Damage by Xanthomonas campestris pv. phaseoli and bean yield

Abstract

Common bacterial blight produced by Xanthomonas campestris pv. phaseoli (Xcp), is considered one of the diseases of major economic importance in bean (Phaseolus vulgaris) production in Honduras. Yield reduction at farm level produced by this pathogen is considered significant; however, its magnitude is unknown. To determine the severity, incidence and percentage of seed yield reduction caused by Xcp, two experiments were conducted in El Zamorano Valley, Honduras, during the early (June to Aug.) and late (Sept. to Dec.) growing seasons of 1989. Three genotypes differing ¡n their reaction to Xcp, XAN 155 (resistant), EAP 10-88 (moderately resistant) and "Catrachita" (susceptible), were evaluated under protected and unprotected treatments applied to plants artificially inoculated with Xcp. Reaction to Xcp clearly reflected the degree of resistance of each genotype. Yield losses caused by Xcp during the late season ranged between 22 and 41.6% in the unprotected treatment. The severity of Xcp observed in the resistant genotype XAN 155 suggested that at farm level the implementation of an integrated control program is necessary in order to reduce yield losses caused by this pathogen.