Management of Purple blotch disease of Onion under field condition

Abstract

Onion (Allium cepa L.) is one of the oldest known and an important vegetable crop grown in India. Productivity of onion is affected by many biotic and abiotic stresses. Among the biotic stresses diseases play an important role and among them, purple blotch caused by Alternaria porri is one of the most destructive disease. The study was conducted to check the efficacy of different fungicides and bio-agents under field condition. The results revealed that among the chemicals Difenconazole 25 EC (Score) @ 0.1 % was found effective in reducing the disease with a per cent disease reduction over control of (62.23) was onpar with (Tebuconazole + Trifloxystrobin) @ 0.05 % (60.51). Among the bio-agents tested Trichoderma harzianum was found effective with the per cent disease reduction over control of (54.47) followed by treatment with a combination of Trichoderma harzianum and Pseudomonas flouroscens (41.91).