Morphological characterization and in vitro efficacy of bioagents against Alternaria alternata blight of pigeonpea

Abstract

The Alternaria blight of pigeonpea is an important foliar disease posing serious threat to pigeonpea cultivation due to change in the climatic condition, cultivation practices and variation in pathogenic character. Hence, the effective management of the pathogen needs its characterization and identification of effective bio-agent for the farming community. Among 20 isolates characterized for morphology, conidia of different isolates were separated by one or two vertical septa and 2-8 hortizontal septa and the maximum horizontal septa of 3-8 was exhibited by the isolates PLS-4 and PLS-10, respectively and the maximum size of the conidia was revealed by PLS18 and PLS19 with 226.52-394.60 mm × 75.40-105.40 mm and 233.04-374.48 mm × 71.40-101.44 mm, respectively. The isolate PLS 18 showed maximum beak length of 44.40-190.70 mm. Among the bioagents tested under dual culture, T. hamatum was found most effective and statistically significant over other bio-control agents in inhibiting the mycelial growth (82.78%) of Alternaria alternata followed by T. viride (78.61%).