This investigation was undertaken to detect the fungi associated with Capsicum frutescens during June, 2017 to June, 2018. Samples with anthracnose symptoms of chilli fruits were collected from Karwan Bazar and Ananda Bazar of Dhaka city and Badalgachhi, Naogaon. Fungi associated with the diseased chilli were isolated separately following tissue planting method (CAB 1968). Identifications of the isolates were determined following the standard literature.
Five chemical fungicides viz., Capvit 50 WP, Contaf 5 EC, Greengel 72 WP, Knowin 50 WP and Score 250 EC were collected from the Siddique Bazar, Dhaka. These fungicides at 100, 200, 300, 400 and 500 ppm concentrations were evaluated against Colletotrichum dematium and C. gloeosporioides according to Islam et al. (2017). A total of five plant parts viz., Acalypha indica, Azadirachta indica, Heliotropium indicum, Lippia alba and Magnolia champaca were evaluated for their effect on the radial growth of test pathogens at 5, 10, 15 and 20% concentrations according to Islam et al. (2017). The plant parts were collected from the Botanical Garden of Curzon Hall Campus, University of Dhaka. The data were collected as inhibition percentage of the radial growth of the pathogen in mm in each replication and evaluated by ANOVA using STAR statistical program and means were compared using DMRT.
Alternaria alternata, A. tenuissima, Aspergillus flavus, A. niger, Colletotrichum dematium, C. gloeosporioides, Curvularia clavata, Fusarium semitectum and Rhizopus stolonifer were isolated from the infected Capsicum frutescens. Among the isolated fungi, C. dematium and C. gloeosporioides were selected as test pathogens owing to their pathogenic potentiality.
The efficacy of fungicides on the radial growth of C. dematium and C. gloeosporioides at 100, 200, 300, 400 and 500 ppm are presented in Table 1. Out of five fungicides, the complete inhibition of the radial growth of C. dematium was observed with Capvit 50 and Score 250 at all the treated concentrations (Table 1). Similarly, Banginwar et al. (2012) reported that Capvit 50 showed complete growth inhibition of C. dematium. Contaf 5 also showed complete growth inhibition of C. dematium at 200, 300, 400 and 500 ppm concentrations. The complete inhibition of radial growth of C. gloeosporioides was observed with Contaf 5 at all the concentrations whereas Score 250 showed complete growth inhibition at 500 ppm concentration (Table 1). Hosen et al. (2016) found complete growth inhibition of C. gloeosporioides by Capvit 50 and Greengel 72 at 500 ppm only. Patil and Nargund (2016) reported that Contaf 5 and Score 250 completely inhibited the mycelial growth of C. gloeosporioides at all the concentrations except 100 ppm. Laboratory evaluation of fungicides revealed that all the fungicides caused partial or complete inhibition of Colletotrichum dematium and C. gloeosporioides at 500 ppm (Table 1). The same fungicides also showed different effects on different pathogens in the present investigation due to the selection of different strains of test pathogens.