| Abstract: | A Phialophora sp. (isolate I-52), originally isolated from soil in a wheat field exhibiting suppression of take-all disease caused by Gaeumannomyces graminis var. tritici , was tested under field conditions for its ability to suppress this disease in winter and spring wheat. I-52 was grown on a variety of autoclaved organic substrates, including oat, millet and canola seed. All of these gave significant disease control when added to the seed furrow with inoculum of the take-all fungus. W hole seed of I-52 substrate was as effective as particles < 0.5 mm in diameter. Placing I-52 in powdered form directly on to wheat seed was ineffective in controlling take-all. Rates as low as 2 g of I-52/3.3 m of row added with the seed provided some control of take-all, and nearly complete control in winter wheat was obtained using 15 g/3.3 m. The winter wheat host cultivar did not influence the degree of control of take-all by I-52. |
