2012
Improved management of Sclerotinia stem rot in the North Central Region
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Contributor/Checkoff:
North Central Soybean Research Program
Category:
Sustainable Production
Keywords:
Crop protectionDiseaseField management
Parent Project:
Improved management of Sclerotinia stem rot in the North Central Region
Lead Principal Investigator:
Paul Esker, University of Wisconsin
Co-Principal Investigators:
Daren Mueller, Iowa State University
Martin Chilvers, Michigan State University
Kiersten Wise, Purdue University
Carl Bradley, University of Kentucky
Dean Malvick, University of Minnesota
Craig Grau, University of Wisconsin
+5 More
Project Code:
Contributing Organization (Checkoff):
North Central Soybean Research Program
(n/a)
Institution Funded:
University of Wisconsin
(n/a)
Brief Project Summary:

This project is designed to combine concepts of plant pathology and soybean breeding in an attempt to raise soybean yield potential and stability of soybean yield in the North Central Region. The specific goal of this project is to identify and understand the expression of resistance to Sclerotinia stem rot (SSR, white mold) that is of a high level and stable across multiple environments. A secondary goal is to improve coordination of SSR research in the North Central Region through coordinated and collaborative effects in breeding and integrated approaches to disease management and extension programming.

Unique Keywords:
#sclerotinia white mold, #soybean diseases
Information And Results
Project Deliverables

Final Project Results

reeding lines within five of eight populations (F8:9 generation) were characterized for reaction to Sclerotinia sclerotiorum in greenhouse trials. Trial one was a completion of 902 (F8:9 generation) lines initiated in the previous reporting period. A subset of 194 lines was reevaluated during this reporting period. Lines were rated on a scale of 0 (no infection) to 4 (plant mortality) at the R6 growth stage. Of the 194 lines, 138 lines expressed a disease severity score of 1 or less. Six lines expressed a rating of 0 and 51 expressed less than 10% plant mortality. The remaining lines are being further evaluated for resistance to white mold. Data from both trials were used to select lines for a preliminary search for genetic markers associated with resistance.

Two breeding lines from this current project were compared to commercial soybean varieties and standard checks for white mold studies. Greenhouse grown plants were inoculated at the R1 growth stage using a lower stem inoculation method. Commercial varieties were selected on the basis of superior yield in trials conducted by Shawn Conley, Department of Agronomy. Plant mortality for commercial varieties ranged from 56% to 86% compared to 3% and 18% for the two breeding lines.

The defining goal of this project is to identify genetic markers associated with resistance among lines within the eight breeding populations. Ninety breeding lines and six parental lines were selected for an initial trial to search for genetic markers associated with resistance to S. sclerotiorum. Seed of each line or parent was provided to Dr. Brian Diers, University of Illinois. Dr. Diers has planted seed and will isolate DNA from seedlings of each line or parent. DNA will be sent to Dr. Perry Cregan located at the USDA Beltsville Agricultural Research Center. Our project has provided Dr. Cregan with laboratory supplies to evaluate lines and parents for genetic markers related to resistance to S. sclerotiorum.

Extension activities during 2011 included the completion of the new White Mold Management Guide. This guide includes the following sections:
• Disease cycle;
• Signs and symptoms of white mold;
• Yield loss and seed infection;
• Cultural practices for white mold management;
• Genetics and variety selection;
• Chemical control;
• Biological control; and
• Core Recommendations (Putting it all together for white mold management).

Extension activities include the recording of seven white mold podcasts. The titles are:
• What is white mold?;
• Understanding the risk of white mold in a growing season;
• Biological control of white mold;
• Foliar fungicides for white mold;
• Estimating yield loss due to white mold;
• Impact of irrigation on white mold; and
• Guidelines for an overall management plan to reduce white mold.

These podcasts have been created into “enhanced podcasts” and will be made available in spring 2012. We also submitted a Journal of Integrated Pest Management (JIPM) article, which is an expansion of the extension publication that was produced earlier. JIPM articles are geared towards extension specialists and agriculture practitioners.

The United Soybean Research Retention policy will display final reports with the project once completed but working files will be purged after three years. And financial information after seven years. All pertinent information is in the final report or if you want more information, please contact the project lead at your state soybean organization or principal investigator listed on the project.