EFFICACY OF TRICHODERMA AND BOTANICALS IN CONTROLLING ALTERNARIA LEAF BLIGHT OF MUSTARD AND STUDY ON MORPHOLOGY OF THE PATHOGEN

Abstract

Experiments were conducted at the Farm of Bangladesh Agricultural Research Institute (SARI), Joydevpur, Gazipur and in the laboratory of Plant Pathology division, during rabi season from the month of November' 2009 February'20IO to evaluate the efficacy of some selected Trichoderma harzianum strains and plant extracts against Alternaria brassicae and Alternaria brassicicola causing gray blight of mustard (Brassica campestris var. BARI Sarisha-I5). Three Trichoderma harzianum strains and three plant extracts viz. Bashok (Adhatoda vasica) leaf extract, Bishkatali leaf extract and Marigold (Tagetes patula) were explored in the experiment. Among the Trichoderma harzianum strains and plant extracts, Trichoderma harzianum SI showed the best performance in reducing disease incidence an~ disease severity as well as increasing seed yield against leaf blight of mustard. Seed infection by Alternaria spp. was reduced by 64.79% and seed yield was increased by 48.19% over control by the application of Trichoderma harzianum S1. Among the botanicals, Marigold showed the better performance. No promising results were shown by the rest of the treatments against leaf blight of mustard.