai and Seth Naeve
Originally published in Ag News Wire

With only 28 percent of corn acres planted prior to May 9 in Minnesota, growers face the difficult decision of when to begin planting soybeans in order to maintain adequate yields.

Soil conditions are of primary importance when considering delayed planting.

Soil conditions and soil temperature

Soil conditions at and after planting usually make a difference in how successfully the crop is established. Soil compaction and smearing is a concern when pulling implements and the planter through, or driving on, wet soil.

To limit soil compaction, keep axle loads under 10 tons and properly maintain air pressure in the tires. Not only does this help the soil, but it will help your tractor run more efficiently and with less slippage. On wet soils, use the lightest tractor that can get the job done.

Soybean has delicate seed, so it benefits when planted about 1 1/2 inches deep, modestly firmed into the seed furrow, covered by relatively loose soil, and into soils with temperatures of 60 to 70 degrees. As of May 9 , soil temperatures at the 2-inch depth averaged 61 and 56 degrees, respectively, at University of Minnesota Research and Outreach centers in Lamberton and Waseca.

The lack of oxygen in saturated soils and the formation of a soil crust of even modest strength can almost eliminate soybean emergence. Therefore, it is important to pay attention to the five-day forecast prior to planting. Planting in cool and wet conditions may lead to poor germination and seedling diseases such as pythium. These problems are magnified by extended cold and rainy periods after planting.

University of Minnesota Extension research indicates that, under ideal conditions, soybeans in southern Minnesota should be planted at about 140,000 live seeds per acre (see Table 1). Soybeans grown in central and northwestern Minnesota require harvest stands of approximately 125,000 to 150,000 plants per acre to maximize yields. This is likely due to shorter-statured soybeans with fewer total nodes that are often produced in these regions. Increased seeding rates are required in central and northwestern Minnesota.

Planting date and soybean yield

Since early-May plantings usually result in maximum yields, lower yields should be expected for later plantings (see Table 2). Planting soybeans in Minnesota on May 10 results in only a 2-percent yield loss; on May 15 in a 3-percent yield loss, and on May 20 in a 6-percent yield loss (or 94 percent of normal yield).

For more educational information and tools, visit www.soybeans.umn.edu, a cooperative effort among the University of Minnesota, University of Minnesota Extension, and the Minnesota Soybean Research and Promotion Council. More information about delayed crop planting can be found at www.extension.umn.edu/agriculture/crops/late-planting.

Waterhemp is an annual weed species in the pigweed family that is capable of producing greater than 1 million seeds per plant and due to a limited number of effective herbicides, especially in sugarbeet and soybean, is difficult to control compared to most weed species.  In addition to the production of large quantities of seeds, continual germination throughout the growing season and an increased frequency of herbicide-resistant biotypes adds to the degree of difficulty in keeping this weed species under control.  The good news is that the longevity of waterhemp seeds in the seedbank is relatively short compared to most species (1 to 12% survival after 4 years), meaning complete control (zero seed production) of all plants over a three to four year time period should significantly reduce the waterhemp seed bank densities, allowing the farmer to take control of this difficult weed problem.

U of M Conservation Tillage Conference in Fergus Falls, Feb. 9-10
By Jodi DeJong-Hughes, Extension Educator, Crops

Learn how conservation tillage can save soil, time, fuel -- and money.

University of Minnesota Extension will host the seventh annual Conservation Tillage Conference and tradeshow Feb. 9 and 10, at Bigwood Event Center, 921 Western Avenue, Fergus Falls, Minn., just off U.S. Interstate 94.

The day-and-a-half-long conference will provide practical, how-to information on nearly every aspect of conservation tillage.

"Whether you are an experienced steward looking to fine-tune what you are doing, a crop consultant who helps growers, or a novice looking to get your feet wet, you should put this conference on your calendar now," says Jodi DeJong-Hughes, Minnesota Extension tillage specialist and conference coordinator.

Experts from the University of Minnesota, neighboring states and Canada will present the results of extensive research comparing tillage systems, including strip tillage. In addition, experienced conservation tillage farmers will answer questions and provide management tips.

