2018
Disease Management Equals Higher Yields
Home
Contributor/Checkoff:
Ohio Soybean Council
Category:
Sustainable Production
Keywords:
Crop protectionDiseaseField management
Parent Project:
This is the first year of this project.
Lead Principal Investigator:
Anne Dorrance, The Ohio State University
Co-Principal Investigators:
Project Code:
18-R-05
Contributing Organization (Checkoff):
Ohio Soybean Council
$100,000
Institution Funded:
The Ohio State University
$100,000
Brief Project Summary:

Several soybean pathogens have re-emerged as yield robbers in Ohio, primarily due to very wet springs, resistance to fungicide seed treatment and varieties with low levels of resistance. This project aims to identify the best disease management practices for Ohio’s challenging environments and changing pathogen populations. The first goal is identifying resistance to the many pathogens that affect soybean and the markers and genes that define the region in the genome that contribute to trait expression. The second is to identify seed treatment and foliar fungicides with the greatest efficacy towards mitigating losses when disease does develop. The third is to monitor the changing pathogen populations including the adaptation to common fungicides.

Key Benefactors:
farmers, agronomists, extension agents, soybean breeders, seed companies

Information And Results
Final Project Results

Update:
1. This quarter, we screened 399 lines in 5 different populations for resistance (Rps genes, quantitative resistance or both to P. sojae and are now beginning new populations from the harvest this year.

2. We received only 8 samples of frogeye leaf spot from 6 counties during the summer of 2018 and more are still in process. All of the samples received had the marker for the most common mutation for resistance to strobilurin fungicides. These results will impact the recommendations for farmers in Ohio that have frogeye to focus on other fungicides with a different mode-of-action. A note to add to this, graduate student Linda Weber has done most of this work and we contributed our data to a regional paper led by Carl Bradley which was just accepted in Plant Health Progress.

3. A. We have had a back-up in the Molecular Cellular Imaging Center this summer and we are still analyzing the sequence data from the 161 isolates that were recovered from five locations in Ohio where we evaluated seed treatments. Additionally, DNA was collected from soil samples to assess diversity using a microbiome approach and this analysis is ongoing. These isolates will be used in these studies that assess genetic change within Ohio populations.

B. We are comparing the genetic region in P. sojae that controls the response on varieties that have Rps1a and Rps1c between isolates from Ohio and Iowa. Both populations have gone through pathotyping and aggressiveness. The amplicons of this region in each of the isolates was submitted for sequencing, analysis and publication are in progress.

C. To date, all 950 soil samples from Ohio, Indiana, and Kentucky have been baited at least once. Currently, 538 isolates of Phytophthora sojae were recovered from 950 soil samples collected from Ohio, Indiana, and Kentucky- approximately 50% of the 538 isolates have been pathotyped to determine which and if any of the current Rps genes would be effective. Graduate student Linda Weber is on course to complete this by the end of December. Additionally, she has started genotypic diversity with the SSR markers.

4. Work on the manuscripts has been slow this summer for a variety of reasons and interruptions. We are also impatiently waiting for a post-doc to obtain the correct approvals to begin work. The list of the next candidate genes to go after is in place – we just need the people now. Four of the Nested Association Mapping populations which we mapped QDRL towards P. sojae and several Pythium spp. are in the field. Phytophthora stem rot developed on a few of the RILs in each population, we are anxiously awaiting yields from these trials.

5. Studies for new chemistries for seed treatments to control, Fusarium, Rhizoctonia and water molds (Pythium and Phytophthora); foliar fungicides for frogeye leaf spot; and flowering applications for Sclerotinia appear to be very successful this year. Studies are located in Four OARDC branches: North Central near Fremont, Western near south Charleston, Northwest in Wood County, and of course Wooster campus. Trials are also on farmers' fields in Erie, Paulding, Logan, and Clinton counties. Total number of plots for 2018 – 5979! Data was collected throughout the season and now we are waiting for yields!

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.