Faba bean chocolate spot and factors affecting disease intensity in major faba bean growing districts of North Shewa, central highlands of Ethiopia

Faba bean is an important legume consumed as a source of food and used as a cash crop worldwide. However, its productivity is constrained by several biotic and abiotic factors among which chocolate spot caused by the fungus Botrytis fabae is the most important. A field survey was conducted to determine the incidence and severity of chocolate spot and association of factors influencing faba bean chocolate spot epidemics in major faba bean growing areas of central highlands of Ethiopia, during 2021 and 2022. The survey was conducted in a total of 218 fields from five districts within north Shewa zone. Variables such as district, altitude, weed management, sowing date, cropping season and growth stage were very strongly associated with chocolate spot severity and incidence, when entered into the logistic regression model as a single variable. In the districts of Angolelana Tera and Saya Debrna Wayu, there was a strong correlation observed between high severity (> 20%) and incidence (> 30%) of chocolate spot and certain factors. These factors included lower altitude, lack of weeding, exclusive cropping, late sowing dates, the flowering growth stage, high plant density, and the 2022 cropping season. The study indicated that faba bean chocolate spot was found a major production constraint in all survey districts. Absolutely, to effectively manage the disease, it is crucial to focus on several key areas including choosing the right altitude, implementing effective weed management strategies, adjusting the density of the crop, and determining the most suitable sowing dates.