Research Projects

MSR&PC invests in research to provide Minnesota soybean farmers with valuable growing information to help increase yields and profitability. Through this research, soybean production today thrives on strong use of biotechnology, advanced breeding and on-farm agronomics that enable farmers to raise more bushels with fewer inputs and a smaller carbon footprint.

Soybean research is essential to keeping Minnesota soybeans competitive. MSR&PC funds research in new variety development, disease management, pest control and many other areas that affect yield and soybean value.

Learn more about this research investment on behalf of Minnesota soybean growers.

Research Videos

Research Project Executive Summaries

+ Effects of Corn Management on Subsequent Soybean Yields

podcast iconResearchers: Seth Naeve and Bruce Potter
Budget: $25,000

This study investigated the mechanisms behind the previous effect with a focus on the interactions between corn inputs and the increased soybean yield produced. The study will examine fertilizers applied to corn and their effect on the subsequent soybean crop with a focus on the productivity of the corn crop as a main factor. Corn population is used as the driver behind productivity. To do this, a factorial design was laid out as a split-plot, with nitrogen as the main plots, and sulfur, other macro and micro nutrients, and corn populations nested in a factorial design as the split plots. Corn was seeded at either 15,000 or 38,000 plants per acre. Nitrogen will be applied as either the N recommendation or N recommendation plus 40# as side-dressed N. Other macros (P, K, and Na will be provided at sufficiency by soil test or a build plus maintenance regime. Sulfur is applied to corn as a side-dress ATS program and balanced with an equal amount of N as UAN (28%in non-sulfur plots.

+ Effects of Tile Drainage on Soybean Yields and the Interactions Between Drainage and Modern Soybean Genetics and Management

podcast iconResearchers: Seth Naeve, Jeff Coulter, Gary Sands, Senyu Chen
Budget: $87,340

The objective of this project is to establish corn and soybean plots at the Minnesota Lake site. To best utilize this valuable resource, we propose to establish a series of soybean experiments on the site that will act as preliminary investigations for long-term research studies to be established in 2013.

The plan is to replicate three research studies that are supported by the United Soybean Board (USB) project “Agronomic Maximization of Soybean Yield and Quality” (a nine-state production project led by Seth Naeve) at this site under both well-drained and poorly-drained conditions. Utilizing the exact same research protocols used in this large, multistate project will help leverage dollars invested by the USB to maximize the impact of MSR&PC funds. The USB project provides a perfect jumping-off place for this drainage work as it provides broad and multifaceted protocols that contain a near-perfect suite of treatments for surveying the potential management interactions with drainage. In addition to the three large studies (totaling 42 treatments), we plan to establish an Soybean Cyst Nematode (SCN) study looking at chemical nematicides (canola meal). This study examines three rates of canola meal under both corn and soybean plots. In soybean, both SCD-resistant and susceptible cultivars will be utilized.

+ Request for Equipment Support for the Soybean Production Project

podcast iconResearchers: Seth Naeve
Budget: $27,655

This proposal represents an extension of the project entitled “Research to Maximize Yields in Minnesota.” This grant will provide the year two lease payment that is due to John Deere on December 9, 2012. This $50,000 grant supported the year-one lease as well as the purchase of ALMACO software allowing our research planter to plant by GPS rather than by cable-and-button system that we have used on this planter in previous years.

In 2010 and 2011, Naeve was able to utilize tractors located on Research and Outreach Centers to plant research studies there. However, because both tractor operators are in great demand during the spring, scheduling days to plant was problematic and delayed planting of each study at each site. In some cases, this delay was very significant. Having a tractor dedicated to planting soybean research trials is essential for the Production Project as its research continues to grow. Moreover, utilizing an ROC tractor is not an option for planting research, off-station.

Soybean production research at the University of Minnesota continues to gain momentum. Research investments by the MSR&PC and the USB are providing a rich base of soybean physiology and production studies from which to gain tremendous insights into optimizing inputs to maximize yields in Minnesota. Beginning in 2012, a 17 acre site near Minnesota Lake will become the first replicated drainage site in Minnesota. This on-farm research site will provide a vast quantity of valuable field data on drainage effects on soybean yield and quality. More importantly, however, this site will help identify interactions between drainage status of fields and management strategies so that soon, producers will be better able to optimize production on both well-drained and poorly-drained soils on their farms. Seth Naeve has also been the lead PI on a 3-year, 6-state USB supported project examining maximizing soybean yields in Minnesota and across the country. The USB Production Committee has agreed to extend this project to nine states for an additional three years (2012-2014), with Naeve as PI. This project carries a $1.5M budget over three years.

+ Phosphorus and Potassium Management for Soybean Rotated with Corn and Iron Chlorosis Management in Soybeans

podcast iconResearchers: Daniel Kaiser, John Lamb
Budget: $65,000

This project would assess the impacts of Soygreen and a companion crop on soybean yield affected by iron deficiency chlorosis (IDC) utilizing strip trial methodology. It would evaluate the potential impacts (agronomic and economic) from varieties with differing IDC tolerance across a landscape utilizing companion crops and/or Soygreen management strategies. We are looking to assess the impacts of IDC management strategy on quality (protein, oil and test weight) of soybeans.

Optimum phosphorus and potassium management is important due to the major need for these nutrients by crops. Efficient utilization of phosphorus and potassium is critical since prices in the past few years have been at an all-time high. We are looking to determine optimum phosphorus and potassium fertilizer application rates for soybeans rotated with corn. We will be evaluating the timing of broadcast P and K fertilizer application on soybean yield. We will seek to determine if starter fertilizer applied for corn can be used when P is broadcast for soybean to maintain yields of both crops. We will evaluate the impacts of P and K fertilizer rates and application timing on soybean quality and nutrient removal in grain. It would assess incline and decline rates of soil P and K as influenced by fertilizer rate and nutrient removal in grain.

We would have an evaluation of direct versus residual P application to soybean using strip trials. This part of the grant focuses on the question of whether soybeans benefit from direct application of P versus P applied before corn. Studies are already in place looking at the relative response for corn and soybean yields to soil test P.

+ Is Seed Fe Concentration Predictive of Resistance to Fe Deficiency in Soybeans?

podcast iconResearchers: John V. Wiersma, James H. Orf, James E. Kurle
Budget: $135,840

Through this research, we are seeking to confirm results from earlier research that identified seed Fe concentration as a consistent, reliable measure of resistance to Fe deficiency. We are looking to evaluate the potential of conventional plant breeding to increase seed Fe concentration, as a means of improving resistance to Fe deficiency. The research will seek to determine whether the Fe contents of whole seed of or seed components (embryo, cotyledon, or seed coat) can be used as an indicator of successful (non-chlorotic) seedling establishment. We are looking to answer if molecular markets can be associated with increasing planting seed Fe concentrations and also whether genotypes rank the same for seed Fe concentration when grown at Rosemount and Crookston.

