Evaluation of management methods and host resistance for controlling garlic white rot (Sclerotium cepivorum) disease in North Shewa, central Ethiopia

The field experiments were carried out in 2021/22 and 2022/23 main cropping seasons to evaluate the effectiveness of management methods and host resistance in reducing white rot disease epidemics. The experiment was arranged in a randomized complete block design with three replications. The trials were conducted in naturally infested fields of S. cepivorum due to repeated cultivation of allium species in the previous cropping seasons. The research conducted over two-season results that fungicide significantly reduced the intensity of white rot disease, leading to increased garlic yield. A highly significant (P<0.001) difference between treatments has observed in the intensity of disease measured on harvested bulbs with severity ranging from 11.27 % to 53.46 % in 2021/22 and 10.63 % to 72.88 % in 2022/23 cropping seasons. The marketable yield and total yield ton/ha were significantly (p<0.001) affected by the main effect of year, variety, chemical and the interaction effect of variety with chemical. From the average yield of both seasons, Tseday variety treated with (clove plus basal) achieved the highest (4.31 ton ha−1) yield followed by Bishoftu (4.27ton ha−1), Thus, these experiments showed that Apron® Star 42WS as a clove treatment supplemented with a basal spray of Ridomil Gold® MZ 68 WG fungicides were the most important chemical control options in reducing the epidemics of diseases and also enhanced the variety's performances as compared to other treatments. Therefore, this research finding can be an immediate solution for garlic growers in the study area and other similar agro-ecologies in Ethiopia. However, further extensive studies are recommended for screening garlic germplasms for resistance against Sclerotium cepivorum and different management options including biological methods under different agro-ecological conditions to come up with suitable management options to increase garlic production in Ethiopia.