Integrated Management of Alternaria Leaf Spot of Cauliflower under Pot Conditions

Abstract

Cauliflower is widely grown throughout the world. Alternaria leaf spot of Cauliflower caused by Alternaria brassicae is the most destructive disease at the curd stage and seed setting stage, attributed to causing 30-50% losses and in severe cases reaching up to 98% in seed crop. In the present investigation, the pathogen Alternaria brassicae was found to produce typical symptoms of the disease as small, irregular brown spots with concentric rings, also surrounded by a yellow chlorotic halo.  Later on, lesions were found to coalesce forming irregular, brown to dark brown patches with concentric rings. The disease is difficult to manage alone with fungicides or bio agents or botanicals. Hence the present study was undertaken to manage the disease effectively by application of fungicides, bio agents, botanicals and their combinations. During the investigation on integrated management under sick pot conditions, the combination of T. viride + Neem + Azoxystrobin (10.81% Percent Disease Index) was found most effective with inhibition of disease by 79.02%. This was followed by T. viride + Azoxystrobin (11.63% Percent Disease Index) with inhibition of the disease by 77.40% compared to the control 51.52% Percent Disease Index.