Virulence pattern and reaction to fungicides in Alternaria triticina, a leaf blight pathogen of wheat

On the basis of mean disease score of Alternaria triticina culture on Nl 5439, HD 2189. NI 8729 and Raj 1777 cultivars, virulence type was determined (mean disease score less than 5=less virulent). Reaction of fungicides on A. triticina culture was found to be dependent on the degree of virulence available. Less virulent and moderately virulent A. triticina was inhibited at lower or recommended concentration of the fungicides whereas highly virulent isolates required higher concentration of fungicides. This indicated that knowledge of type of virulence inciting disease in the field or in the area could be of great help in formulating the control of leaf blight caused by A. triticina.