Take-all is the most important root disease of wheat worldwide. In the Pacific Northwest, it can be devastating and farmers have no economically viable method to control the disease. For example, results of a formal survey in 1983 revealed yield reductions of 350,000 tons over the entire PNW region. Recent informal surveys indicate that the disease is now even more widespread than previously thought. Beyond its effect on productivity, take-all also increases problems associated with water and air pollution and soil erosion. It has been demonstrated that fluorescent Pseudomonas spp., isolated from soils that are naturally suppressive of take-all, are able to suppress the disease when applied as seed treatments. Yield increases of 10-25% commonly have been obtained in field tests. We propose to scale-up this biocontrol technology and test the feasibility of incorporating it into existing wheat production practices. Specifically, we will conduct on-farm tests at several geographically diverse locations using three different systems for delivering the bacteria.
Anticipated Results:Results will determine whether the research- level effectiveness of the biocontrol for take-all disease in wheat can be transferred directly to conventional production systems used by farmers in the PNW. It will also indicate which one of several strains of bacteria is most effective in the highly variable growing environment of farmer fields and which mass delivery system enhances root colonization and antibiotic production best.- This data will lay the groundwork for adapting the most effective technology to farmer crop management practices in Phase II of the grant program and scaling up bacteria production and seed treatment.
