POTENTIALITY OF PLANT EXTRACT IN CONTROLLING LEAF BLIGHT (Bipolaris sorokiniana) OF WHEAT

Abstract

Potentiality of plant extract in controlling leaf blight (Bipolaris sorokiniana) of wheat was carried out during the period from june, 2006 to March, 2007. The experiments were conducted in the Seed Health Laboratory, Department of Plant Pathology and in the farm of the Sher-e-Bangla Agricultural University, Dhaka. Primarily 24 plant species were evaluated for their antifungal activity against B. sorokiniana by an invitro test. Among them 13 species were found promising and selected for field evaluation against leaf blight disease. All the plant extracts reduced the incidence of B. sorokiniana over untreated control. The highest reduction was found in case of treating seeds with turmeric rhizome extract. Among the botanicals, durba leaf extract performed the highest percent of healthy seedlings. It has been observed that allamanda leaf extract showed the highest germination and highest vigor index in compare to control. Among the botanicals onion bulb extract treated seeds resulted lowest leaf blight severity in compare to untreated control. Seed treatment with onion bulb extract also showed the best result in producing higher number of spikelets/ear, number of grains/ear, weight of grain/panicle and weight of straw/panicle in compared to untreated control. The treatment T 2 (Onion bulb extract) and T (Allamanda leaf extract) resulted highest grain yield (3.92 g/plot) over untreated control.