Prevalence and impact of Septoria tritici blotch (Septoria tritici) on bread wheat production in Ethiopia

Abstract Ethiopia is the second-largest wheat producer in Sub-Saharan Africa, after South Africa. Despite this, the average wheat grain yield remains low and below the global average. Wheat production and productivity are significantly affected by Septoria tritici blotch (STB), a foliar disease caused by the pathogenic fungus Zymoseptoria tritici . STB is a globally important disease of bread wheat and contributes to substantial yield losses in many wheat-growing regions of Ethiopia. Favorable weather conditions and agronomic factors such as high altitudes, frequent rainfall, moderate temperatures, early planting, vertisol soils, and the nature of the previous crop strongly influence the spread of STB. In the Central Highlands of Ethiopia, Septoria leaf blotch is the most prevalent foliar disease, with incidence ranging from 75 to 100% and severity from 4 to 89%. Major wheat diseases in Ethiopia generally cause yield losses between 50 and 82% in Ethiopia. Most high-yielding wheat cultivars in Ethiopia are susceptible to STB, and a fully resistant variety has yet to be developed. Various disease management strategies are employed to mitigate its effects. While cultural practices, biological agents, fungicide applications, and host resistance are used to manage the disease. However, the effectiveness is often limited by the pathogen’s genetic diversity and changing environmental conditions. Therefore, integrate combined disease management approaches and accelerating the development of resistant wheat varieties are crucial to effectively reducing the impact of STB.