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.
