DISTRIBUTION AND MANAGEMENT OF WHITE-ROT (Sclerotium cepivorum B.) DISEASE OF GARLIC (Allium sativum L.) VARIETIES IN NORTH EAST SHEWA, CENTRAL ETHIOPIA

Abstract

Garlic production is constrained by rust, downy mildew, basal-rot, botrytis-rot, penicillium decay, white-rot and namatodes. Among these, white-rot fungal disease caused by Sclerotium cepivorum B. is a major production threat of garlic in Ethiopia. The study was conducted to assess the distribution of garlic white-rot disease and to evaluate the combined effects of fungicides and varieties on the epidemic of white-rot disease and the corresponding yield and yield components of garlic. The survey was made in four districts of the North Showa zone (Angolelanatera, Basonaworana, Tarmaber, and Mojanawodera). It was made to understand the distribution and management status of the disease; 94.78 % of the garlic producers observed the distribution of the disease on their garlic fields. The majority (57.5 %) of the garlic producers got poor productivity of garlic. Along with this, a field experiment was conducted; the treatments were laid out in a factorial arrangement with three replications using randomized complete block design (RCBD). The findings showed that varieties, fungicide types and the interaction significantly affected the disease parameters. Improved varieties increased emergence rate (Bishoftu nech by 4.12 and MM 98 by 2.11days) and prolonged maturity time by 7 days as compared to the local variety. MM-98 and Bishoftu nech varieties treated by Apron star 42 WS fungicide showed the lowest PSI, followed by the MM-98 and Bishoftu nech varieties treated by More 720 fungicide as compared with the untreated local variety. The untreated plots showed a high area under disease progress curve than the treated once. MM-98 and Bishoftu nech varieties increased the total yield by 111% (6.81 tha-1 ) and 95% (6.28 tha-1 ) as compared to the local variety (3.22 tha-1 ), respectively; and also Apron star 42 WS treated increased the total yield by 85.85 % (7.88 tha-1 ) as compared to untreated (4.24 tha-1 ). The application of fungicides along improved varieties for the disease management was found profitable. Hence, it could be concluded the field survey indicated that the occurrence of white-rot disease in the garlic field and productivity were different among districts and Apron star 42 WS treated and MM-98 and Bishoftu nech varieties had resulted in a lower disease incidence at 90 DAP, severity at 90 and 97 DAP and AUDPC with highest bulb weight, total dry biomass and yield per hectare.