Control: Post-Harvest Pathogens

Storage of sound high-quantity horticultural produce curtails its exposure to air and soil-borne pathogens in the outdoor environment and should therefore reduce losses. Pathogens present as latent infections on produce going into storage and more frequently new infections from air-borne pathogens present within a store will cause disease on crops as they are stored. Disease development is encouraged by biochemical and physiological changes which begin once crops are harvested. A primary aim of storage should be to limit such changes for as long as possible. Clamps and barn types of storage provide cool conditions for preserving commodities such as cabbage, carrots, celery, onions and potatoes. The economic margins to be gained by storage are often such as to permit the use of more sophisticated techniques, rather than these traditional methods, whereby losses due to pathogens may be reduced. Storage may be short-term—a few days—as for soft fruit and loose leafy vegetables in order to remove field heat, thereby delaying the onset of wilting and disease and permitting transit over long distances; this is achieved by vacuum, forced air, hydro or ice-bank cooling. Storage may be long-term—up to several months—by means of refrigeration or controlled atmospheres.