Etiology, prevalence and management of curvularia leaf spot of maize in Karnataka.

Maize (Zea mays L) is an important food, fodder, fuel and feed crop grown in Karnataka. The crop is affected by number of diseases of which curvularia leaf spot is an important emerging foliar fungal disease during Kharif season. A survey conducted recently revealed that, the severity of curvularia leaf spot was prevalent in moderate to severe intensities on most of the hybrids grown in Karnataka during rainy season and cause extensive damage to the crop thus lowering yields. The disease severity ranged form 20.50 to 63.6 per cent. High disease severity was recorded in Dharawad, Haveri and Belagum districts during tasselling to post flowering stage of the crop. Hot and humid climate favoured the development of disease during flowering to grain filling stage. The diseased samples were analyzed. Microscopic examination of the cultures of different locations revealed association of two species of curvularia namely, Curvularia lunata and Curvularia eragrostidis. The most prominent was Curvularia lunata followed Curvularia eragrostidis. Maize leaf extract and sucrose @ 5 per cent enhanced conidial germination. Field management studies revealed that, Trifloxystrobin 25% + Tebuconazole 50% (Nativo 75WG) @0.1% as foliar application found effective in reducing disease severity. Tebuconazole 250EC and Propiconazole 25EC @ 0.1% also found effective in reducing the severity.