Influences of Antagonist Population Levels, Blossom Development Stage, and Canopy Temperature on the Inhibition ofSclerotinia sclerotiorumon Dry Edible Bean byErwinia herbicola

Abstract

Three strains of Erwinia herbicola, applied to blossoms of dry edible bean (Phaseolus vulgaris) prior to inoculation with ascospores of Sclerotinia sclerotiorum, inhibited ascospore germination and subsequent development of white mold lesions in a bioassay. Although the strains exhibited similar multiplication rates on blossoms, increasing from initial levels of 10 7 cfu per blossom within 16 h at 25 C, they were effective in inhibiting S. sclerotiorum after different periods of multiplication and at different population levels. Strain BI required incubation for at least 24 h, whereas strains B346 and B367 were inhibitory after only 6 h of incubation when population levels were <10 5 cfu per blossom [...]