Management of Septoria Tritici Blotch (Septoria tritici) of Bread Wheat (Triticum aestivum L.) in the Central Highlands of Ethiopia

Septoria tritici blotch (STB) is an economically important foliar disease in the major wheat-growing areas of Ethiopia. The current research was conducted to determine the impact of wheat varieties and fungicides on disease development and wheat yield. Besides, the effect of bread wheat varieties and fungicides on STB development, wheat yield was evaluated at Holleta and Kulumsa in a factorial field experiment involving three bread wheat varieties and six fungicide spray schedules. At Holetta, variety Kekeba had the highest AUDPC (2548) value followed by Madawalabu and Alidoro; whereas at Kulumsa the highest AUDPC (1509) was recorded on variety Madawalabu followed by Alidoro and Kekeba varieties. STB incidence and severity were significantly reduced by the application of fungicides across varieties but fungicide-variety combinations had differential effects on disease development. Wheat grain yields were the lowest from unsprayed plots regardless of variety and location. Kekeba variety treated with Mancozeb-Tilt-Mancozeb-Tilt (MTMT) fungicide combination produced the highest yield (5.05t/ha). The highest (577.31%) and lowest (-19.95%) marginal rate of return were obtained from Tilt and MTMT sprayed fields at Holetta planted with Kekeba and Madawalabu varieties, respectively. On the other hand, at Kulumsa, the highest marginal rate of return (886.88%) and the lowest marginal rate of return (-63.98%) was obtained from Tilt and Mancozeb sprays on Madawalabu and Alidoro varieties, respectively. The present findings confirmed the importance of STB in Ethiopia and the role fungicides play in managing the disease on partially resistant varieties.