The Application Of Biocontrol In Controling Postharvest Diseases

Postharvest diseases caused by pathogenic fungi result in great losses in fruits and vegetables. Synthetic fungicides which are generally applied as a main method to control postharvest diseases are followed by problems like food safety and the environment pollution. As a result , biological control has been advanced as an alternative to synthetic fungicides for its characters of less potentially harmful to health and the environment. The antagonists were isolated from the surface of apples and citrus. Three isolates of yeast and one isolate of bacterium were obtained. Among them, Trichosporon pullulans had never been reported as an antagonist used in the field of postharvest biocontrol. The biocontrol efficacy, population dynamic and effects of calcium chloride and nutritional material on biocontrol activity of antagonist were mainly studied. Several results were attained. The bacterium antagonist was effective in controling decay of citrus caused by Penicillium digitatum. Three isolates of yeast antagonist were effective in controling decay of apple caused by Penicillium expansum, which can be enhanced by 2%CaCl2. Cryptococcus laurentii Skinner was effective for the controling of grape decay caused by wound. Some nutritional materials can improve its efficacy.