Effects of Trichosporon sp in combination with calcium and fungicide on biocontrol of postharvest diseases in apple fruits

The capability of yeast Trichosporon sp., an antagonist isolated from peach fruit, in biological control was evaluated in apple (Malus domestica Borkh. cv. Fuji) fruits, when inoculated with different concentrations of Botrytis cinerea Pers. and Penicillium expansum (Link) Thom, as well as in combination with calcium and fungicide. The concentrations of the yeast cells and pathogen spores obviously influenced disease incidence and lesion development in apples. There was a significant negative correlation between concentrations of the yeast cells and infectivity of the pathogens. When the yeast cell suspensions reached the concentration of 10(8) colony-forming units (CFU) /mL, there was no infection caused by B. cinerea and P. expansum with spore concentrations below 10(6) spores/mL, in apple fruits. The yeast at concentrations of 10(6) - 10(7) CFU/mL in combination with fungicide (iprodione at 50 muL/L) provided control of decay caused by B. cinerea and P. expansum better than separate application. Effect of controlling. gray mould and blue mould rots was enhanced when Trichosporon sp., even at low concentration of 10(5) CFU/mL, was applied in the presence of 1% -2% CaCl2 in an aqueous suspension.