Evaluation of aqueous botanical extracts and bio-agents against biotic stresses in paddy

Abstract

A field study was conducted during kharif 2011-12 and 2012-13 to study the efficacy of locally available weed plant species (Datura stromanium, Calotropis gigantean, Nerium indicum and Azadirachta indica) and bio-agents (Trichoderma viride and Pseudomonas fluorescens) against major pests (stem borer, gall midge and leaf folder) and diseases (sheath blight, sheath rot, leaf spots and false smut) prevalent in north coastal zone of Andhra Pradesh. Among the treatments, soil application of Pseudomonas fluorescens @ 2 kg/ac was found most effective in managing sheath blight incidence and promoting growth. Aqueous neem leaf extract @ 5 ml per liter was found statistically superior in managing stem borer incidence. However, none of the aqueous leaf extracts were found effective in minimizing false smut, gall midge and leaf folder. Soil application of P. fluorescens was the most effective recording 4624 kg/ha yield as against 4919 kg/ha in chemical treatment.