Enhancement of biocontrol activity of yeasts by adding sodium bicarbonate or ammonium molybdate to control postharvest disease of jujube fruits.

Abstract

To assess the potential of sodium bicarbonate and ammonium molybdate as additives in enhancing the biocontrol efficacy of Rhodotorula glutinis and Cryptococcus laurentii against blue mould in jujube fruits. Two yeasts at a concentration of 107 CFU ml-1, in combination with 238 mmol l-1 sodium bicarbonate or 15 mmol l-1 ammonium molybdate, showed a significant inhibition effect on blue mould of jujube fruits stored at 20 degrees C for 5 days. The colonizing ability of the yeasts in wounded sites was significantly decreased in the presence of ammonium molybdate. Combining R. glutinis or C. laurentii with sodium bicarbonate or ammonium molybdate provided a more effective control of postharvest disease than using the antagonistic yeasts or the chemicals alone. The addition of sodium bicarbonate or ammonium molybdate reduced the number of antagonists required to efficiently control disease of postharvest fruits, which could result in the reduction of costs.