The information gained in this project will be useful in 1) providing growers an additional trait to aid in variety selection; 2) improving resistance to Fe deficiency in elite lines developed by the UM Soybean Breeding Project; and 3) identify a minimum amount of Fe needed for early-season crop development.

+ Biological Control of Soybean Aphid

podcast iconResearchers: George E. Heimpel
Budget: $63,700

The research will seek to explore behavioral responses of soybean aphids and natural enemies to soybean plants with host-plant resistance and insecticidal seed treatments. In past and ongoing work, we have focused on interactions that occur once aphids and biological control agents have colonized these different categories of soybean plants. These studies have shown mixed levels of compatibility and incompatibility. Here, we take a step back and ask how likely it is that aphids and their natural enemies will colonize plants in the first place. To this end we have developed a laboratory bioassay system in which insects are released into a white box within which they are given the choice of colonizing with four different potted soybean plants. Preliminary studies using this bioassay system suggest that winged soybean aphids are reluctant to accept seed-treated plants. This trend was not seen for Rag1 resistant plants. Further understanding the behavioral responses of soybean aphids and their natural enemies to resistant, seed treated and control plants will lead to a more complete understanding of how these management tactics control aphids.

We will also be evaluating Aphelinus parasitoids of soybean aphids: assessing and developing a new group of biological control agents. We will focus on two important, novel developments with respect to Asian parasitoids of soybean aphids. The first is the discovery of a new Asian parasitoid species – Aphelinus certus— in Minnesota last summer, and the second is the likely permission to release a new species of Asian parasitoid in Minnesota: Aphelinus nr. Engaeus. Our objective for the field season of 2012 will include monitoring for Aphelinus certus throughout the soybean growing areas in Minnesota and also determining the extent to which it can control soybean aphids in the field. The second parasitoid, Aphelinus glycine, is in the final stages of passing through the federal permitting process.

+ Evaluating Soybean Plant Introduction and Breeding Lines for Resistance to Major Yield Limiting Fungal Diseases Found in Minnesota

podcast iconResearchers: James E. Kurle, James H. Orf
Budget: $42,364

This project identifies sources of resistance that are incorporated into new soybean lines developed by the soybean breeding program. Breeding lines exhibiting improved yields and desirable agronomic qualities are continually evaluated for their performance in either field or controlled environments (greenhouse and growth chambers) by inoculating plants with spores or conidia of the pathogens isolated in Minnesota. The research proposed in this grant proposal will be conducted in either a greenhouse or growth chamber.

This research would seek to optimize methods and conditions for evaluation of resistance to: 1) Fusarium virguliforme, root infection, vegetative foliar symptoms – mixed inoculum and reduced inoculum density germination to 21 day/R stage – fungal toxin and mixed inoculum; 2) Phytophthora sojae, Rps gene – stem inoculation and tolerance – layer method. 3) Sclerotinia sclerotiorum, cut petiole and broadcast mycelium.

We are seeking to use the procedures above to conduct disease resistance evaluations of soybean cultivars, PIs and breeding lines for resistance to: 1) Fusarium virguliforme; 2) Phialophora gregata; 3) Phytophthora sojae; and 4) Sclerotinia sclerotiorum.

This research will ensure development of disease resistant or tolerant cultivars for Minnesota growers. Results of the controlled environment evaluations will, whenever possible, be correlated with results obtained from field trials conducted both in MN and regionally to confirm the validity of the resistance evaluation techniques. This research is being conducted in close collaboration with the U of MN soybean breeding program and ensures: 1) that cultivars developed in the breeding program possess resistance to diseases occurring in Minnesota; 2) disease resistant cultivars are available to Minnesota growers and; 3) identifies germplasm with disease resistance characteristics to be used in future breeding efforts either directly or to validate results of marker assisted breeding efforts.

+ Occurrence and Identification of Pythium Species in Minnesota Soybean Producing Areas

podcast iconResearchers: James E. Kurle
Budget: $33,596

This project will identify the Pythium species that are present in a representative sample of soils from Minnesota soybean growing areas and will determine their occurrence and prevalence. The Pythium isolates will be evaluated for their pathogenicity on selected public and private soybean cultivars to determine if resistance is present in these cultivars. Because current management recommendations emphasize the use of fungicidal seed treatments for limiting stand loss and damping off the isolates will best tested for their sensitivity to seed treatments mefenoxam, trifloxystrobin and azoxystrobin.

This research will provide a more complete understanding of the problems associated with early season stand establishment of soybeans. It will identify the Pythium species that cause seed and seedling rots in cold, wet soils. It will also guide development of disease resistant or tolerant cultivars for Minnesota growers. The information obtained from tests of fungicide sensitivity may explain the inconsistent performance of seed treatments will guide seed treatment recommendations, and suggest management strategies, improve soybean stand establishment and final soybean yield.

+ Revealing Critical Information for Managing Stem and Root Diseases of Soybeans

podcast iconResearchers: Dean Malvick
Budget: $58,660

Soybean production in all regions of Minnesota can be greatly affected by stem and root diseases, with yield losses ranging from minor to 50%. These are complex diseases and more research-based information is needed to improve management and reduce yield loss. Through this research, we will be seeking to determine which environmental factors increase Fusarium root rot caused by F. oxysporum and F. solani. We will also look to determine if root rot and plant damage is more severe when Fusarium root rot pathogens, Rhizoctonia, and/or brown stem rot interact; and if common fungicides can suppress these pathogens/diseases. We will be testing different methods to initiate high levels of white mold in field plots for research on management strategies. We will deliver management information for soybean diseases across Minnesota and conduct specialized diagnosis of unusual soybean disease samples from Minnesota.

In many cases, stem and root damage is unknown because the diseases are hidden from view. These diseases often cannot be managed and significant yield loss occurs. This proposal focuses on Fusarium root rot, white mold and interactions among root-infecting pathogens. Crop damage due to these diseases is influenced by factors including weather, crop rotation and crop stress. These are complex diseases and more research-based information is needed to improve management and reduce yield loss.

We expect the research plans in this proposal will lead to development of information needed to reduce stem and root diseases on soybean to improve yield and profitability in Minnesota.