Conference topics include:
•Matching tillage systems with soil types
•Weed species shift and control
•Nutrient management in high residue systems
•Residue breakdown strategies
•Tractor efficiency and traction
•Introduction to vertical tillage.

New at this year's conference:
•Stump the Tillage Specialists: Question tillage experts from Minnesota, North Dakota, Iowa and Wisconsin;
•Vendor Sessions: Learn about new equipment and technology.

The popular "Farmer Panel" will be back again, offering practical insights and management tips from experienced northern strip tillers and ridge tillers.

Also back is "Beer & Bull," your chance to pick the brains of other farmers, consultants and researchers in a relaxed, informal setting.

The conference will open with a provocative keynote speech from Bruce Vincent: "With vision, there is hope." Vincent is a third generation logger from Libby, Montana. "During the past 20 years, he has given motivational speeches throughout the U.S. and the world on how to educate consumers about agriculture in a truthful and balanced way," DeJong-Hughes says.

The Conservation Tillage Conference runs from 9:00 a.m. to 5:15 p.m. on Wed., Feb. 9th, and from 8:00 a.m. to 12:15 p.m. on Thurs., Feb. 10th. The tradeshow will be open on Feb. 9 only.

The registration fee is $140 per person, which includes nine continuing education units (CEUs). An early bird fee of $115 per person is offered for those registering by Jan. 31, 2011.

More information, including schedules, maps, contacts and exhibitor registration is available at www.TillageConference.com. Or contact Jodi DeJong-Hughes at 507-337-2800 or dejon003@umn.edu.

U of M Conservation Tillage Conference in Fergus Falls, Feb. 9-10

Learn how conservation tillage can save soil, time, fuel -- and money.

University of Minnesota Extension will host the seventh annual Conservation Tillage Conference and tradeshow Feb. 9 and 10, at Bigwood Event Center, 921 Western Avenue, Fergus Falls, Minn., just off U.S. Interstate 94.

The day-and-a-half-long conference will provide practical, how-to information on nearly every aspect of conservation tillage.

"Whether you are an experienced steward looking to fine-tune what you are doing, a crop consultant who helps growers, or a novice looking to get your feet wet, you should put this conference on your calendar now," says Jodi DeJong-Hughes, Minnesota Extension tillage specialist and conference coordinator.

Experts from the University of Minnesota, neighboring states and Canada will present the results of extensive research comparing tillage systems, including strip tillage. In addition, experienced conservation tillage farmers will answer questions and provide management tips.

Conference topics include:
•Matching tillage systems with soil types
•Weed species shift and control
•Nutrient management in high residue systems
•Residue breakdown strategies
•Tractor efficiency and traction
•Introduction to vertical tillage.

New at this year's conference:
•Stump the Tillage Specialists: Question tillage experts from Minnesota, North Dakota, Iowa and Wisconsin;
•Vendor Sessions: Learn about new equipment and technology.

The popular "Farmer Panel" will be back again, offering practical insights and management tips from experienced northern strip tillers and ridge tillers.

Also back is "Beer & Bull," your chance to pick the brains of other farmers, consultants and researchers in a relaxed, informal setting.

The conference will open with a provocative keynote speech from Bruce Vincent: "With vision, there is hope." Vincent is a third generation logger from Libby, Montana. "During the past 20 years, he has given motivational speeches throughout the U.S. and the world on how to educate consumers about agriculture in a truthful and balanced way," DeJong-Hughes says.

The Conservation Tillage Conference runs from 9:00 a.m. to 5:15 p.m. on Wed., Feb. 9th, and from 8:00 a.m. to 12:15 p.m. on Thurs., Feb. 10th. The tradeshow will be open on Feb. 9 only.

The registration fee is $140 per person, which includes nine continuing education units (CEUs). An early bird fee of $115 per person is offered for those registering by Jan. 31, 2011.

More information, including schedules, maps, contacts and exhibitor registration is available at www.TillageConference.com. Or contact Jodi DeJong-Hughes at 507-337-2800 or dejon003@umn.edu.

