Management of leaf blight complex of wheat (Triticum aestivum) caused by Bipolaris sorokiniana and Alternaria triticina in different agroclimatic zones using an integrated approach

A multi-locations trial on integrated management of leaf blight was conducted at Karnal, Pantnagar, Faizabad, Coochbehar and Dharward centres during 2001-03. The treatments used were different doses of NPK fertilizers, seed treatment and foliar sprays of fungicide, botanical (neem-based pesticide) and bio-control agent, Trichoderma harzianum isolate DWRLB 1 in field. The popular wheat (Triticum aestivum L. emend. Fiori & paol) cultivars used were 'PBW 343', 'K 9107' and 'MACS 2846'. The foliar sprays with propiconazole@0.1% (Tilt 25 EC) beginning from appearance of disease and later at 15 days intervals thrice, reduced the leaf blight incidence most and increased the grain yield ranging from 9 to 99% over untreated control. The use of neem-based pesticide and T. harzianum also proved effective in reducing the leaf blight incidence. Carboxin @ 0.25%, as well as diferent does of K fertilizer @ 0,40 and 60 kg/ha, could not reduce the incidence of disease significantly. The cost:benefit ratio foliar sprays of propiconazole was 1.0:13.6, 1.0:3.8 and 1.0:2.0 during 2001-02 season, whereas that of seed treatment with carboxin and foliar sprays of propiconazole was 1.0:6.4, 1.0:2.6 and 1.0:2.4 in 2002-03 crop season in peninsular north-eastern plains and north-western plains zone of India, respectively.