Integrated control of Penicillium expansum and Botrytis cinerea of apples using potassium silicate, yeast antagonists and YieldPlus^®

The use of potassium silicate (K₂SiO₃), YieldPlus^® and yeast antagonists treatments, alone or in combination, was investigated for the control of gray and blue molds of 'Golden Delicious' apples. In vitro studies indicated that yeast isolates YP25 and YP60 were compatible with K₂SiO₃ postharvest treatments. K₂SiO₃ alone or in combination with yeast antagonists and YieldPlus^® reduced postharvest gray and blue molds on apples. YieldPlus^® and Imazalil^® treatments alone were more effective in reducing gray and blue molds than yeast isolates YP25 and YP60. The combination of K₂SiO₃ with an antagonist mixture of YP25+YP60 provided the best control (95%) of gray mold, while the combination of K₂SiO₃ and YieldPlus^® provided the best control (85%) of blue mold. The use of potassium silicate and yeasts antagonists in combination resulted in 95 and 77.5% control of B. cinerea and P. expansum, respectively, in 'Golden Delicious' apples compared to 62.5 and 65% on Imazalil^® fungicide treated fruits.