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.
