**4. Causes of postharvest diseases**

In general, postharvest diseases and losses of vegetables are incited by fungi and bacteria. Postharvest diseases are often classified on the basis of the infection as "quiescent"or "latent", where the pathogen infects before harvest in the field. Examples of postharvest diseases arising from quiescent infections include anthracnose of various vegetables caused by *Colletotrichum* spp. and gray mold rot caused by *Botrytis cinerea*. Some pathogens infect vegetables after harvest during storage and transport, which is called postharvest infection e.g. nesting disease of pea caused by *Pythium* species or *Rhizopus* species. Microbes infect horticultural produce and spread rapidly due to a lack of natural defense mechanisms in the tissues of the produce. Management of postharvest spoilage is becoming a very difficult task because the pesticides/chemicals available are rapidly declining with consumer concern for food safety.
