| A total of ten isolates of Botrytis cinerea infecting chickpea in most chickpea growing areas of Bangladesh were characterized in terms of cultural, morphological, physiological and pathogenicity. The isolates varied significantly in cultural, morphological and pathogenic traits- colony color, shape, margin and texture; production and arrangement of sclerotia on PDA medium. The optimum temperature and pH for the mycelial radial growth of B. cinerea were recorded at 20°C and pH 4.5, respectively. The mycelial radial growth of all ten isolates increases with the time for a certain period. No growth was observed at 35°C temperature. The pathogen B. cinerea grew well on CDA medium. The highest (79.17 mm) mycelial radial growth was obtained on CDA. The quickest (5 days) sclerotia initiation was observed on CDA and LDA culture media but the highest number (2.5×l04 ml-1) of spores were counted on LDA medium. The length of conidia varied from 5 to 15 um. Mean length of conidia was maximum 12 μm in isolate AHI-9 and minimum 7.50 mμ in isolate AHI-1. The breadth of conidia ranged from 5 to 10 μ. The highest mean breadth 8.25μm was observed in isolate AHI-9 and the lowest 6 μm in isolate AHI-4. The isolates exhibited different reaction of highly susceptible to resistant to a set of chickpea cultivars and AHI-9 and AHI-10 were found the most virulent isolates among the others. The antagonist Trichoderma harzianum appeared to be a good bio-control agent against B. cinerea. Among the seven tested fungicides namely- Bavistin 50WP (Carbendazim), CP-Zim 50WP (Carbendazim), Sunphanate 70WP (Thiophanate methyl) and Rovral 50WP (Iprodione) were the most effective fungicides to inhibit the mycelial radial growth of B. cinerea at a lower concentration (500 ppm). |