Heavy rain fell across much southern Minnesota on September 22nd and 23^rd and left large areas of Minnesota corn and soybean fields submerged.  Flood waters covered, perhaps 100,000 acres for several hours as rain water moved from fields into creeks and rivers.  Longer term flooding of fields affected tens of thousands of acres of cropland.  In most instances, drainage tile, where present,  were unable to prevent ponded waters.  In other cases, streams swollen by  4 -12 inches of rain falling on fields, roads and cities came out of their banks and flooded fields.

Dean Malvick, Department of Plant Pathology, St. Paul

The soybean crop is growing well across most of Minnesota.  As of July 25, 80% of the state's ~7.4 million acres of soybeans was flowering and 25% was setting pods. Most of the soybean crop in Minnesota was rated in good (58%) or excellent (27%) condition.  With the frequent rains this season, however, disease problems are appearing in some fields and others may be brewing.  The leaf diseases downy mildew, bacterial blight, and Septoria brown spot are common now in Minnesota, but fortunately none of these diseases typically cause significant yield reductions.  Many areas in Minnesota have also had favorable conditions for development of Phytophthora root and stem rot, stem canker, white mold, and sudden death syndrome. 

You are invited to a field day located along highway 71 between Olivia and Blomkest on the southeast corner of the intersection of U.S. Highway 71 and Kandyohi/Renville county line road. Discussions will focus on recent research on iron deficiency chlorosis and a tour of the research plot at this location. Registration for the event will begin at 9 am with speakers starting at 9:30.

Authors: Dimitre Mollov and Jennifer Flynn

When crops or plants are not growing well and look diseased or less vigorous than healthy plants, an accurate diagnosis of the problem may be critical to reducing and managing it. The Plant Disease Clinic at the University of Minnesota in St. Paul is open year-round to diagnose crop and plant problems and to assist with other plant testing questions. The Plant Disease Clinic welcomes samples from anyone and offers a wide variety of diagnostic and testing services.

After the recent stretch of rainy weather we are currently in a period of excellent conditions for finalizing postemergence weed control in soybean.  As crop stages progress, postemergence soybean herbicide options decrease due to growth stage or days before harvest restrictions.

U of M hosts Conservation Tillage Conference in Morton

University of Minnesota Extension will host the sixth annual Conservation Tillage Conference and tradeshow Jan. 27th and 28th, 2010, at Jackpot Junction, 39375 County Hwy. 24, Morton.

Conserve soil, time and fuel with conservation tillage. This conference will send you home with hands-on, how-to information in nearly every aspect of conservation tillage. Whether you are an experienced steward looking to fine-tune what you are doing, a crop consultant who helps growers, or a novice looking to get his feet wet, put this conference on your calendar now.

This year includes several of the leading industry and University researchers in the Northern Corn Belt. This 2-day conference and tradeshow will offer a full range of topics including:
¨ Weed species shift and control
¨ Crop production in no-till
¨ Soil physical characteristics and nutrient availability
¨ Government policy concerning reduced tillage
¨ Benefits and challenges of reduced tillage
¨ Corn nematode management
¨ Seed treatments and fungicide

The University of Minnesota and neighboring states have conducted extensive research comparing tillage systems, including strip tillage. In addition to the research-based presentations, a panel of experienced conservation tillage farmers will provide management tips and answer questions.

The program is packed with valuable information you won't want to miss. So make this year's Conservation Tillage Conference a must-attend session. The conference runs from 8 a.m. to 4:30 p.m. Jan. 27, and from 8 a.m. to 12:15 Jan. 28.

The registration fee is $125 per person, which includes continuing education units (CEUs). An early bird fee of $100 per person is offered for those paying by Jan 8, 2010.

More information, including schedules, maps, contacts and exhibitor registration is available at www.tillageconference.com.

