MANAGEMENT OF ALTERNARIA BLIGHT OF RADISH (Raphanus sativus L.) SEED CROP WITH FUNGICIDES, BAU-BIOFUNGICIDE AND MICRO-NUTRIENTS

Abstract

Radish (Raphanus sativus L., n = 9) belonging to the family cruciferae, is the third most important vegetable crop of Bangladesh. The high yielding tropical annual type Tasaki Mula was used in this study. The Dinajpur region is one of the most important seed growing regions of Bangladesh. Therefore, the present study has been carried out in Dinajpur region. The application of two foliar fungicides (Iprodione, Mancozeb), bioagent means (BAU-Biofungicide) and three micro-nutrients (Boron, Zinc and Magnesium) were applied in controlling the Alternaria blight on radish seed crop during rabi season of 2007-2008. Disease and yield data were assessed in terms of percent leaf area diseased, percent pod area diseased, 1000-seed weight (g) seed, yield per plant (g) and seed per hectare yield (t/ha). The percent diseased seed and germination percentage were recorded after harvest of the crops. Sprays were commenced from the first appearance of disease symptoms at 51 day old transplanted crop. Iprodione, Mancozeb and BAU-Biofungicide had significant effect on reduction of disease and increasing of seed yield. Among the fungicides, remarkable reduction of leaf area diseased was observed with Iprodione sprayed plots followed by BAU-Biofungicide but incase of pod area diseased, there was no significant difference between Iprodione and BAUBiofungicide sprayed plots. The result of yield per hectare (1.18 t/ha) were found significantly higher in Iprodione sprayed plots followed by BAUBiofungicide (1.07 t/ha) over control (0.47 t/ha). The foliar application of Iprodione had a significant effect on seed quality. The highest diseased seed (70.89%) was recorded in seed that control plots where the lowest (36.86%) was recorded in Iprodione sprayed plots that received seven sprays followed by BAU-Biofungicide (41.05%). Percent germination was significantly influenced by foliar spray with fungicides. The lowest germination (75.75%) was recorded in seed samples that were collected from control plots, but the highest (86.50%) was recorded where seven sprays of BAU-Biofungicide was applied. Incase of economic consideration, the plots of BAU-Biofungicide gave the maximum net return (Tk. 1,66,000/-) having BCR of 4.32. Therefore, it may be concluded that among the spray materials BAU-Biofungicide with seven sprays plays the best role in reducing the Alternaria blight and significantly increase the seed yield with good quality.