Effect of time of inoculation with Xanthomonas campestris pv. mangiferaeindicae on mango fruits susceptibility. Epiphytic survival of X. c. pv. mangiferaeindicae on mango fruits in relation to disease development.
Pruvost O., Luisetti J.
Author Affiliation: Centre de Coopération Internationale en Recherche Agronomique pour le Développement, Département Fruitier (IRFA), Laboratoire de Phytopathologie, BP 180, 97455 Saint Pierre, Réunion.
Journal of Phytopathology 133 : 139-151
Abstract : Results of field inoculations showed that susceptibility of mango fruits to bacterial black spot disease was related to the stage of fruit development and to climatic factors, the highest percentage of infected fruits occurring when inoculations were performed during the month just before harvest, a period in which rain fell and the av. temp. was c. 25°C. Wounds and lenticels were effective entry sites for the bacterium. The ability of lenticels to take up bacterial inoculum was estimated using a safranin assay, and was found to be directly related to fruit age. The pathogen could survive epiphytically on immature mango fruits, bacterial populations of c. 105 c.f.u./fruit being common. Epiphytic populations were not detected on symptomless mature fruits. The number of bacterial spots occurring on mature fruits was directly related to epiphytic populations, suggesting that the resident populations are an important source of inoculum for fruit infection.