In vitro evaluation of plant extracts, bio-agents and fungicides against Purple blotch and Stemphylium blight of onion

Abstract

Eight plant extracts, bio agents and fungicides were evaluated in in vitro conditions against purple blotch and Stemphylium blight of onion caused by Alternaria porri and Stemphylium vesicarium. Among the plant extracts, clove extracts of Allium sativum at 10% resulted in maximum inhibition of growth (58.05 and 57.31%) of A. porri and S. vesicarium,respectively followed by Aloe vera at 10% (53.5 and 47.15%). Among the bioagents,Trichoderma viride was effective in inhibition of growth (53.17 and 56.15%). Out of eight fungicides evaluated, Mancozeb at 0.2% completely inhibited the growth of both the pathogens. Azoxystrobin (0.1%), propiconazole (0.1%) and antracal (0.2%) were the other effective fungicides.   Key words: Onion, Allium cepa, Alternaria porri, Stemphylium vesicarium, management.