The current research conducted to determine the impact of wheat varieties, sowing dates and fungicide spray frequencies on disease development and wheat yield. Two bread wheat varieties, three sowing dates and four fungicide frequencies were evaluated in a factorial RCBD design at Holetta Agricultural Research center during 2020 and 2021 cropping seasons. The highest AUDPC values were recorded in Pavon-76 variety of unsprayed plots at early sowing dates (2502.5 %-days) and (1940.3 %-days) in 2020 and 2021 cropping seasons respectively. The lowest AUDPC (276.3 %-days) value was recorded on the Alidoro variety at late sowing dates with three times fungicide spray frequencies. Highest grain yields were recorded on Alidoro variety (7.1t/ha) with three times spray frequencies during late-sowing date. The highest net benefit (245,095.5 ETB) and the lowest net benefit (29,463ETB) were obtained from two times sprayed and unsprayed plots during late and early sowing date planted with Alidoro and pavon-76 varieties, respectively. The present findings confirmed that spray frequencies with appropriate sowing dates play an-important role in managing the disease on partially resistant varieties. We have recommended that late sowing date with 3 times spray frequencies of systemic fungicides are very economical to manage ZSTB disease on susceptible wheat variety and increased grain yield and yield components.
