Epidemiology of chocolate spot (Botrytis fabae Sard.) on faba bean (Vicia faba L.) in the Highlands of Bale, Sinana district, Southeastern Ethiopia


Dagne Kora Temam Hussein Seid Ahmed

Field experiment was conducted at Sinana Agricultural Research Center in the 2014 main cropping season with the objectives of quantifying the severity of chocolate spot and to assess the effects of the chocolate spot epidemics on faba bean varieties. The treatments included four faba bean varieties (Local, Shalo, Mosisa and Walki) with four fungicide spray schedules (no spray, spray every 7 days, every 14 days and every 21 days) of the contact fungicide Mancozeb at the rate of 2.5 kg ha- . 1 The treatments were arranged in 4 x 4 factorial combinations in randomized complete block design (RCBD) with three replications. Interaction of varieties with fungicides showed significant (P≤0.05) difference in reducing chocolate spot percent severity index. The terminal chocolate spot severity did not exceed 61 % on the susceptible variety (local).The percent severity index of 54, 46 and 44% were recorded on the varities Walki, Shalo and Mosisa, respectively. The maximum AUDPC was calculated on the unsprayed plots of local variety and Walki, which were 1817 %-days and 1716.42 %- days respectively. The chocolate spot was increasing at a rate of 0.03 units per day in unsprayed plots of the local variety and at 0.019 units per day on the variety Walki. There was a possibility of chocolate spot disease management by short spray intervals using Mancozeb fungicide combined with moderately resistant cultivars under southeastern conditions of Ethiopia.


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