The inhibitory effect of yeast Pichia membranaefaciens on black spot decay of postharvest broccoli, caused by Alternaria alternata (Fr.) Keissler, was investigated and possiblemechanisms were explored in both in vitro and in vivo experiments. There was a positive correlation between the concentration of yeast cells and reduction of hyphal growth or spore germination from 1×104 to 1×108 cells/…