Investigations on the etiology epidemiology and integrated management of rhizome rot complex of ginger and turmeric

Abstract

The major constraint for cultivation of ginger and turmeric is the rhizome rot disease. newlineThe rhizome rot incidence of ginger was noticed in all the locations surveyed with the range newlinefrom 5.50 to 45.60 per cent. The major diseases diagnosed were viz., soft rot caused by newlinePythium aphanidermatum (Edson) Fitzp, wet rot caused by Fusarium solani (Martius) newlineSaccardo, bacterial wilt caused by Ralstonia solanacearum (Smith) Yabuuchi, Sclerotium rot newlinecaused by Sclerotium rolfsii Saccardo and root knot caused by Meloidogyne arenaria (Neal) newlineChitwood. The individual pathogen can cause rhizome rot or combination of pathogens also newlinecan cause rhizome rot. newlinePythium aphanidermatum was isolated from all the locations collected and found to newlinebe most predominant pathogen. Ralstonia solanacearum was detected only from the southern newlinedistricts of Karnataka i.e., Kodagu, Chikmagalur, Hassan, Mysore, and Sagar. The incidence newlineof rhizome rot of turmeric was meager as compared to ginger. newlineThe inoculum level studies revealed that, increase in per cent inoculum level newlineincreased the per cent disease incidence. In sequential inoculation studies, in case of both newlinethe crops i.e., ginger and turmeric, when first inoculated with Meloidogyne arenaria followed newlineby other pathogens showed maximum disease incidence as compared to individual newlineinoculations. newlineThe results of isozyme analysis of three i.e., peroxidase, polyphenol oxidase and newlinecatalase studied for variability indicated that, there was slight amount of variation. RAPD data newlinedistinguished the twelve isolates into two major clusters A and B. The results revealed that, newlinegeographical locations of isolates were closely related. newlineMaran and Vardha ginger varieties were considered as moderately resistant. CO-1 newlinevariety was considered as moderately resistant. Sowing in March significantly showed less newlinedisease incidence at both the locations of Sirsi and Bidar, which recorded 8.25 and 9.00 per newlinecent respectively. newlineThe field experiment conducted at farmer field revealed that, there was significant newlineincrease in the per cent