Fungistasis of Trichoderma culture filtrates against Alternaria lini causing bud blight of linseed

Alternaria lini is an economically important fungal pathogen that causes bud blight disease of linseed. This disease is prevalent on linseed crop inall the linseed growing areas of India. Ten isolates of A. lini having different morphological and cultural characteristics were collected from genetically different lines of linseed. The effect of culture filtrates of four species of Trichoderma i.e. T. viride, T. hamatum, T. harzianum and T. virens were evaluated on mycelial growth of A. lini by poisoned food technique. The maximum inhibition of mycelial growth was recorded for culture filtrate (10%) of T. harzianum caused 53.36% inhibition of radial mycelial growth. Under pot culture conditions, culture filtrate of T. harzianum @ 10% was evaluated as spray application with three time schedules i.e. 30 hr before, 30 hr after and 60 hr after inoculation of pathogen. The spray of 10% culture filtrate of T. harzianum after 30 hr of inoculation was the most effective and resulted into 55.87% reduction of disease followed by spray after 60hr of inoculation of pathogen that has given 55.04% reduction of disease.