CONTROL OF ALTERNARIA BLIGHT OF MUSTARD THROUGH FERTILIZER AND FUNGICIDE APPLICATION

Abstract

The efficacy of different fungicides and micronutrients alone or in combination were evaluated against Alternaria brassicae causmg Alternaria blight of mustard. The experiments were conducted in-vitro and in-vivo in the Department of Plant Pathology, Sher-e-Bangia Agricultural University, Dhaka, Bangladesh during November 2007 to March 2008. Four fungicides namely Rovral 50 WP (0.2%), Dithane M-45 (0.45%), Ridomil gold MZ 72 (0.2%) and Bavistin (0.1%) and micronutrients (Zypsum, Zinc oxide and Boric acid) were tested. In in-vitro test, Rovral 50 WP inhibited the highest radial mycelial growth (68.91%) of Alternaria brassicae followed by Dithane M-45 (63.87%) Ridomil gold (55.46%) and Bavistin (50.42%) compared to control. In the field experiment, 10 treatments including spray of fungicides alone or in combination with micronutrients were evaluated against the disease. Among those treatments, Rovral 50 WP + Micronutrients showed the highest performance against Alternaria blight in terms of disease incidence and severity followed by application of Rovral 50 WP alone, Dithane M-45 + Micronutrients and Dithane M-45 alone. The treatment Rovral 50 WP + Micronutrients reduced the leaf infection, pod infection and leaf area diseased by 82.31%, 78.19% and 86.24%, respectively compared to control which was followed by application of Rovral 50 WP alone and Dithane M-45 + Micronutrients. The yield and yield contributing characters were influenced by the treatments where the highest yield was recorded in case of Rovral 50 WP + Micronutrients that was 39.80% higher over control. The performances of micronutrients were significantly better than control but the performances of. micronutricnts did not differ significantly while it was used in combination with fungicides compared to the application of fungicides alone.