Significance of Lasiodiplodia theobromae and Colletotrichum musae in causing crown rot in banana and their reaction on some commercial banana cultivars

Abstract

Crown rot is an important post-harvest disease of banana infecting the pad of cut hands. Among the 108 isolations made from samples of 16 commercial banana cultivars from different regions, 40 isolations yielded Lasiodiplodia theobromae, 22 isolations yielded Colletotrichum musae 34 isolations yielded both L. theobromae and C. musae, 6 isolations yielded L. theobromae C. musae and Fusarium spp. and only 6 isolations yielded Fusarium spp. Artificial inoculation with single species and combinations on cv. Robusta revealed, the combination of L. theobromae and C. musae and L. theobromae C. musae and Fusarium spp. produced the highest level of rotting on ripe fruits. Cultivar Robusta (AAA) and Dwarf Cavendish (AAA) were highly susceptible and cv. Karpuravalli (ABB), Nendran (AAB) and Virupakshi (AAB) were found to be least susceptible to crown rot disease complex under artificially inoculated conditions. This was confirmed by in vitro testing of the fruit leachates of ten banana cultivars on spore germination of the most virulent isolates of L. theobromae and C. musae.