+ SCN Resistance and Soil Fertility Management Effects on Nematodes and Crop Yields

podcast iconResearchers: Senyu Chen, Jeff Vetsch, Seth Naeve
Budget: $100,000

Through this research, we are seeking to determine the effects of different sequences of SCN-resistance sources on dynamics of SCN-population densities and their virulence phenotypes (races or HG Types). We will look to determine the effect of organic chemical fertilizer application and tillage on SCN and other plant-parasitic nematodes. The research will look to determine interactive effects of plant-parasitic nematodes, soil fertilizer application and tillage on soybean and corn yields, and determine fertilizer and tillage effect on soil health by analysis of nematode communities as well as soil physical and chemical variables. This research will determine the effect of drainage, canola meal as organic amendment and SCN-resistance effect on SCN and other plant-parasitic nematodes. We will look to determine interactive effects of plant-parasitic nematodes, soil moisture and canola meal on soybean and corn yields, and determine the soil moisture and the organic amendment effect on soil health by analyses of nematode communities, as well as soil’s physical and chemical variables.

+ Soybean Breeding and Genetics Support

podcast iconResearchers: James H. Orf
Budget: $208,575

We are looking to continue developing soybean varieties adapted to Minnesota with improved protein, amino acid and oil content, acceptable levels of other quality characteristics, competitive yield and resistance to production hazards such as diseases, nematodes, iron chlorosis, lodging, etc. We are seeking to expand the development of special purpose soybean varieties for food and other uses adapted to Minnesota. We will continue testing public and private soybean varieties available or intended for sale to soybean producers in Minnesota and report results of yield, protein, oil, maturity and hazard reactions. The research will analyze advanced and preliminary breeding lines for seed components that have been genetically altered. Among the characters to be analyzed are amino acids, fatty acids, trypsin inhibitor, carbohydrates, phytate, lipoxygenase and other seed components of interest from a food or special use perspective.

A comprehensive soybean breeding and genetics program will effectively integrate field and laboratory approaches to produce innovative solutions to the challenge of improving the genetic potential of new soybean varieties. With the current interest in protein and amino acids as well as oil content, special emphasis is needed on breeding for increased protein, amino acids and oil content. In addition to new general purpose varieties, the development of special purpose varieties with value-added aspects has become of increasing interest to soybean producers as a way to increase profitability. As part of the breeding effort for developing soybean varieties, it is important to continually explore more efficient or better ways to breed soybean varieties that return more value per acre to the producers. Special breeding methodology studies using populations that are part of the variety development programs can help determine the best methods for public and private breeders to use in variety development. All of these aspects are a necessary part of a complete soybean breeding and genetics program.

+ Expanded Soybean Cyst Nematode and Other Variety Testing

podcast iconResearchers: James H. Orf, Senju Chen, Craig C. Sheaffer
Budget: $77,256

We propose that farmers be allowed to “nominate” soybean varieties to be included in the SCN and non-SCN tests (transgenic, conventional and special purpose). If the most popular or widely grown varieties are not entered by a company, these farmer nominated varieties would be entered with MSR&PC paying the entry fee currently about $250 per entry for non-SCN varieties and about $500 per entry for SCN varieties, which are then planted in three locations. We also proposed to expand the SCN testing to the northern zone in 2012. Not only are more farmers reporting SCN in northern Minnesota, but we need SCN information from northern sites. We have identified potential northern SCN sites in 2012.

Through this research, we will include farmer proposed varieties in SCN variety tests. We will evaluate 150 SCN varieties for reproductive index (indices) in SCN infested sites by collecting soil samples at planting and harvest, and for female index in the greenhouse with HG Type 0 (Race 3) and possibly other races. We will include farmer proposed varieties in other variety tests (transgenic, conventional and special purpose).

+ Traditional and Molecular Breeding for Soybeans Resistant to Cyst Nematode and Other Diseases

podcast iconResearchers: Nevin Young, James H. Orf
Budget: $86,268

We are targeting two main objectives to increase Minnesota soybean profitability related to SCN and other forms of disease resistance: 1) Continued breeding of Minnesota-adapted, SCN-resistant varieties through a combination of traditional and molecular breeding, including expanded use of novel sources of SCN resistance and; 2) Expanded use of multiplexed DNA markers with the following attributes: i) effective in early generation screening; ii) capable of distinguishing different forms of SCN resistance and; iii) effective at predicting resistance and agronomic performance at the time of crossing. As part of this work, our use of DNA marker technology will be expanded to address a broader range of disease and pest challenges faced by Minnesota growers.

We will carry out approximately 30 new soybean crosses with SCN resistant parents, many involving novel sources and leading to populations that form the basis for new resistant varieties approximately five to eight years in the future. We will process ~3,000 intermediate and advanced generation lines derived from earlier crosses, analyzed in the field and/or laboratory and leading to new varieties one to three years at a projected rate of one or two new releases per year. We will release one or two new SCN-resistant varieties for Minnesota growers in 2012. Through this research, we will implement more efficient DNA marker technology (TaqMan) that quickly and economically identifies SCN-resistant lines (including which forms of resistance has been inherited) early in the breeding program. We will use this technology to screen >3000 early and intermediate lines. We will continue the use of GoldenGate technology to discover new predictive markers that tag genes for novel forms of SCN resistance and extend this technology in breeding other forms of disease resistance and soybean quality traits.

+ Genetic and Environmental Control of Soybean Seed Quality

podcast iconResearchers: Seth Naeve, Jim Orf, Bob Stupar
Budget: $45,000

Soybeans grown in the northern and western ranges of the U.S. soybean production area are known for their low protein content. These soybeans are subsequently sold on both local and international markets at a significant discount over soybeans from “I” states and Brazil. In order to stay competitive, northern producers must simultaneously increase the protein level in their soybean crop while promoting the value that these lower protein soybeans provide to the end user. While the stakes are high, little progress has been made in this arena. We propose to change that.

We propose a multipronged approach to better understand and improve the value of northern grown soybeans. Within the past year, we have made significant advances in our knowledge of soybean quality, and we plan to utilize this knowledge and our unique resource base to begin to get to the heart of our protein and yield-limited soybeans. Meanwhile, we will demonstrate the variation in amino acid balance in soybeans, and utilize this knowledge to help demonstrate the true value of northern grown soybeans.

The objectives of this research request are to: 1) evaluate the effects of poorly drained and drought prone soils on soybean protein concentration; 2) evaluate environmental factors that contribute to the changes in amino acid balance of soybeans that vary in protein concentration; 3) utilize the six years of USSEC soybean quality data to model environmental effects on soybean composition; 4) develop markers for mutations affecting soybean seed quality traits, and; 5) develop five families of near isogenic lines that differ only fast-neutron induced mutations affecting seed quality.

