In-vitro evaluation of fungicides, botanicals and bio-agents against Alternaria porri

Abstract

Onion (Allium cepa L.) is one of the major bulb crop in India, and it is widely cultivated species of genus Allium belongs to the family Alliaceae, Purple blotch of onion caused by Alternaria porri (Ellis) cif. is one of the most destructive disease causing heavy loss under field conditions. To know the efficacy of different fungicides, botanicals and bio-agents, were tested under in-vitro condition. Mancozeb75 WP was effective in controlling the mycelial growth of A. Porri with per cent mean inhibition of (97.68 %), followed by Difenconazole 25 EC (95.75 %). Among the five botanicals tested, Garlic (84.51%) was significantly superior over all other plant extracts evaluated. The next best treatment was Pongamia leaf extract (80.81%) and Neem (74.32%). In-vitro evaluation of bio-agents revealed that T. harzianum isolate 1 (83.10%) which was significantly superior over other isolate tested. Least inhibition was noticed in Pseudomonas fluorescens isolate 1 (51.52%).