02303nam a2200241 a 450000100080000000500110000800800410001910000240006024501330008426000430021730000100026050000190027052016230028965000120191265000140192465000220193865000120196065000130197265000230198565000250200865000100203365300180204315632071999-04-22       1986    bl uuuu  m   00u1 u    #d1 aLEITE JUNIOR, R. P.  aThe relationship between pathogenic and nonpathogenic strains of Pseudomonas syringae and bacterial brown spot disease in beans.  aMadison: University of Wisconsinc1986  a107p.  aTese Mestrado.  aStudies were conducted to determine the ability of nonpathogenic strains of Pseudomonas syringae pv. syringae to colonize the snap bean phylloplane. The effect of colonization by nonpathogenic P. syringae pv. syringae, was examined under field conditons. Strains of P. syringae nonpathogenic to beans originally obtained from bean leaf surface were introduced into field plots by seed treatment before planting and/or by spray application. Bacterial population sizes on bean leaflets and pods were estimated by dilution plating from bulked samples. The nonpathogenic strains of P. syringae colonized bean leaflets and pods, and reached populations for 10 [elevado a 3] to 10 [elevado a 5]  CFU/ leaflet or pod. However, dry weather was apparently unfavorable for the establishment of the nonpathogenic strains on bean plants. The population sizes of the nonpathogenic strains remined below 10 [elevado a 3] CFU/  leaflet under these conditions. The presence of high epiphytic populations of P. syringae-like bacteria (PSLB) (10 [elevado a 6] CFU/leaflet) on bean plants, apparently prevented the establishment of large epiphytic populations (10 [elevado a 3] CFU/leaflet) of the nonpathogenic strains of P. syringae. The nonpathogenic strains failed to reduce the occurrence of bacterial brown spot, in these cases. Decreased number of naturally occurring were observed on tretments sprayed with PSLB nonpathogenic strains were applied prior to establishment of high populations of PSLB. Significant reductions (p&lt.05) in bacterial brown spot severity on leaflets and inicidence on pods occurred in these treatments.  aprogeny  aBactéria  aDoença de Planta  aFeijão  aLinhagem  aPhaseolus Vulgaris  aPseudomonas Syringae  aRaça  aPlant disease