Factors influencing pathogenicity of three isolates of colletotrichum graminicola on wheat

Summary Factors such as varieties of wheat, hydrogen ion and various mineral salts concentrations of soil having possible influence on the pathogenicity of certain isolates ofColletotrichum graminicola (Ces.)Wils. on wheat were studied. Of the six varieties of wheat studied, the variety Dual was highly susceptible, and the variety Knox highly resistant. The percentage seedling blight was greatest in soil at the highest pH values, 7.0–9.0. Concentrations of potassium nitrate, ammonium nitrate and magnesium sulfate in soil greatly influenced disease development.Portion of a Ph. D. thesis, Department of Botany and Plant Pathology, The Ohio State University, Columbus-10, Ohio, U.S.A.