Survival of Alternaria burnsii on seed was 100% during April and May, which decreased to 70% during October, November under laboratory condition (25°C temperature and 40–50% RH). Whereas, in crop debris buried, its survival was 40–60% during October, November, 2009. Maximum temperature between 29–35.5°C, minimum temperature 9.6–19.7°C, average relative humidity of > 60% in the morning and > 28% in afternoon, wind speed 2.1–4.8 km/hr and 8 -10.4 bright sunshine hours were found favorable for disease development. Prevalence of Trichoderma harzianum showed maximum growth inhibition of 82.02%, whereas Pseudomonas aeruginosa showed growth inhibition up to 56.18% under in vitro condition. Tebuconazole (0.05%) was found to be most effective with 19.66% disease intensity (PDI), maximum disease control (71.9%) and highest seed yield (359.44 kg/ha), followed by propiconazole (0.1%), and mancozeb, against Alternaria blight of cumin under field condition. Seed treatment with thiram @ 3g/kg + 4 sprays of tebuconazole, 0.05% recorded highest test weight of 5.67g as compare the control (2.26 g).
Alternaria burnsii, Survival, Epidemiology, blight, neem leaf extract, biological agents, fungicides
