VARIABILITY, PATHOGENICITY AND IN VITRO MANAGEMENT OF BOTRYTIS GRAY POT IN CHICKPEA (CICER ARIETINUM L.)

Abstract

total of ten isolates of Botry tis cinerea infecting chickpea in most chickpea growing areas of Bangladesh were characterized in terms of cultural, morphological. physiological and pathogenicuy. 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 pl I for the mycelial radial growth of Botrytis cinerea were recorded at 2ouc and pl l 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 Botry tis cinerea grew well on CDA medium. The highest (79.17 mm) mycelial radial growth was obtained on COA. The quickest (5 days) sclerotia initiation was observed on CDA and LOA culture media but the highest number (2.5 x 10'1 ml") of spores were counted on LOA medium. The length of conidia varied from 5 00 to 15 00 µm. Mean length of conidia was maximum 12.00 µm in isolate Alll-9 and minimum 7.50 µm in isolate AHl-1. The breadth of conidia ranged from 5.00 to 10.00 µm. The highest mean breadth 8.25 urn was observed in rsolate AHT-9 and the lowest 6 00 µm in isolate £\I 11-4. The isolates exhibited different reaction of highly susceptible lo resistant to a set of chickpea cultivars and Al Il-9 and AI 11-10 were found the most virulent isolates among the others. The antagonist Trichoderma harzianum appeared to be a good bio-cornrol agent against Botrytis cinerea. Among the seven tested fungicides namely- Bavistin" SOWP (Carbendazirn), CP-Z1m 50WP (Carbendazirn), Sunphunate 70WP (Thiophanate methyl) and Rovral SOWP (Iprodione) were the most effeciiv e fungicides to inhibit the mycelial radial growth of Botrytis cinerea at a lower concentration (500 ppm).