Spatial and temporal distribution of faba bean gall (Physoderma) disease and its association with biophysical factors in Ethiopia

Productivity of faba bean is highly constrained by an emerging and destructive faba bean gall (FBG) disease caused by the fungus Physoderma. Field surveys were conducted to assess the spatial and temporal distribution as well as intensity of FBG disease and determine the association of biophysical factors with FBG disease epidemics in Ethiopia, during 2018 and 2019. A total of 783 fields were assessed across 14 districts. FBG disease was present in all surveyed districts with variable incidence and severity. The highest mean FBG disease severity was recorded in Sinan district (64%) and Ankober district (45%) during 2018 and 2019, respectively. The associations of independent variables with disease incidence and severity were analyzed using the logistic regression model. District, altitude (≥2700 m), poorly drained soil, high weed and crop density, flowering stage, manure application, and early or late planting showed a significant association (P < 0.0001) with FBG disease incidence and severity. FBG disease was found as a major production constraint in all survey districts. Therefore, proper soil drainage, weed managements, adjusting crop density, recommended planting time along with tolerant varieties should be targeted.