Effect of certain fungicides and botanicals against early blight of tomato caused by Alternaria solani (Ellis and Martin) under Allahabad Uttar Pradesh, India conditions.

The effect of fungicides, namely mancozeb (0.2%), zineb (0.2%) and carbendazim(0.05%), botanicals i.e. Azadirachta indica (neem) leaf extract (20%), Eucalyptus chamadulonsis (eucalyptus) leaf extract (5%) and Allium sativum (garlic) extract (5%) was evaluated in a field experiment conducted at the research plot of the Department of Plant Protection, SHIATS, Allahabad, Uttar Pradesh, India, during the 2012-13 rabi seasons for the management of early blight of tomato caused by Alternaria solani. The lowest percent disease incidence (PDI) was observed in mancozeb (18.36) followed by carbendazim (25.62) and zineb (27.84) treatments. Similarly, the highest yield of tomato fruits was recorded with mancozeb (246.40 q/ha) followed by carbendazim (221.50 q/ha), zineb (208.85q/ha) when sprayed three times at an interval of 15 days starting from the initiation of the disease. The botanicals, namely neem leaf extract (30.66 PDI), garlic bulb extract (32.44 PDI) and Eucalyptus leaf extract (34.07 PDI) were also effective in reducing disease incidence and increasing fruit yield by 170.60, 154.40 and 164.40 q/ha, respectively. The highest cost benefit ratio was obtained with mancozeb treatment (1:4.15) followed by carbendazim(1:3.73), however, zineb (1:3.49), neem leaf extract(1:2.88), garlic bulb extract and eucalyptus leaf extract were promising in obtaining higher returns up to 1:2.79 and 1:2.61, respectively.