+ Analysis of Soybean Fast Neutron Gene Deletion Mutants for Root Architecture

podcast iconResearchers: Gary J. Muehlbauer
Budget: $61,908

Roots are vital to the survival and health of plants. Roots provide not only nutrients for plant growth but also signal compounds for microbial, symbiotic and disease interactions (Vance 2011). Because plants are sessile organisms, the soil environment is explored through root growth and development. Root development and function have been extensively studied in Arabidopsis. However, nearly all of these studies have been done with two- to three- week old plants growing in the laboratory on agar medium. It is unclear as to how much of the information derived from studies of Arabidopsis can be translated to crop plants.

The research will seek to screen the fast neutron irradiated population under field conditions to identify useful phenotypes in symbiotic root nodule formation, root development and root architecture. We will look to rescue identified mutants and verify the heritability of any identified mutants. We will evaluate genomic changes in selected mutants through CGH and/or genome sequencing.

We expect to identify 200-300 fast neutron mutagenized soybean lines having altered root architecture and/or root nodule formation. Upon identifying these root phenotypes, we will confirm the phenotype and characterize how many genetic aberrations occur in each line.

+ Improvement of Soybean Seed Protein and Oil Through Genetical and Functional Genomics

podcast iconResearchers: Robert Stupar, Caroll Vance, Gary Muehlbauer
Budget: $81,600

Seed quality traits such as protein and oil levels are linked to genetic background and gene expression patterns during seed development. Association of molecular and genetic traits to seed phenotypes will assist soybean breeding efforts for improved seed quality traits. Identification and characterization of candidates for molecular and genetic regulation of protein and oil composition is important for future soybean improvement.

Our focus is on understanding and improving soybean quality traits with regard to seed development and protein/oil levels. We will seek to conduct high-throughput, next-generation sequencing on soybean mutant lines with contrasting seed protein content. This data will identify variations in genomic sequence that may cause differences in seed composition. We will initiate functional characterization of candidate genes that regulate seed protein and oil with the construction of targeted gene vectors and transformation into soybeans.

From the proposed studies, we will generate data on sequence polymorphisms and structural variation found in soybean fast neutron seed composition mutants. This data will provide sequence support for candidate regular genes that influence seed protein and oil content. In addition, vectors will be constructed to target two candidate genes in transformation experiments to test gene function in soybeans.

Previous studies supported by MSR&PC have been published (Bolon et al. 2010; Bolon et al. 2011) and presented at national and international meetings (please see below). The data generated from this proposal will be invaluable to ongoing and future research towards the identification of the genes and pathways that influence seed protein and oil content in Minnesota soybeans. High-throughput sequencing of soybean genotypes and characterization of novel candidate genes will be useful both for gene targeting and marker selection efforts toward the overall improvement and profitability of Minnesota soybeans, beyond improved seed protein and oil content.

+ Genetic Transformation For Soybean Improvement

podcast iconResearchers: Robert Stupar, Carroll Vance
Budget: $111,000

Soybean Iron Deficiency Chlorosis is particularly problematic in the calcareous soils of the upper Midwest and can cause significant yield losses. Therefore, IDC is a problem for many Minnesota producers. Development of soybean varieties with increased tolerance to IDC will benefit Minnesota soybean growers. The ZFN and TALEN mutagenesis approach promises to increase the efficiency of soybean genetic improvement. This approach would be useful for efficiently improving a variety of traits tailored to the needs of Minnesota soybean growers.

We will use genetic transformation to test which gene(s) confer IDC tolerance. Through this research, we will genetically transform gene-specific ZFN and TALEN proteins that will mutagenize soybean genes of interest and recover non-transgenic mutants with improved traits of interest.

We are targeting genetic transformation for IDC tolerance, nodulation processes and a wide range of gene-specific mutants. We have successfully transformed and continue to transform candidate genes for IDC and other advantageous traits of soybean root biology. We have demonstrated that soybean ZFN site-directed mutants are stable and heritable. The development of the IDC transformation and ZFN mutagenesis technology, along with advances in our understanding of the soybean genome and transcriptome will enable future projects that continue to accelerate the development of genetically improved soybean lines for Minnesota growers. Work from previous years of MSR&PC support for this project have been published in high-profile journals and have been presented in numerous national and international meetings.

+ Northwest Minnesota Soybean Research and Tech Transfer Proposal 2012-2013

podcast iconResearchers: Doug Holen, Howard Person, Phil Glogoza, Jodi Dejong-Hughes, Ben Arlt, Jeff Coulter, Dan Kaiser, Dean Malvick
Budget: $132,714

This research will seek expanded research partnerships with soybean grower involvement, participation and ownership in research communications. We will be expanding soybean applied research trials in cooperation with county soybean associations (six locations proposed) including foliar fungicides, micro-nutrients and MicroEssentials SZ (MESZ) each at two locations. Local research needs identified by producers will be addressed. We are hoping to build on collaboration efforts between local soybean associations, such as the Northern Soybean Growers Team, the MN Wheat Council and the U of M. Other potential collaborators include private consultants, researchers, the ND Soybean Council and NDSU researchers and extension.

We will look at on-farm evaluation of four tillage systems in a corn-soybean rotation. We will evaluate the long-term effects of four tillage management systems on corn and soybean yield, economic return, soil quality, soil temperature and residue cover.

Managing soybean aphid in an organic production system, we would like to evaluate alternatives for soybean aphid management in organic systems: adapting “speed scouting” for aphid treatment decisions in organic soybeans; continue to evaluate PyGanic (natural pyrethrum) performance at a lower action threshold; look at planting date and maturity group interaction; and look at insecticidal soap as an aphid population suppressant.

We want to evaluate soybean cyst nematode levels in northwestern MN to assess SCN infestation levels on a broader scale with field level. Surveys for SCN have been valuable at the county level for documenting expansion of the pest’s range. The program has been successful in raising grower awareness in the region. We would like to obtain more field level data from growers.

We will continue looking at soybean cyst nematode variety trials and assess SCN resistant soybean varieties in northwestern MN. In cooperation with the UMN Soybean Breeding program, three variety trial sites in northwestern MN will be established: Wilkin, Mahnomen and Red Lake counties.

Through this research, we will evaluate commercially available fungicides for management of white mold in soybean. We will establish plots in cooperators’ fields that have had white mold concerns in previous seasons. Fungicide products will include Topsin, Proline, Endura and Cobra (herbicide). Others will be considered, but emphasis will be on registered products.

+ Improving the Profitability of Soybeans in Southern Minnesota — Take Control

podcast iconResearchers: Lisa Behnken, Fritz Breitenbach, Ryan Miller, Lizabeth Stahl, David Nicolai
Budget: $80,000

This proposal is a continuation and expansion of the 2011-2012 project submitted by University of Minnesota Extension in southeastern, south central and southwestern Minnesota. Involvement of University personnel will occur at the county, regional and state level. Depending on the study, research will be conducted at on-farm locations and University research sites in southern MN and/or the University Research and Outreach Centers at Waseca and Lamberton.

