Pantnagar Journal of Research

Abstract

Among oilseeds Brassica, mustard (Brassica juncea) is one of the most important oilseed crops being cultivated in India. The crop is attacked by several diseases. Among them Alternaria leaf blight is one of the most destructive diseases caused by fungus Alternaria brassicae. The yield loss caused by this pathogen is between 10-70 per cent. Since no resistant variety against the disease is available, therefore farmers mainly dependent on the recommended fungicides which are not much effective when disease occurs in severe form. Keeping in view some new chemical fungicides were evaluated under field conditions in two successive years (2011-12 & 2012-13). Among them Nativo 75 WG (Tebuconazole 50 % +Trifloxystrobin 25% w/w) and Tebuconazole 43 EC each at 0.05% were found significantly most effective with minimum occurrence of the disease severity index (DSI) on leaves (0.0 & 0..0%) at 90 days after sowing (DAS), and on pods (5.56 & 7.41 %) at 110 DAS as compared to other treatments and standard check Mancozeb 75 WP @ 0.2% in which DSI on leaves and pods was 11.11 and 15.28 percent while in check it was 43.52 and 26.85 percent respectively. Maximum mustard grain yield was obtained with Nativo 75 WG (2550.67 kg/ha) followed by Tebuconazole 43 EC (2482.33 kg/ha) and Difenaconazole 25 EC (2392.33 kg/ha) and was at par with each other but significantly different from other treatments as well standard check Mancozeb 75 WP (2166.00 kg/ha) and check (1512.67 kg/ha). The highest net return was obtained with Tebuconazole 43 EC (Rs.31100.00/ha) followed by Nativo 75 WG (Rs. 25485.00/ha) and Propiconazole (Rs. 25273.00/ha) as compared to standard check Mancozeb (Rs. 19818.00/ha).