Preharvest Factors Influencing Postharvest Quality of Tropical and Subtropical Fruit

Climate/environment Rootstock/scion Planting design Pruning practices Pest management Irrigation Plant growth regulators Plant nutrition The goal for postharvest physiologists, whether they are working in basic or applied research, is to maximize the postharvest quality of horticultural commodities. Quality relates to several factors that can be commodity specific and mean different things to different people. The consumer may perceive quality as it relates to appearance, flavor, and dollar value. The packinghouse handler, wholesale distributor, and retailer, in contrast, may perceive quality as ease of handling, uniformity of packaging, and freedom from physical and physiological defects as well as pathological breakdown. Although there is much to learn about the mechanisms of a given tropical or subtropical fruit’s response to the postharvest environment, past research has provided handlers with the general principles of sound commodity management. These principles include temperature, relative humidity, atmosphere modification, cooling, and judicious use of fungicides and waxes following harvest. These management strategies are of critical importance for tropical products given their long transit conditions and the potential need for postharvest insect disinfestation quarantine treatments. This paper will examine the role of the preharvest environment and how it may affect the postharvest life of tropical and subtropical fruit. Essentially, preharvest factors can influence both the rate of fruit development and maturation. The preharvest environment can also have a physical impact on fruit quality: for example, wind or insect scarring may reduce the packout percentage. Finally and most important, but much more difficult to quantify, are those effects that influence susceptibility to physiological and pathological breakdown. This review will not dwell on the latter, but recognizes that the influence of preharvest factors on postharvest decay incidence and severity has been well documented. One must remember that the plant exists in a dynamic environment and therefore can respond to changes to that environment in an interactive fashion. The factors listed in Table 1 are neither all inclusive nor mutually exclusive. Several examples will illustrate the interaction between one or more preharvest factors on postharvest fruit quality.