We will continue our comparison of glyphosate, glufosinate and conventional herbicide programs. We will promote the “Take Control” theme, demonstrating the benefits of pre/post systems for improving efficacy of difficult-to-control weeds and for preventing and managing herbicide resistant weeds such as giant ragweed and waterhemp.

The development of resistant weed populations and/or reductions in weed control with a glyphosate-only system is causing concern and frustration. Use of pre herbicides can lead to improved weed control, increased yield and profits. Utilizing pre herbicides is also a key tactic in resistant-weed prevention and management. Growers, however, have shown a reluctance to include a pre herbicide in their weed control programs. This project will be implemented to help demonstrate the value of including a pre herbicide in weed management systems through on-farm research and demonstration trials. Replicated trials would be established at multiple locations across southern MN.

We will develop educational materials and programming on the results of two years of intensive on-farm trials to detect and manage the presence of soybean cyst nematode biotypes virulent on resistant varieties. We will prepare publications, posters, web-based videos, podcasts, etc. to tell the story and develop the “Take Control” theme. We will work to increase awareness of producers and their advisors about the difficulties associated with managing SCN resistance and increase adoption of sound management practices.

We will evaluate the impact of short season soybean after peas on soybean cyst nematode, SCN management, sulfur and micronutrient fertilizers on soybeans and soybean aphids, as well as late season control in R5 and R6 soybeans. We will continue our research to better understand SCN dynamics, Liberty Link soybeans, food grade value added soybeans and Roundup Ready soybeans.

+ Regulation of Seed Composition—Year Two

podcast iconResearchers: Sue Gibson, Jim Orf
Budget: $30,000

Seed composition is one of the most important determinants of the economic value of seed crops. Despite the importance of this trait, little is known about the molecular mechanisms responsible for controlling seed composition. In particular, genes involved in regulating seed composition remain to be identified. The goal of this proposal is to identify such genes in the model plant Arabidopsis and to then use those genes to develop improved varieties of soybeans. Previous research in our lab resulted in the tentative identification of six genes regulating seed composition. The primary goal of this proposal is to further test these genes to confirm or disprove their roles in regulating seed composition. Those genes that are found to have the most profound effects on these traits will then be tested in soybeans to determine whether they play similar roles and can be used to develop new soybean varieties with improved seed composition. We will seek to identify Arabidopsis homozygous for independent mutations in genes that affect seed protein content. We will analyze seed protein levels in mutants identified via the objective stated above. We will analyze seed lipid content and yield in protein content mutants. We will identify and characterize potential homologs of the most interesting genes identified above in soybeans. We will develop molecular markers to facilitate marker-assisted breeding programs. We will initiate experiments to test the effects of altering expression of the most interesting genes aforementioned in Arabidopsis and soybeans. The expected outcomes for this project are molecular markers that will be used over the next approximately five years to enhance and accelerate development of new soybean varieties with improved seed composition via traditional breeding approaches. Another expected outcome is the availability of genes that could be used in molecular breeding (GMO) approaches to improve soybean composition. The results of this project will be published in widely available journals. Increased knowledge about the genes that control seed composition will aid other soybean researchers interested in developing soybean varieties with altered composition. Thus, the results of this project will benefit research being carried out by other research groups and will help lead to varieties for Minnesota growers with improved composition.

Research Articles

+ Researchers Seek Strategies to Improve Soybean Quality

Key Points

  • Researchers are identifying promising seed protein and oil genes in soybeans and in Arabidopsis thaliana, a relative of soybeans with a simpler genome
  • In the last year, seven fast neutron lines were selected for stable differences in seed protein and oil composition

Improving soybean seed quality, both protein and oil, is a primary long-term objective of the University of Minnesota’s soybean breeding program. Three Minnesota Soybean Research & Promotion Council (MSR&PC)-funded research projects in 2012 focused on seed composition and controlling soybean seed quality through genetics and environmental control.

Improving seed composition qualities is a complex process involving oil, protein, amino acid and fatty acid components. “We emphasize protein a bit more than oil, but we work to get a good balance of both in the varieties we release,” says Jim Orf, University of Minnesota soybean breeder. “We have improved protein levels modestly, but there is a negative association between yield and protein content so we are always juggling that relationship. We need to find those exceptional varieties which have high yield and modest improvements in protein.”

Finding Key Genes

To get a better handle on what genes control seed composition, U of M researchers are employing molecular genetic tools. Sue Gibson, associate professor in the College of Biological Sciences has identified six promising genes that may control seed yield and composition in Arabidopsis thaliana, a plant that produces oilseeds similar to soybean, but has a much simpler genome. These genes will be used to identify similar genes in soybeans and develop molecular markers to facilitate marker-assisted breeding programs. “At one point, these plants had a common ancestor, so the DNA sequences are similar,” notes Gibson. Six candidate genes from soybeans have also been identified and will be transformed into transgenic soybean plants that will be grown and evaluated in greenhouses in 2013 and 2014.

On a related front, Bob Stupar, assistant professor in the Department of Agronomy and Plant Genetics, has worked with USDA researcher Carroll Vance to use high-throughput next generation DNA sequencing of two well-characterized soybean parent lines, Minsoy and Noir 1, to identify genes with contrasting seed protein and oil levels. Stupar has developed molecular markers for two genes involved with increased oilseed production and those genes will be transformed into soybean lines for further study.

His team has also worked with Vance, Orf and U of M research agronomist Seth Naeve to create new genetic diversity using a process whereby seeds are blasted with fast neutron particles to create novel deletions and duplication of genes in the seed. “We are making progress in understanding and utilizing the fast neutron materials in the breeding program,” says Stupar. In the past two years, seven fast neutron soybean mutant lines were selected for stable differences in seed protein and oil composition. Some of the mutant lines showed close to a 15 percent increase in seed protein or a 30 percent increase in seed oil, along with increased total seed protein and oil content. The next step is to incorporate these genes into soybean breeding lines.

Environmental Differences

In addition to finding genes that affect seed composition, some research projects are focused on discovering the environmental factors affecting protein and oil content. A cooperative project funded by the United Soybean Board (USB) and MSR&PC includes studies to evaluate the effect of waterlogged and drought-prone soils on seed protein concentrations, determine environmental factors affecting amino acid balance of soybeans and use six years of soybean quality data to model environmental impacts on soybean composition.

