Association of Cultural and Environmental Factors with the Newly Emerged Faba Bean Gall (Physoderma viciae) Disease Intensity in Tigary, Northern Ethiopia

Faba bean is a multipurpose crop which plays a vital role, in human nutrition and animal feed, and helpful for improving soil fertility. However, currently its production and productivity has been treated by biotic and abiotic factors. One of the main challenges for faba bean production in Tigray is the faba bean gall a new disease caused by (Physoderma viciae). A total crop loss may occur under favorable season for the disease development. The objectives of this study were to map the distribution and quantify the prevalence and severity of faba bean gall disease in major faba bean growing districts of Tigary highlands; to determine the association of factors that contribute to disease severity. Assessment of the disease were done in five districts of south east and east Tigray highlands namely Atsbi, D/tembien, G/afeshum, K/awlaelo and S/tsedaemba in the main cropping season between 15 August to 5 September in 2015. A total of 74 Global Positioning System (GPS) based ground data/ fields were collected and inspected. Survey results shown that, faba bean gall was found widely distributed in all faba bean growing districts. Altitudes, planting times, agronomic practices, soil drainage conditions, and crop growth stage and soil types affected the distribution and intensity of the disease. Highest faba bean gall disease prevalence was observed at Deuatembien (100%), at Atsbi (93.75%) and at G/afeshum (60%) compared to other surveyed districts. Varied level of faba bean gall distribution and severity were found at different faba bean growing districts. Severity with values of 53.33% and 46 % were high in D/tembien and Atsbi distrcts compared to severity of value of 14.83% and 26.1% in S/tsemba and G/afeshum districts, respectively. High faba bean gall disease severity was associated with June planted and at D/tembien district. Therefore, further independent research on effect of planting time is needed to verify and use the cultural practices as an integral component of faba bean gall management in study area and elsewhere with similar agro-ecological settings. Information obtained on the distribution, severity, prevalence, association of cultural and environmental factors with disease intensity is paramount to give clue to develop effective management strategies in the study area and elsewhere with similar agro-ecological settings. It also serves as a baseline information to conduct further detail investigation on faba bean gall disease across the region.