In vitro evaluation of plant extracts, biocontrol agents and fungicides against leaf blight in pigeonpea

Abstract

Leaf blight is one of the important foliar diseases in pigeon pea. The causal agent associated with pigeonpea leaf blight was identified as Alternaria alternata based on the colony morphology and conidial characters. In vitro efficacy of five botanicals viz., garlic (bulb extract 5%), zimmu (leaf extract 10%), neem leaf extract (10%) tulasi (leaf extract 10%), and notchi (leaf extract 10%), five Bacillus subtilis strains and five fungicides were evaluated against the mycelial growth of A.alternata. The botanical viz., garlic bulb extract (5%) recorded 70 per cent inhibition of mycelial growth of A. alternata over control. The B. subtilis viz., CcB1strain of, exhibited the least mycelial of growth of 2.8cm with the highest growth inhibition of 68.9 percent. Among the five fungicides, Fluopyram SC 500 showed 100 per cent mycelial growth inhibition of A. alternata at 1000 ppm concentration.