“We weren’t able to get good data about performance in waterlogged soils this past year, but we did learn that late season drought tends to greatly reduce the oil content of the seed,” says Naeve. “Late season drought had little effect on protein levels, which means that protein accumulation in the vegetative part of the plant early in the season is really important for maintaining yields later in the season.” More data will be gathered in 2013.

“The soybean seed is composed primarily of protein and oil. We want to understand how the environment, production methods and genetics affect protein and oil separately. Then we can get a better understanding of how it drives yields,” he says. “Ultimately, we want to increase the value of soybeans for Minnesota farmers. Farmers aren’t paid directly for quality, but there is a discount built into the price for soybeans exported from Minnesota because of the lower crude protein content.”

Earlier checkoff-funded research has established that soybeans grown in more northerly areas don’t have as high of protein content as soybeans grown in southern areas of the U.S. However, further checkoff-funded research has shown that soybeans with lower crude protein values, such as those produced in the northern United States, contain higher concentrations of critical essential amino acids and will therefore produce a higher quality feed ingredient.

Orf notes that another U of M project is comparing the oil and protein content of South American soybeans with Minnesota soybeans. “We need to know what our competitors’ products are like so we can be a step ahead in our breeding efforts and ensure that our soybeans have the best quality for domestic and international users.”

+ Genome-Wide Selection Seeks Combination of Best Soybean Traits

Key Points

  • Combining bioinformatics and robotics with insights from the soybean genome sequence allows researcher to analyze several thousands of DNA markers at a time
  • Researchers hope to determine which combination of DNA markers is predictive of the best combination of soybean traits

Genetic improvement is a numbers game. The more genetic combinations that can be tested, the faster soybean varietal improvements will reach farmers. With approximately 50,000 genes and each gene having thousands of base pairs, the potential genetic combinations become mind-boggling.

“Just a few years ago, soybean breeders could only analyze a few dozen DNA markers. Combining bioinformatics and robotics with insights from the soybean genome sequence, we can now easily analyze several thousands of DNA markers at a time,” says Nevin Young, professor in the University of Minnesota Department of Plant Pathology.

New advancements in molecular analysis combined with increased computing strength are giving soybean breeders more power to develop varieties with the best combination of traits.

That’s the focus of the U of M’s genome-wide selection project, which takes a more holistic view of the soybean genome. “We’ve taken the DNA marker strategy and magnified it so instead of looking at one or two genes, we look at several hundred genes and then we pick the most favorable combinations based on data from the field and the laboratory,” says Young. “We have some really smart people in genetics and mathematics working on this. I believe genome-wide selection will impact the kinds of selections breeders make within two to three years. It won’t replace conventional breeding; it’s just another set of data points to make the best choices.”

Breeder Jim Orf agrees, “With bigger and better computers, we are able to analyze and relate the data from thousands of plants in the field to the actual genetics of the soybean. Having the soybean genome sequenced gives us an opportunity to determine which genes are present and link that sequence with our data on yield, protein, oil and resistance traits. Then we can look for genes that are more positive in improving these traits. That means we can do a better job of selecting plants for evaluation that we know maximize positive attributes while minimizing negative attributes.”

The goal is to determine which combination of DNA markers is predictive of the best combination of soybean traits. “We are optimistic that genome-wide selection will help us make faster progress in improving soybean varieties,” says Orf.

+ Ways to Limit Resistant Nematode Populations

Key Points

  • When nematode populations are high, it takes five years of a non-host crop to reduce them to low levels
  • Beyond rotation, nematode populations can be suppressed by planting resistant soybean varieties
  • If SCN populations are low or non-existent, farmers should not plant a SCN-resistant variety as it could speed the development of resistant nematodes.
  • Farmers should determine SCN populations, then HG types to match the correct resistant variety to conditions in the field (BOLD)

Most SCN-resistant soybean varieties in the United States are derived from PI 88788 or the Peking parent lines. As SCN populations change to overcome the resistance sourced from these parent lines, growers need to employ resistance management strategies.

“After two decades of use, we have an urgent problem in the Midwest. More than 70 percent of fields have populations of nematodes that have evolved to reproduce on PI 88788 derived varieties. PI 88788 resistance is no longer effective in 20 percent of fields,” says Senyu Chen, professor of plant pathology.

This change in virulence phenotypes occurs in fields where resistant varieties have been planted repeatedly for a number of years. Today, we use HG types, to describe the different populations of nematodes and their ability to reproduce on specific resistant lines. In Minnesota, nematode populations are becoming more virulent, in particular for PI 88788, PI 209332, PI 548316 and Peking resistance sources.

Match Soybean Variety to Your Field Conditions
Once you have nematodes, they don’t go away easily. When nematode populations are high, it takes five years of a non-host crop to reduce them to low levels. Beyond rotation, nematode populations can be suppressed by planting resistant soybeans.

However, if SCN populations are low or non-existent, farmers should not plant a SCN-resistant variety as it could speed the development of resistant nematodes. “We need to get this message out to farmers because many ag professionals promote using resistant varieties as insurance, but this is not a good practice,” says Chen.

Ideally, farmers should determine SCN populations first, then HG types to match the correct resistant variety to the conditions in the field. Many resistant varieties have the same parent, so rotation of resistant varieties alone may not be sufficient to avoid resistance problems.

Chen says, “If you have poor yields and have been planting the same resistance source for more than five years, it is recommended to have the HG type evaluated.”

In addition to testing and evaluating soybean germplasm and varieties for SCN resistance, Chen researches other management strategies. “We’ve done a lot of field studies to look at cultural management, fertility, crop rotations and tillage. What we discovered is that management practices that improve soybean growth ultimately improve the plants’ tolerance to nematode damage,” he says.

+ New Asian Parasitic Wasps Help Keep Aphids in Check

Key Points

  • The U of M received a permit in October, 2012 to release a parasitoid wasp species called Aphelinus glycinis that specializes in feeding on soybean and cotton aphids
  • Another Asian soybean aphid parasitoid from the same genus, Aphelinus certus was discovered throughout soybean growing areas in Minnesota in 2012 and will likely help suppress soybean aphids
  • Pairing biological controls, like wasps, with resistant varieties and insecticide treatments when economic thresholds occur increases the durability of the aphid IPM program (BOLD)

Nature’s ability to overcome resistance is one reason researchers are looking at a broad array of tactics to control aphids, which arrived in North America in 2000 from Asia. Biological control is an important component of a durable integrated pest management strategy.

George Heimpel, professor of entomology at the University of Minnesota, was a part of research team that went to China in 2001 to study the natural enemies of soybean aphids. “We found soybean aphid populations were at very low levels in China compared to levels in the U.S. It turned out that a high rate of parasitism by tiny stingless wasps was controlling aphids in China. The wasps lay their eggs in the aphids, eventually killing them,” explains Heimpel.

