International Journal of Scientific and Research Publications, Volume 3, Issue 10, October 2013 1 ISSN 2250-3153 www.ijsrp.org Management of Turcicum Leaf Blight of Maize Caused by Exserohilum Turcicum in Maize T. Rajeshwar Reddy 1 , P. Narayan Reddy 2 , R. Ranga Reddy 3 , S. Sokka Reddy 4 1 PG student, Department of Plant Pathology, College of Agriculture, Acharya N G Ranga Agricultural University, Rajendranagar, Hyderabad - 500030, Andhra Pradesh, India. 2 Professor, Department of Plant Pathology, College of Agriculture, Acharya N G Ranga Agricultural University, Rajendranagar, Hyderabad - 500030, Andhra Pradesh, India. 3 Principal Scientist & Head, Maize Research Station, ARI, Rajendranagar, Hyderabad - 500 030, Andhra Pradesh, India. 4 Professor & Head, Department of Biotechnology, College of Agriculture, Acharya N G Ranga Agricultural University, Rajendranagar, Hyderabad - 500 030, Andhra Pradesh, India. Abstract- Seven fungicides were evaluated in vitro against Exserohilum turcicum causing leaf blight of maize The treatment mancozeb 0.25% and combination treatments of carbendazim and mancozeb i.e. saff 0.25% recorded the lowest percent disease index (PDI) reducing the disease by 73.0% and 72.1% respectively. The treatment which had a combination metriram + pyraclostrobin i.e. cabriotop 0.3% was found to be the next best treatment in reducing the disease by 61.5% with PDI of 14.6 following propiconazole with PDI of 18.6. Index Terms- Maize, turcicum leaf blight, Exserohilum turcicum, Mancozeb, Management I. INTRODUCTION aize is one of the important cereal crops and it is 3 rd major crop in India after rice and wheat. The crop is affected by number of fungal diseases of which leaf blight or northern corn leaf blight or turcicum leaf blight is one of the important diseases affecting photosynthesis with severe reduction in grain yield to an extent of 28 to 91%. Disease symptoms first appear on the leaves at any stage of plant growth, but usually at or after anthesis. The maneb formulations were most effective in minimising the E. turcicum severity under field conditions followed by ziram, vacide and Z-65. These fungicides increased the grain yield and seed quality (Cox, 1956). Sohi et al. (1965) tested six fungicides for the control of leaf blight on maize hybrid Ganga-5 and found that zineb was found more effective fungicide in controlling the disease with an increase in grain yield of 15.18 per cent followed by captan (10.19 %) over check plots. Foliar application of fungicides like mancozeb, propiconazole and zineb have been found to be effective against southern leaf blight of maize caused by Helminthosporium maydis. Seed dressing with maneb, captan, carboxin + thiram and benomyl + thiram improved seed germination (Miller, 1970). Kumar et al. (1977) evaluated eight fungicides and found that mancozeb, unizeb and dithane-Z-78 significantly reduced the maize leaf blight severity by 55, 47.4 and 44.43 per cent, respectively, and increased grain yield by 8.54, 10.12 and 9.90 per cent. Field trials conducted by Issa (1983) in Brazil revealed that mancozeb @ 2 kg ha -1 as foliar spray was found to be effective in reducing turcicum leaf blight severity in maize. This treatment gave the maximum number of healthy leaves and improved yield over untreated plots. Patil et al. (1984) reported that vitavax was found to be the best seed dresser against Drechsler spp. of barley. Three sprays of propiconazole at weekly interval was effective in reducing the rate of turcicum leaf blight development in maize (Bowen and Pederson, 1988). Kachapur and Hegde (1988) tested seven fungicides and observed that mancozeb and captafol were the most effective fungicides for controlling turcicum leaf blight of maize. Sharma and Mishra (1988) found that E. turcicum infection of maize was effectively controlled by six sprays of mancozeb (0.2 %) at 10 days interval starting from three days after inoculation at 30 days after sowing. The infection rate and severity rating were reduced and the grain yield was increased with this treatment. Begum et al. (1993) evaluated five fungicides for control of artificial infections of E. turcicum on susceptible maize cultivars. All the chemicals reduced disease intensity and increased the grain yield with mancozeb being distinctly the most effective, followed by carbendazim, zineb, thiophanate methyl and lastly copper oxychloride. Pandurangegowda et al. (1993) tested the field efficacy of eight fungicides and found that foliar spray of mancozeb (0.25 %) and maneb (0.25 %) thrice at an interval of 10 days were significantly effective in minimising the disease intensity of turcicum leaf blight. Praveen Kumar et al. (2010) reported that the combinations of the mancozeb (0.25 %) + T. viride (0.4 %) + mono potassium phosphate (1 %) + potassium silicate (1 %) were found effective in reducing turcicum leaf blight. In this paper studies were conducted on management of turcicum leaf blight of maize caused by Exserohilum turcicum using seven fungicides. II. MATERIALS AND METHOD In order to identify a suitable fungicide for the control of tucicum leaf blight a field experiment was carried out at Agriculture Reaserch Institute, Rajendranagar, Hyderabad during Rabi season 2011-12. The maize cultivar pioneer 30V 92 was sown in a randomized block design with a spacing of 70 × 25 cm with three replications. The details of the treatments are given in Table 1. M