Project Details - Full Facts for Selected Year

Parent Project: This is the first year of this project.
Checkoff Organization:Kansas Soybean Commission
Categories:Soybean diseases
Project Title (This Year):Soybean production systems to control charcoal rot and other soilborne diseases
NCSRP, USB, QSSB Project Code:1773
Project Year:2017
Lead Principal Investigator:Gretchen Sassenrath (Kansas State University)
Co-Principal Investigators: Christopher Little (Kansas State University)
Kraig Roozeboom (Kansas State University)
Doug Shoup (Kansas State University)
Keywords:

Contributions

Contributing OrganizationAmount
Kansas Soybean Commission $23,308.00

Funding

Funded InstitutionAmount
Kansas State University $23,308.00

Information and Results

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Project Summary

Charcoal rot, caused by the fungus Macrophomina phaseolina, (Tassi) Goid, limits yield and performance of soybean. The fungus is highly prevalent in crop fields in eastern Kansas. Certain plants have been shown to produce chemicals that act as biofumigants that control or reduce harmful soil fungi, such as that which causes charcoal rot. Bacterial control of diseases has been used successfully in potato production (Larkin et al., 2011). Mengistu et al. showed some suppression of charcoal rot infestation with reduced tillage and use of rye as a cover crop (Mengistu et al., 2009). The research outlined here will test the ability of mustard to control charcoal rot and other soil-borne pathogens in soybean production. The research will develop standard protocols for farmers to incorporate cover crops into current production practices. Incorporating a cover crop into the crop rotation may be a simple method of controlling soilborne diseases while reducing use of fungicides that may contaminate the environment.
This research builds on previous research demonstrating that mustard reduces the number of CFUs of the charcoal rot pathogen. The research area will be expanded to include test fields in a second environment at Manhattan, KS.

Project Objectives

Develop agronomic practices integrating cover crops to control fungi causing charcoal rot and other soil-borne diseases in soybean production systems.

Project Deliverables

Previous research sponsored by the Kansas Soybean Commission demonstrated that a high-glucosinolate mustard with biofumigant properties reduces M. phaseolina population levels in soil and in soybean plants. The research in this new proposal builds on those results by developing management practices that incorporate use of mustard as a cover crop in soybean production systems, included double-cropped soybeans. The mustard cover crop will be tested for its impact on soil health, fungal disease presence, and soybean growth and yield.
a. Best management practices for implementing mustard seed cover crop. Mustard seed will be planted in the spring. Different methods of managing the mustard seed residue will be tested to determine the best method of controlling soil fungi. Prior to planting soybeans, the field will receive a herbicide burndown. Four different methods (and one control) will be used to determine how to manage the soybean residue for optimal fungal control, including: control (no mustard cover crop) no incorporation: plant into standing mustard no incorporation: cover crop rolled no incorporation: cover crop mowed incorporation: cover crop disked (tillage)
Soil samples will be collected prior to planting soybeans for determination of disease presence. Soybeans will be planted and grown to maturity. Soil and soybean plant samples will be collected at the R7-R8 growth stage and measured for amount of fungus infection.
b. Management practices for implementing mustard cover crop in double-cropped soybean production. Winter wheat with and without mustard seed will be planted in the fall.
After grain harvest in the spring, soil samples will be taken to measure the amount of charcoal rot fungus. Double-cropped soybeans will be planted and grown to maturity. Soil and soybean plant samples will be collected at the R7-R8 growth stage and measured for charcoal rot fungus.
Measurements:
Soybean will be planted in research plots at the Southeast Ag Research Center experiment fields outside of Columbus, KS, and in research plots at Ashland Bottoms, south of Manhattan, KS.
Production measurements will include in-season assessment of plant development and growth stage. Soil analysis will be performed to determine presence of disease-causing fungi before planting soybeans and again after harvest. Total soil microbial activity will be determined in collaboration with Ruiz-Diaz through the research proposed in his project.
Charcoal rot disease severity will be determined in the soil by counting the number of colony forming units (CFUs) using standard procedures. Charcoal rot disease severity will be measured in plants by randomly selecting ten plants per plot at the R7-R8 growth stage for root and stem severity rating. The plants will be scored by splitting the stem and taproot of each plant, and rating the degree of gray discoloration and microsclerotia in the vascular and cortical tissues on a scale of 1-5. M. phaseolina root population levels will be estimated by grinding the split roots after the severity evaluation. The ground plant tissue and soil samples will be plated on microbiological medium and incubated. CFUs of M. phaseolina will be counted and transformed to CFUs per gram of root tissue or gram of soil.
Sections of each plot will be hand-harvested at maturity to determine yield components of soybean (plants/acre; pods/plant; seed/pod; number of seed/acre; average seed weight and total seed weight/acre). Total plot yield will be taken with a plot combine and seed samples will be analyzed for seed size. Economic analysis will be performed by developing partial budgets for each treatment from harvested yield and total input expenses

Progress of Work

Update:
High-glucosinolate mustard was planted in research plots at Columbus, KS and Ashland Bottoms, KS. Treatments to manage mustard biomass were implemented. Soybeans were planted in the research plots. Soil samples were collected. Soils are being tested for number of colony forming units of the charcoal-rot fungus.

Update:
Previous research sponsored by the Kansas Soybean Commission demonstrated that a high-glucosinolate mustard with biofumigant properties (Mighty Mustard Pacific Gold, Johnny’s Select Seed) reduces M. phaseolina population levels in soil and in soybean plants. The research in this new proposal builds on the previous results by developing management practices that incorporate use of mustard as a cover crop in soybean production systems, included double-cropped soybeans. The mustard cover crop will be tested for its impact on soil health, fungal disease presence, and soybean growth and yield.
The mustard seed was planted in late March at two locations: Columbus, KS and Ashland Bottoms, KS, when soil temperatures were consistently above 50 F. The mustard seed germinated well (Figure 1). The mustard grew till bloom, and then was killed with herbicide. Four different treatments were implemented to test the potential impact of mustard biomass on charcoal rot fungus prior to planting the soybean seeds: planting directly into the standing mustard plants; rolling the mustard plants; mowing the mustard plants; and disking the mustard plants. A fifth control plot had no mustard cover crop. All plots were planted with an early maturing cultivar, AG4135.
Soil samples were collected after implementing the cover crop residue management treatments. Second soil samples were taken in the fall at the same time that soybean plant samples were taken at the R7-8 stage. The numbers of colony forming units (CFU’s) will be measured in the plant and soil samples at the Department of Plant Pathology at Kansas State University. Additional samples were used to determine soil microbial activity with the phospholipid fatty acid assay (PLFA). Soybean yields will be measured in each plot at harvest.

A second experiment tested the efficacy of mustard in wheat to control charcoal rot in double-cropped soybeans. Soil and plant samples for that study will be taken when the soybeans are at the R7-8 stage, and number of colony forming units measured. Soybean yield will be measured at maturity.

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Update:

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Updated April 17, 2018:

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Final Project Results

Benefit to Soybean Farmers

Best management practices will be developed for controlling charcoal rot disease in soybeans. Methods will be demonstrated at field days. The research will develop new methods of control for charcoal rot and other soil-borne diseases and test the efficacy of different residue management methods to control fungi.

Performance Metrics

Project Years

YearProject Title (each year)
2017Soybean production systems to control charcoal rot and other soilborne diseases