The absence of those wasps in the U.S. allowed aphids to flourish here and become a major pest. “We wondered whether we could bring one or more of these Asian wasp species here to attack soybean aphids and reestablish the ecological balance that is present in Asia. This classical biological control approach has been successful with other insects,” he says.

Eventually, Heimpel and his UDSA colleague in Delaware brought back various species of parasitic wasps to study in quarantined laboratories. They screened and assessed the ecological safety of nearly 30 different Asian parasitic wasps. “These wasps only attack aphids, but we wanted to know if they attacked one aphid species or many aphid species. If they attacked a lot of aphid species, it could lead to ecological risks if they were released here,” he says. “We were able to conduct this work in Minnesota because we have a level 2 quarantine lab on the St. Paul campus.”

The Minnesota Soybean Research & Promotion Council (MSR&PC) as well as the North Central Soybean Research Program has been funding Heimpel’s research on the parasitic wasps.

The researchers discovered that about half the parasitoids were specialists that fed primarily on soybean aphids and the other half were generalists that fed on a lot of different types of aphids. The next step was to apply for USDA release permits for some of the specialist wasps.

Two Wasp Species Released in Minnesota
Binodoxys communis was the first species approved for field testing in 2007, but was not successfully established in Minnesota. The U of M was issued a second permit in October 2012 for a newly identified parasitoid wasp species called Aphelinus glycinis that specializes in feeding on soybean and cotton aphids. A. glycinis was released into buckthorn sites this past fall with plans to release into soybean fields in the summer of 2013. “This is a major development for soybean aphid biological control and we’re excited about its potential,” says Heimpel. “We think this species will be able to overwinter in Minnesota.”

Another Asian soybean aphid parasitoid from the same genus, Aphelinus certus was discovered throughout soybean growing areas in Minnesota in 2012. “This is an important development since this species is currently being credited with suppressing soybean aphids in Ontario and Quebec,” says Heimpel. “This wasp came here accidently from Asia, just like the soybean aphid did. It was not intentionally released in North America because it attacks many different types of aphids. Now, Minnesota has two wasp species that can help us control soybean aphids.

Wasps Increase Durability of Aphid Control
“A great thing about parasitoids is there is no risk of the soybean aphid developing resistance. It’s part of a sustainable, long-term solution to controlling soybean aphids.”

Pairing biological controls, like the wasps, with resistant varieties and insecticide treatments when economic thresholds occur increases the durability of the aphid IPM program. “These wasps are better at keeping aphid densities low rather than driving down high populations so they work best in concert with other controls. For example, resistant soybean varieties lower aphid densities enabling natural enemies to finish the aphids off,” says Heimpel.

If aphids reach the economic threshold in a field, farmers should treat the field with an insecticide. “If growers abide by the threshold, there will be enough fields that stay unsprayed so the parasitoids won’t be at risk of being snuffed out,” Heimpel says. It’s extremely important to not spray before economic threshold are reached in order to maintain the viability of the IPM system.

In the last few years, aphid populations have been significantly lower. That could be due in part to more natural predators of soybean aphid. “The community of predators takes a while to build up when there is a new food source. There has been a ramping up of the naturally occurring biological control of soybean aphids over last 10 years,” says Heimpel. These predators include ladybugs and native parasitic wasps. Even so, soybean aphid is still an economic pest. “These native predators will help keep the aphid baseline population at manageable levels so the new Asian parasitoid wasps can do their part,” he says. “They all work together.”

+ Potential New Way to Screen for Iron Deficiency Chlorosis Tolerance

Key Points

  • If seed iron concentration is predictive of resistance to IDC, then it could provide a more rapid breeding selection method
  • Target ortho-ortho iron chelate applications to areas where IDC is moderate to severe for best economic return

Minnesota checkoff funded research projects in the last year looked at ways to better manage iron deficiency chlorosis (IDC) in soybeans, as well as potential new methods to screen varieties for tolerance. IDC is not caused by a lack of iron in the soil, but by an inability of the plant to take it up. An important production hazard in western and northwestern Minnesota, IDC is associated with high pH soils that make iron less available to the plant.

An ongoing research project is evaluating whether seed iron concentration is predictive of tolerance to IDC. In 2011, researcher John Wiersma at the Northwest Research and Outreach Center, Crookston, observed that higher concentrations of iron in the seed correlated with better tolerance to IDC in a study of 23 varieties. In 2012, in collaboration with soybean breeder Jim Orf, the study was expanded to 70 lines grown in both Crookston and Rosemount. Researchers found a moderate correlation and will continue studying the effect in 2013.

In 2013, Jim Kurle, associate professor of plant pathology, will also look at how iron is mobilized in the seed coat to the cotyledon through the germination period. “It could be that the iron in the seed is enhancing early plant growth,” speculates Kurle.

The primary management tool for IDC is planting IDC tolerant varieties. If seed iron concentration is predictive of resistance to IDC, then it would provide a more rapid breeding selection method. Measuring iron in the seed is easier than evaluating IDC tolerance in field nurseries, which are dependent upon environmental factors. Another part of the project will investigate whether molecular markers associated with seed iron concentration can be used in breeding programs.

IDC Management Options Studied
Dan Kaiser, U of M Extension nutrient management specialist, just completed a three-year study that looked at two techniques to manage IDC: seed placement of an ortho-ortho iron chelate such as Soygreen or interseeding oats.

The Soygreen treatment in the study provided a 5-8 bu./ac. average yield advantage where there was moderate to severe IDC. In severe cases, it provided a yield advantage of up to 20 bu./ac. “At three pounds of active ingredient per acre, the cost is $25 to $30 per acre. It’s expensive, so the best approach is to target its use where IDC is moderate to severe,” he says.

Interseeding is an option for growers who don’t have in-furrow starter fertilizer equipment, but it comes with higher risk. Planting a companion crop with soybeans helps by taking up excess soil nitrate, which has been shown to increase the severity of IDC. During the three-year study, interseeding oats before planting resulted in a 3-5 bu./ac. yield increase in areas with severe IDC. “Letting the oats grow too long is risky. Significant yield reductions have occurred where the oats were left to grow more than 10 inches,” says Kaiser. “Terminating the oats too early does not allow for adequate uptake of nitrate.”

+ Tile Drainage Improves Soybean Yields

Key Points

  • In 2011, soybean yields were 17 percent higher in drained plots than undrained plots near Fargo, N.D.
  • In 2012, a much drier year, yields were not statistically different and there was no negative effect to having tile in a dry year in trials in Fargo and in Lamberton, Minn.

