Sowing, field size, and soil characteristics affect bean-Fusarium-wilt pathosystems

Fusarium wilt is an important disease threatening bean production in Zanjan, Iran. Interactions between agrosystem characteristics, bean-wilt, and soil are still poorly understood. In this study, effects of several cropping and soil characteristics on Fusarium wilt were analyzed in 48 bean growers' fields. Application of urea and herbicides, bean market class, preceding crop and sampling year had no significant effect on disease parameters (area under disease progress curve, average disease index over sampling period, disease index, and infection rate) in most cases. Fusarium-wilt-index at pod maturity stage of bean growth was selected for regression analysis as dependent variable. A statistical analysis based on principal components regression showed that soil pH, sowing depth, soil silt, sowing date, and field size explained 68% of variation in Fusarium wilt index observed in bean crops. Findings suggest postponing sowing beans at shallow depths in appropriate soil texture with neutral pH as potential strategies to manage Fusarium wilt.