Jodi DeJong-Hughes, Extension crops educator
phone: (507) 337-2816
email: dejon003@umn.edu

Ryan Miller, Extension crops educator
phone: (507) 529-2759
email: mill0869@umn.edu

By Dean Malvick, Department of Plant Pathology

Cool weather and low rainfall have held the soybean crop back in parts of Minnesota this summer. Now, significant diseases are a concern in some areas. Several diseases have started to appear recently that can significantly damage soybeans, especially sudden death syndrome (SDS), brown stem rot (BSR), and white mold. These diseases are favored by weather conditions that have occurred in large areas of Minnesota this season. The information we gather now can help to explain why yield may be low in some fields and can assist with targeting disease management where these diseases occur most often. There are no effective fungicide or other treatments that can be used this season to reduce damage from these diseases.

SDS has been reported at significant levels in Dodge, McLeod, and Waseca counties, and it is undoubtedly also appearing in other areas in Minnesota. Based on results from previous years, SDS probably occurs across much of the southern half of Minnesota, but it could occur anywhere in the state. Foliar symptoms of SDS have been developing for at least the past two weeks. The last two weeks of August and the first week of September is a good time to scout for SDS. Look for this disease first in low or compacted areas of fields and near field entry points. Initial symptoms are yellow areas on leaves, and these yellow areas turn into brown patches. Reports have indicated different levels of disease severity among some varieties. This would be a good time to look for different factors that could affect SDS severity, including soybean variety, tillage, drainage, crop rotation, and planting date. The map of the confirmed distribution for SDS in Minnesota, as well as more information and photos for SDS and other soybean diseases, can be found at the Minnesota Crop Diseases web site (www.extension.umn.edu/cropdiseases/soybean/index.html).

Foliar and stem symptoms of BSR are also starting to appear. BSR occurs in fields throughout Minnesota, including all areas where SDS occurs. When scouting fields or attempting to diagnose whether plants are infected with SDS or BSR, keep in mind that the foliar symptoms can look very similar for these two diseases. The key for BSR is to split the bottom 6" of the soybean stems and look for brown pith, especially at the nodes. Plants with BSR will have brown pith, but plants with SDS will have white pith. Keep in mind that plants with BSR always develops brown pith, but foliar symptoms (brown tissue between veins) do not always develop. The only way to know how much BSR is in a field is to split stems, and internal BSR stem infections alone can cause yield loss. BSR tends to be more severe when temperatures are cool (60- 80°F) during reproductive growth stages. When leaf symptoms develop, they can be most severe when soil has been wet at early flowering to pod fill growth stages and dry during maturation. The conditions in large areas of Minnesota appear to have been favorable for BSR this season.

White mold may also be significant in some parts of Minnesota based on growing conditions this year. We have had reports of white mold damaging and killing in several areas of Minnesota. This disease is favored by cool temperatures and rainfall from mid- July through August. All of Minnesota has had cool conditions, and the areas that received enough rain to maintain wet soil for short periods in July and early August are set to develop white mold. Look for scattered and patches of dead and dying plants, and the presence of white moldy growth and sclerotia (black to gray round to oblong structures up to 1/4") on and inside the stems. As with the other diseases, look to see if you can associate the more severe areas with factors that may affect white mold such as soybean variety, manure or fertility history, tillage, row spacing, or high plant population.

Finally, downy mildew is common in a number of areas. Although this soybean leaf disease rarely if ever reaches levels that damages yields in Minnesota, it can be fairly easy to see. Downy mildew typically only infects leaves at this time of the season, although later it can infect pods. Symptoms of downy mildew on the tops of leaves are irregular yellow to brown spots, and the bottom of the leaves under the spots have tan to gray tufts of fungal growth that can be seen easily with a hand-lens.

Is glyphosate less effective than 10 years ago?

Can you recognize the presence of glyphosate-resistant weeds in a field?

by Phillip Glogoza, Extension Educator, Crops

Management decisions on whether to treat soybean aphids will be affected by the soybean growth stage in a field during the next two weeks. As plants progress to the later reproductive stages (e.g., R5, R6, R7, etc.) risk of yield loss from aphids declines. Currently, the soybean crop ranges from R3 to R5. Insecticide treatments for R5 stage soybeans may respond positively to soybean aphid treatments when populations exceed threshold, however the level of the yield response is less predictable. Early R5 treatments are more likely to realize a positive response than late R5 treatments. Treatments for aphids are generally not recommended beyond the R6 growth stage.

