Phosphite for the root rot (Rhizoctonia solani) management in common bean and compatibility with Rhizobium tropici

ABSTRACT

Phosphites can be considered an additional strategy to be included in disease management programs. Therefore, this study aims to evaluate the application of potassium phosphite (KPhi) in common bean seeds, in the reduction of intensity of root rot (Rhizoctonia solani) and in the compatibility with Rhizobium tropici, a nitrogen-fixing bacterium. The emergence speed index (ESI) and the percentage of total emergence were evaluated in seeds inoculated with R. solani and treated with KPhi. The number of nodules per root system, dry nodule mass, quantified the compatibility Phi x R. tropici, dry mass, nitrogen content, and nitrogen accumulation in the shoots. KPhi promoted a higher ESI and increase in plant stand compared to the control treatment. The number of nodules formed and the nitrogen content and accumulation in the KPhi treatments were similar to control (seeds inoculated with R. tropici). Thus, the treatment of seeds with KPhi provides control of R. solani and is compatible with R. tropici.

Key words Phaseolus vulgaris L.; emergence speed index; seeds