Management of garlic white rot (Stromatinia cepivora) with fungicides and host resistance in North Shewa, central highland of Ethiopia

Garlic is one of the most popular spices in the world and the second most widely cultivated Allium species next to the onion. Garlic production is reduced due to many biotic and abiotic factors, among which white rot disease caused by Stromatinia cepivora (Berk.) Whetzel causes severe yield losses. The study was conducted to evaluate the combined effects of chemical fungicides and garlic varieties on the epidemic development of white rot disease. The experiment was conducted at Chefanen Kebele using three garlic varieties and three chemicals during the 2019 and 2020 seasons. The experimental design was a randomized complete block with three replicates. The application of Apron Star 42, a commercial fungicide containing Thiametoxam 20%, Metalaxyl-M 20% and Difenconazole 2%, significantly reduced the white rot disease on all varieties as compared to the untreated local variety. Bishoftu Nech and MM-98 varieties exhibited fast emergence as compared to the local variety, consequently increasing the yield and yield components of garlic. The application of Apron Star 42, significantly increased yield parameters compared to the untreated control. The significant effect and the negative correlations of days to maturity, growth parameters, yield, and yield components with disease parameters indicated that the white rot disease had a very crucial impact on garlic yield. Application of Apron Star 42 to improved garlic varieties is recommended to reduce the severity of white rot infections and to increase garlic production in the study area.