ABSTRACT
Postharvest diseases are one of the major causes of the postharvest losses of fresh fruits and vegetables during transportation as well as storage. Traditionally, synthetic fungicides are primarily used to control postharvest decay loss. However, with the increased public awareness and changing life-style, a shift toward safer and more eco-friendly alternatives for the control of postharvest decays is being observed. Among various biological approaches, the use of antagonistic microorganisms is becoming popular throughout the world. Several postharvest diseases can now be controlled by microbial antagonists. Though the major mechanism(s) of microbial antagonists in suppressing the postharvest diseases is still unknown, competition for nutrients and space could be the most widely accepted mechanism. In addition, production of antibiotics, direct parasitism, and possibly induced resistance in the harvested commodity are other modes of their actions by which they suppress the activity of postharvest pathogens in fruits and vegetables. Microbial antagonists are applied either before or after harvest, but postharvest applications are more effective than pre-harvest applications. Microbial antagonists used in combinations were found to provide better control of postharvest diseases over individual cultures or strains. Similarly, the efficacy of the microbial antagonist(s) can be enhanced if they are used
with low doses of fungicides, salt additives, and physical treatments like hot water dips, irradiation with ultraviolet light, etc. Although the results of this technology are encouraging, we need to continue to explore the potential uses on the commercial scale in different corners of the world. Nonetheless, it is necessary to continue identifying new potential microorganisms, better understanding their mode of action, and pathogen, antagonist and host interactions, to increase the potential of bio-control agents in becoming a real alternative to synthetic postharvest fungicides.
