Project Details:

Title:
Developing tools to protect soybean stand from seedling disease caused by Pythium species

Parent Project: This is the first year of this project.
Checkoff Organization:Iowa Soybean Association
Categories:Soybean diseases
Organization Project Code:450-30-52
Project Year:2016
Lead Principal Investigator:Alison Robertson (Iowa State University)
Co-Principal Investigators:
Christopher J Anderson (Iowa State University)
Arti Singh (Iowa State University)
Keywords: Seedling disease, seed treatment, Pythium, damping off

Contributing Organizations

Funding Institutions

Information and Results

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Project Summary

To optimize yield, soybean farmers are planting earlier each year. It is not uncommon to have cold fronts (abundant rainfall and soil temperatures dropping below 55F) occurring during the planting period (mid-April through mid-May). Cold, wet soils slow the germination process and increase the risk of seedling disease caused by Pythium that can result in stand loss. As seed costs increase, it becomes economically important to ensure that every seed planted becomes a productive plant. Our proposed research “will increase soybean farmer competitiveness”, through the development of improved tools (seedling disease risk model, genetic markers for Pythium resistance and cold tolerance) that will improve “productivity and profitability while improving environmental stewardship”. Specifically, this project will improve our understanding of the soybean-Pythium interaction. We expect to identify the germination/emergence developmental stage(s) at which soybean is most susceptible to infection and evaluate the effect of cold stress on this susceptibility. These data together with data from seed treatment field trials (funded by ISA and industry) will be used to develop a seedling disease risk tool that soybean farmers could use to schedule planting to ensure successful stand establishment. Moreover, we will identify screen varieties that vary in cold tolerance for susceptibility to Pythium species to determine if there is a relationship.

Project Objectives

Objective 1: To determine how timing of cold stress affects susceptibility to Pythium
Objective 2: To identify when during germination and emergence are soybeans most susceptible to Pythium
Objective 3: To determine if cold tolerance and susceptibility to Pythium is correlated
Objective 4. To develop a seedling disease risk assessment model that growers could use to schedule planting

Project Deliverables

Improved understanding of soybean seedling disease biology
Identification of genetic markers for improved cold tolerance and Pythium resistance
Seedling disease risk model
Peer reviewed manuscripts
Tweets, blogs and newsletter articles

Progress of Work

Update:
Objective 1: To determine how timing of cold stress affects susceptibility to Pythium
A growth chamber study was done to determine the effect of cold stress at planting (40F for 96 h) and cold stress 24 after planting in the presence or absence of P. sylvaticum. Two runs of the experiment were done. Emergence differed between the runs and it was determined that seed moisture was lower in run 2 at planting, and it is likely that this confounded the results. In run 1, no difference in emergence was seen when soybean was exposed to 40 F for 96 h immediately at or 24 h after planting. In run 2, emergence was reduced in both cold stress treatments compared to the control. In the presence of P. sylvaticum, emergence was further reduced (P<0.01). A Blog regarding this experiment was posted on the ICM Blog (http://crops.extension.iastate.edu/blog/alison-e-robertson-mauricio-serrano/do-cold-wet-soils-increase-risk-soybean-seedling-disease)


Objective 2: To identify when during germination and emergence are soybeans most susceptible to Pythium
Preliminary trials to evaluate methodologies have been done. Inoculation using mycelial slurry resulted in good disease development.


Objective 3: To determine if cold tolerance and susceptibility to Pythium is correlated
Seed of 12 soybean varieties that vary in cold tolerance was ordered and received from the National Germplasm Resources Lab. Seed of each variety will be increased over the summer. Greenhouse and laboratory trials will begin in Fall 2016. Methods to screen the germplasm have been developed.


Objective 4. To develop a seedling disease risk assessment model that growers could use to schedule planting
Stand count and yield data from seed treatment field trials from across Iowa over the past 5 years have been compiled.

Final Project Results

Benefit to Soybean Farmers

Performance Metrics

Project Years