Develop and deliver best management practices and soybean cultivars to minimize yield and quality losses from Cercospora leaf blight
Sustainable Production
AgricultureCrop protectionDiseaseField management Sustainability
Parent Project:
This is the first year of this project.
Lead Principal Investigator:
David Moseley, Louisiana State University AgCenter
Co-Principal Investigators:
Project Code:
Contributing Organization (Checkoff):
Institution Funded:
Brief Project Summary:
The proposed research will develop an integrated pest management approach to help reduce profit losses due to CLB. Locations where fungicide resistance has occurred, and the efficacy of fungicides will be communicated. Finally, commercial cultivars and elite germplasm with documented resistance to CLB will be released to help mitigate continued pressure on fungicide chemistries.
Information And Results
Project Summary

Project Objectives

Project Deliverables

Progress Of Work

Final Project Results

Key Deliverable 1: Discover genetic resources to CLB and integrate into elite germplasm The University of Missouri released S18-6013C in 2023 as a high yielding and high oil cultivar. It is a semi-determinate early group V [relative maturity (RM) 5.2] soybean cultivar. It was tested across eight states in 42 environments, it yielded 117.5% of the non-Xtend check mean and 103.2% of the Xtend check mean. It averaged 19.6% oil, 35.1% protein, and 47.4% meal protein at 13% moisture. Seeds of S18-6013C have been submitted to the Missouri foundation seed program for production. In 2023, The University of Missouri also released S19-19923HOLL, a high yielding, high oleic acid, low linolenic acid soybean cultivar derived from CLB resistant parent. It is an early group V maturity (relative maturity 5.2), determinate soybean cultivar. It yielded 99.7% of the non-Xtend check mean, 90.6% of the Xtend check mean across 33 environments. It averaged 79.6% oleic acid and 2.2% linolenic acid. It was in the Uniform Group V early test. Key Deliverable 2: Determine fungicide efficacy at diverse field locations and develop an internet-based fungicide resistance distribution map. The LSU AgCenter has optimized Loop-mediated isothermal amplification (LAMP) assay to identify QoI resistance in CLB pathogens. In 2023, The LSU AgCenter has collected CLB isolates from multiple counties/parishes from Arkansas, Mississippi, and Louisiana. Some lab work is currently in progress, but the approximate number of isolates per state are: Louisiana - 184 Isolates - Collected from Four Parishes Arkansas - 53 Isolates - Collected from Two Counties Mississippi - 50 Isolates - Collected from Two Counties The University of Arkansas identified a total of 50 Cercospora isolates, out of which 62% are C. flagellaris, 32% C. kikuchii and 6% are C. sojina. Identified Cercospora spp. were isolated from mainly soybean seed collected from Arkansas, Indiana, Ohio and Michigan. An additional 30 to 50 isolates, that are currently being cultured or stored, will be sequenced and added to the current collection. Furthermore, an in vitro assay will be conducted to evaluate sensitivity of the 50 identified Cercospora isolates to a QoI (Azoxystrobin) and DMI (Tetraconazole) fungicides at different concentrations. A website to display CLB research information has been set up and approved by the United Soybean Board. This website will include a CLB distribution map. Key Deliverable 3: Evaluate the efficacy and profitability of fungicides to CLB and develop application protocols. Rachael Wolf, a MS student from the University of Arkansas, has completed her thesis on the development of a detached leaf assay for cultivar resistance to target spot, caused by Corynespora cassiicola. She used her method to evaluate soybean lines from the 2019 and 2020 Cercospora Leaf Blight region study for target spot resistance. A paper on her results will be submitted in the near future. The University of Arkansas related seed infection by Diaporthe longicolla, Cercospora species, and total seed infection, as well as visible seed damage to 46 seed constituents measured by NIR of seed from five Cercospora Leaf Blight cultivar tests conducted in 2019, 2020 and 2021 in Arkansas. Stepwise regression was used develop multiple regression equations with combinations of seed factors that significantly related seed composition to each of the seed infection parameters. The University of Arkansas is currently exploring methods for presenting thier results and then will write a paper on the results. The LSU AgCenter presented information regarding fungicide efficacy against CLB at parish production meetings in 2023.

Benefit To Soybean Farmers

1. New sources of high yielding soybean varieties that have resistance to Cercospora leaf blight (CLB) will allow farmers to grow soybean in areas that have high incidence of CLB. This is especially important in areas that CLB has resistance to fungicides. 2. Developing data on the efficacy and profitability of fungicides to CLB can help farmers control CLB. 3. Identifying growing areas that have CLB resistant to fungicides will help growers know when to conduct other best management practices.

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.