Integrated disease management of leaf blight of taro.

摘要

A field trial was conducted during kharif 2006 and 2007 in Faizabad, Uttar Pradesh, India, to investigate the efficacy of oilseed cakes, plant extracts and a fungicide in controlling leaf blight (caused by Phytophthora colocasiae) of taro (Colocasia esculenta var. antiquorum [C. esculenta]) cv. Narendra Arvi-2. The treatments comprised: soil application of mahua [Madhuca longifolia] cake (T1), mustard cake (T2) and neem [Azadirachta indica] cake (T3), seed treatment with Ridomil MZ 72 WP [metalaxyl+mancozeb] at 2.5 g/kg+two foliar spray of Ridomil MZ 72 WP at 2.5 g/l water (T4), T1+two foliar spray of Ridomil MZ 72 WP at 2.5 g/l water (T5), T2+two foliar spray of Ridomil MZ WP at 2.5 g/l water (T6), T3+two foliar spray of Ridomil MZ 72 WP at 2.5 g/l water (T7), two foliar spray of tulsi [Ocimum tenuiflorum] leaf extract (black) at 10% (T8), two foliar spray of tulsi leaf extract (green) at 10% (T9), two foliar spray of neem leaf extract (green) at 10% (T10), and two foliar spray of garlic bulb extract (green) at 10% (T11), and control (water spray) (T12). During kharif 2006 and 2007, the minimum disease incidence of 44.94 and 45.15%, disease intensity of 14.74 and 13.31%, and coefficient of disease index of 6.62 and 6.00 was recorded in T4, with maximum cormel yield of 182.39 and 180.56 q/ha. Among the 12 treatments, T7 resulted in the minimum disease incidence of 57.34 and 58.71%, disease intensity of 20.62 and 19.58%, coefficient of disease index of 11.82 and 11.38 and maximum cormel yield of 154.56 and 153.90 q/ha during kharif 2006 and 2007, respectively. Among the treatments involving plants extracts, T10 recorded the minimum disease incidence (72.18 and 72.73%), disease intensity (26.81 and 25.41%), coefficient of disease index (19.36 and 18.48%) and cormel yield (128.01 and 127.12 q/ha) during kharif 2006 and 2007, respectively.