Modified bean pod assay to detect strains of Pseudomonas syringae pv. syringae that cause bacterial brown spot of snap bean

Consistent results were obtained with a procedure that involves placing a smear of bacterial cells on the pod surface and inserting an insect-mounting pin through the cells and laterally underneath the epidermis of greenhouse-grown snap bean pods (cultivar Bush Blue Lake 274). Since the procedure does not require calculated inoculum concentrations, it is useful in evaluating large numbers of strains (e.g. epiphyte collections) for their ability to cause BBS. Pod assays were more rapid and reliable than leaf assays of whole plants in distinguishing strains of P. v. pv. syringae capable of causing BBS