Biological Control of Postharvest Diseases of Fruits and Vegetables: Recent Advances

Abstract

Although it is difficult to determine the full extent of postharvest losses due to diseases, conservative estimates place losses to fruits and vegetables from spoilage at ≈24% of the harvested crop in the United States (U.S. Dept. of Agriculture, 1965) and 50% in underdeveloped, tropical countries (Coursey and Booth, 1972). Fungicides are a primary means of controlling postharvest diseases (Eckert and Ogawa, 1985). Their use worldwide is variable, comprising 26% of the pesticide market in Europe and Asia and 6% in the United States (Jutsum, 1988). However, as harvested fruits and vegetables are commonly treated with fungicides to retard postharvest diseases, there is a greater likelihood of direct, human exposure to them than to other pesticides that are applied solely to protect foliage. Public and scientific concern about the presence of synthetic chemicals in our food supply and in the environment has been increasing in the past decade. A report from the National Academy of Sciences (NAS) (1987) indicated particular concern about the health risks associated with the use of fungicides. As a direct result of these mounting concerns, real or perceived, several fungicides (e.g., captan and benomyl) have been banned by the U.S. Environmental Protection Agency or voluntarily withdrawn from the market for some or all postharvest use. This action has the potential of greatly diminishing our ability to control postharvest diseases of many commodities. The NAS report clearly indicated this possibility by stating, “For certain crops in certain regions, the loss of all oncogenic compounds-particularly fungicides-would cause severe short-term adjustments in pest control practices because of the lack of economically viable alternatives.” Despite this situation, the trend to restrict or ban the use of current, synthetic fungicides for postharvest use is continuing. A recent report in Postharvest News and Information (Rendall-Dunn, 1991) indicated that the European Parliament has voted in favor of a total ban on postharvest treatment of