2021
Red crown rot distribution and seed treatment efficacy in Illinois - year 2
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Contributor/Checkoff:
Illinois Soybean Association
Category:
Sustainable Production
Keywords:
Crop protectionDiseaseField management
Parent Project:
Gathering information on red crown rot distribution and seed treatment efficacy in Illinois
Lead Principal Investigator:
Nathan Kleczewski, University of Illinois at Urbana-Champaign
Co-Principal Investigators:
Project Code:
Contributing Organization (Checkoff):
Illinois Soybean Association
$47,178
Institution Funded:
University of Illinois at Urbana-Champaign
$47,178
Brief Project Summary:

Red crown rot is a soilborne fungal disease new to Illinois. Affected plants senesce prematurely and often contain characteristic red, ball-like structures on the lower stem and crown, which contain spores of the fungus. In this second year of the project, researchers will replicate work and expand the ability to detect the pathogen. Particular objectives include: surveying Illinois soybeans for RCR to determine distribution and potential acreage affected; screening multiple, commercially available soybean fungicide seed treatments for utility in managing RCR and protecting yield; and developing a RCR-specific molecular tool to aid in future management.

Key Benefactors:
farmers, plant pathologists, agronomists, extension specialists

Information And Results
Project Deliverables

Proposed Methods/Tactics



Fields with interveinal chlorosis starting at the reproductive stage in growth will be targeted for sampling. Plant samples will be acquired at R5/R6 from each field, and sent to the Kleczewski lab, where they will be processed for presence of the pathogen following established protocols. A second season of the survey will be beneficial, as environmental conditions can mask disease symptoms from year to year, and fields infested with the pathogen may not be planted to soybeans during the first season.

Soybean seed treatments to screen for efficacy against RCR again in year 2, to increase the robustness of the data and account for environmental impacts on disease in field trials. Screening will occur in the greenhouse and microplots to assess their ability to reduce seedling blight and plant growth, and reduce foliar symptoms. A larger scale on farm study for will be conducted at a field in Pittsfield where the disease is established, allowing us to obtain yields and inoculate the site. All trials will be replicated and randomized, and data statistically analyzed.


The RCR pathogen, Calonectria ilicicola is a fungus with a broad host range and typically is found in warm regions where peanuts are produced in rotation with soybeans. Calonectria spp. are also important pathogens of ornamental legumes and trees (e.g. boxwood blight). Previous studies have used the internal transcribed region to generate species specific primers for detection of other speciesw of Calonectria on eucalyptus, and avocado [16] and due to the widespread capacity for members of the genus to cause disease on economically important legumes, online databases such as GenBank contain an abundance of Calonectria sequence data. Consequently, we can utilize sequence data from our isolates, vouchers from the USDA Mycology collection housed in Peoria, IL and online sources to develop a set of species-specific primers for use in detecting and quantifying C. ilicicola from plant tissues and soils. We will first focus on the internal transcribed region of the ribosomal DNA (rDNA) subunit, as this has been used in previous work to detect specific members of the genus. Primer sets will be designed using online primer design tools, and tested against a set of Calonectria DNA acquired via the USDA mycology collection, UIUC herbarium, and samples acquired from colleagues in other states and regions for specificity. The method will be tested on both infected plants and Calonectria-amended soil to confirm its utility, and sent to colleagues for confirmation.

Timeline:

Quarter One activities: Begin planning 2021 field season. Request seed and chemical treatments. Request Calonectria vouchers.

Quarter Two activities: Receive materials for field season. Plan field season layout. Start greenhouse trial. Start tool development.

Quarter Three activities: Plant field experiments and microplots. Rate trials. Test tool. Present study and preliminary data at field days

Quarter Four activities: Maintain field experiments. Collect data. organize survey (year 1).


Final Project Results

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.