A joint Minnesota and North Dakota checkoff funded tile drainage research project conducted by North Dakota State University professor Hans Kandel near Fargo found that soybean yields were 17 percent higher in drained plots than undrained plots in 2011. In 2012, a much drier year, yields were not statistically different, and there was no negative effect to having tile in a dry year. Kandel also observed less iron deficiency chlorosis in the drained areas and found that root growth is better in drained soils.

While many farmers know the benefits of tile drainage, the benefits are often not understood by those outside of agriculture. Unbiased research can quantify some of these advantages.

MSR&PC is funding further tile drainage research with University of Minnesota researchers Seth Naeve, Jeff Coulter and Gary Sands. In 2011, the U of M established a site near Minnesota Lake on a poorly drained field. The 17-acre field was pattern tiled (30’ apart) into eight distinct blocks of tile that can be managed independently with a valve to make undrained and fully drained blocks in the field.

The results from 2012, a drought year, resulted in no benefit to drainage and no interaction between drainage and various high input treatments. There was no reduction in yield by having the tile despite late season drought conditions. This is consistent with other field observations in the Midwest. Long-term research studies will be established in 2013 at this site.

+ Applied Research and Tech Transfer Projects

The Minnesota Soybean Research & Promotion Council (MSR&PC) funds two large, regionally applied research and education projects that encompass many field studies in northwest and southern Minnesota.

Key Points

  • U of M county yield trials are available through county extension offices or through this link: varietyplot.mncorn.org/
  • In northwestern Minnesota, 2012 studies included on-farm tillage comparisons, SCN monitoring, aphid management in organic systems and population trials
  • In southern Minnesota 2012 studies focused on weed control and weed resistance management, SCN management, aphid management, and micronutrient trials
  • A new SCN project called the “ten versus ten trial” will determine whether planting non-resistant varieties on fields with low or non-detectable levels of SCN is a viable option in southern Minnesota

Northwest Minnesota Soybean Research and Tech Transfer
“We give farmers timely, unbiased data about current production concerns and come up with conclusions that can be immediately incorporated into their cropping system,” explains U of M researcher Doug Holen, who coordinated research team members including Jodi DeJong-Hughes and Phil Glogoza for projects in northwest Minnesota.

2012 studies included on-farm tillage comparisons, soybean aphid management in organic systems, soybean cyst nematode monitoring and soybean variety trials. Following are the research highlights.

Tillage
Tillage studies conducted over a three-year period showed that high residue systems, such as strip till and no-till, had no significant impact on plant population and yield in corn and soybeans the following year, and costs per acre were reduced with fewer tillage passes.

Aphid Control
After looking at various organic aphid control options, the researchers found that natural pyrethrum worked best but provided suppression of only 50-60 percent of aphids. In outbreak years, multiple applications will be needed. It was also determined that the economic threshold for the organic system is 100 aphids per plant instead of the 250 aphids per plant with conventional insecticides.

SCN
During soybean field days in August, sample kits and instructions for collecting soybean cyst nematode (SCN) soil samples were provided to growers. Multiple counties in northwestern Minnesota had at least one positive SCN sample identified. “Producers need to recognize SCN is all over the Red River Valley and they need to proactively manage it so it doesn’t go off the charts,” says Holen. Variety trials were conducted at four locations to assess SCN resistant soybean varieties.

Plant Populations
A soybean planting population trial conducted at seven locations in northwestern Minnesota in 15-in. rows found that soybean yields increased significantly when doubling plant populations from 75,000 ppa to 150,000 ppa. There was no statistically significant yield enhancement going from 150,000 to 200,000 ppa. However, the maximum return ($668 per acre) was obtained with the 175,000 ppa seeding rate. Protein and oil content was not affected by planting rates.

Southern Minnesota Soybean Research and Tech Transfer
“Our project is focused on improving the profitability of soybeans in southern Minnesota,” says U of M Extension Educator Lisa Behnken, who coordinates the projects in southern and southeastern Minnesota with Fritz Breitenbach, Ryan Miller, Lizabeth Stahl and David Nicolai.

2012 studies focused on weed control and resistance management, soybean cyst nematode management, aphid management, micronutrients and variety trials. The following are research highlights from two key trials.

Pre/Post vs. Post Only Herbicide Programs
Before glyphosate-resistant varieties, farmers used a pre-emergence herbicide on 60-70 percent of soybean acres in Minnesota. With the introduction of Roundup Ready soybeans in 1996, growers began using a timely, one pass, post-emergence application. In 2010, 71 percent of growers relied on a complete post-herbicide program for their soybeans. In 2012, this dropped to 55 percent, with about half of southern Minnesota growers indicating they have resistant weeds on their farms.

“Weed resistance has moved from a concern to a reality,” says Behnken. “Weeds steal yield. We must take control and preserve the technologies available to us. That means growers must focus on herbicide systems and develop long-range plans for their farms.”

Southern Minnesota research trials and on-farm herbicide trials have demonstrated the value of pre/post herbicide programs. “Sequential pre/post herbicide programs provide the best weed control and perform better than tank mix treatments with glyphosate,” says Behnken. Research showed that a pre-emergence herbicide reduces weed density, weed species and weed size by the time of post-emergence application. It also increases yield potential, weed control, early season canopy and herbicide/adjuvant compatibility.

In an exciting development, the U of M secured a piece of ground near Rochester that has known glyphosate-resistant giant ragweed, which will be a huge asset as it conducts future herbicide trials and evaluates new chemistries.

Managing SCN biotypes
The southern research team has conducted two years of on-farm trials aimed at detecting and managing SCN biotypes that are virulent on resistant soybean varieties. They will be developing educational materials and programs to increase awareness among producers and increase the adoption of sound management practices. In addition to the on-farm trials, the team continues to conduct research trials evaluating new SCN resistant varieties, and new biological and chemical seed treatments for the purpose of managing SCN.

In 2012, a new SCN project called the “ten versus ten trial” was initiated. The concept is to test ten top-yielding resistant varieties and ten top-yielding non-resistant varieties in hopes of showing that planting non-resistant soybean varieties on fields with low or non-detectable levels of SCN is a viable option. Planting non-resistant varieties is a critical component of SCN resistance management because continually planting the same resistant varieties will create populations of SCN that are virulent on those resistant soybean varieties, rendering the resistant soybean varieties useless. (For more information see related article in the digital annual report.)

County Soybean Variety Trials
Picking the right variety is the number one thing growers can do to improve yields and return on investment. Both the northwest and southern Minnesota tech transfer projects include extensive variety trials throughout the state. U of M county variety trial results are available through county extension offices or through this link: varietyplot.mncorn.org/