By Ken Ostlie and Bruce Potter

Reports of spider mite infestations continue from both soybean and corn, particularly from areas with prolonged drought.  Even if you've received rain recently, check for mite activity along field edges to determine if you've got a building problem.  You may need to factor spider mites into a soybean aphid spray decision.

The article is available on the web at: http://swroc.cfans.umn.edu/SWMNPEST/09publications/spidermite.pdf.

Well so much for the relatively arthropod pest- free growing season.

by Dr. Ian MacRae, U of MN Extension Entomologist

There has been increasing pressure to apply insecticide and tank mixed pesticides at lower thresholds based on claims of increased yield benefits. While increased commodity prices can stimulate the desire to decrease risk tolerance and increase the use of pesticides, this is not always a paying proposition.

by Dr. Ian MacRae, U of MN Extension Entomologist

.... Low populations of Soybean Aphid (SBA) have been reported throughout NW MN and NE ND. Populations are still low and generally not on more than 30% of the plants. The cooler weather will slow reproduction for a few days but it is predicted to warm up by the weekend, at which time we'll start to see some more population growth and dispersal across fields. Although most fields are well below treatment levels so far, it is time to start scouting the soybean fields, getting a handle on what populations you may have and tracking progress and population growth.

by Dr. Charla Hollingsworth, U of MN Extension Plant Pathologist

In 1954, the first detection of the soybean cyst nematode (SCN) occurred in North Carolina. Since that time, the nematode has become the most important disease issue of soybean in the world. Spread with soil, this microscopic roundworm continues to gain ground in Minnesota soybean-producing areas. Essentially anything that can move small particles of soil will also transport this nematode.

by Phillip Glogoza, Extension Educator - Crops

Soybean rust was found in 392 counties in the United States in 2008. This is the highest number of counties reporting the disease since it was first discovered in the continental U.S. in 2004. Soybean growers in Alabama were encouraged to use fungicides on at risk beans in late August, many neighboring states reported mostly low infection levels throughout the month of September as the crop matured.

Glyphosate-resistant biotypes of giant and common ragweed and common waterhemp have been confirmed in Minnesota and are listed on the International Survey of Resistant Weeds web site at: http://www.weedscience.org/in.asp Both species appear to be resistant to approximately four-times the labeled use rate of glyphosate (4X).

In the short time frame presented to us during the growing season, separating glyphosate nonperformance due to resistant weed biotypes from other factors is an inexact and qualitative process but a quick response could help reduce the spread of glyphosate resistant weeds and set-up long-term management plans.

We are into the fourth year of a soybean date planting trial at Crookston investigating how two different relative maturity soybean varieties respond to planting date. Results for 2006 - 2008 show maximum soybean yield when planting in the May 1 – 15th window of opportunity. Previous planting date trials from the University of Minnesota also show an optimum planting window of May 10 – 20 to achieve maximum yield (Table 1).

Large populations of volunteer corn are being reported in some fields in Minnesota this year. What impact the volunteer corn will have on this year’s crop yield and the viable management options available will depend upon in which crop the volunteer corn is present. Making the assumptions that the majority of the volunteer corn present is glyphosate resistant and that glyphosate resistant crops were planted in the field this year, your only management option in corn at this time is cultivation. In soybean you have the herbicide options of the ACCase inhibiting herbicides such as: Select Max (clethodim), Fusilade DX (fluazifop-P), Fusion (fluazifop-P & fenoxaprop) and Assure II (quizalofop); note Poast Plus (sethoxydim) is not as active as the other herbicides on volunteer corn. The ACCase inhibiting herbicides are generally targeted on 12- to 24-inch tall volunteer corn. The ALS herbicide, Raptor can also effectively control smaller (2 to 8 inch) volunteer corn.