Diseases of Vegetable, Ornamental and Spice Crops

Lecture 32

Introduction:

Post-harvest loss has been defined as “that weight of wholesome edible product that is normally consumed by humans and that has been separated from the medium and the sites of its immediate growth or production by deliberate human action with the intension of using it for human feeding but which for any reason fails to be consumed by humans”. Not only quantity and quality, but even appearance of vegetables and ornamentals may be affected and their market value is reduced. In addition to losses in terms of food value, post-harvest loss also be apportioned into looses at various stages, viz. storage loss, transportation loss and loss at the level of wholesaler, retailer or consumer. Losses at the wholesaler or retailer are sometimes referred to as ‘shrink’. Such data would provide a post-harvest crop loss profile.

The quantum of loss varies between and within countries as well as due to time lag between surveys. Increasing degree of mechanization in agriculture has sometimes caused increase in loss. Mechanically harvested produce succumbs more to decay loss than the traditionally harvested produce. In developing and under developing countries the losses are more due to lack of adequate and proper storage and transport facilities than anything else.

Among the different perishable commodities, vegetables, flowers and spices are of prime importance due to their large size, soft texture, high water content and respiration, which make them very prone to deterioration after harvest. In addition to various non-parasite causes (disorders), fungi, and bacteria and in some cases viruses are responsible for post-harvest rots of vegetables.