CULTURAL AND PHYSIOLOGICAL CHARACTERISTICS OF ALTERNARIA SPP. CAUSING LEAF SPOT ON MUSTARD (ALTERNARIA BRASSICAE)MOIN KABIR1, AKHILESH CHANDRAPATI2 AND MEENAKSHI RANA3Abstract Mustard (Brassica juncea) is a major rabi oil seed crop out of total nine oil seeds crops in India. It belongs to family Brassicaceae and was introduced into China. Mustard is affected by various diseases i.e., Alternaria leaf spot, Downey mildew, Powdery mildew and White rust etc. Alternaria leaf spot is caused by various Alternaria species like brassicae, brassicicola, rafani, Alternata etc. in this experiment for testing the good growth of Alternaria spp. 7 different media are taken, i.e. rose bengal, czepak dox agar, potato dextrose agar, Richards synthetic media, corn meal, malt extract agar, oat meal agar. Among all the media malt extract agar was the best media for the growth of Alternaria spp. Also Richards media was quite good for the growth after malt extract. To check the factors that effect on growth of Alternaria spp. two different factors, i.e. pH and temperature have shown a significant change in growth of Alternaria spp. pH range taken from 4 to 9 and temperature from 15 to 35 oC. Best growth was observed with pH 5 and best growth observed at a temperature range between 23 to 25 oC. Weather conditions have a significant impact on the development of Alternaria spots on mustard. Warm weather conditions were found to be the primary that triggers for increased disease damage in some cruciferous species in this study. |