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 work in basic or applied research, is to maximize the postharvest quali horticultural commodities. Quality relates to several factors that ca commodity specific and mean different things to different people. T consumer may perceive quality as it relates to appearance, flavor dollar value. The packinghouse handler, wholesale distributor, retailer, in contrast, may perceive quality as ease of handling, un mity of packaging, and freedom from physical and physiologi defects as well as pathological breakdown. Although there is muc learn about the mechanisms of a given tropical or subtropical fru response to the postharvest environment, past research has pro handlers with the general principles of sound commodity mana ment. These principles include temperature, relative humidity, at sphere modification, cooling, and judicious use of fungicides a waxes following harvest. These management strategies are of cr importance for tropical products given their long transit conditions a the potential need for postharvest insect disinfestation quaran treatments. This paper will examine the role of the preharvest environment how it may affect the postharvest life of tropical and subtropical fr Essentially, preharvest factors can influence both the rate of development and maturation. The preharvest environment can have a physical impact on fruit quality: for example, wind or ins scarring may reduce the packout percentage. Finally and most im tant, but much more difficult to quantify, are those effects t influence susceptibility to physiological and pathological breakdow This review will not dwell on the latter, but recognizes that t influence of preharvest factors on postharvest decay incidence severity has been well documented. One must remember that the plant exists in a dynamic environm and therefore can respond to changes to that environment i interactive fashion. The factors listed in Table 1 are neither inclusive nor mutually exclusive. Several examples will illustrate interaction between one or more preharvest factors on postharves quality.
Orchard application of paclobutrazol on ripening, quality and storage of mango fruits
Abstract Paclobutrazol (PP 333) was applied as foliar spray at 250, 500, 1000, 2000 or 3000 mg l −1 on 15 October 1987 followed by another spray 20 days before harvest (13 May 1988) in ‘Dashehari’ mango ( Mangifera indica L.) trees. The effect was more pronounced in fruits that received 2000 or 3000 mg l −1 than lower doses. These treatments attained better quality as judged from the total soluble solids, total acidity, ascorbic acid content, total chlorophyll, total carotenoids, amylase and peroxidase activity from harvest to 12 days of storage at ambient conditions.
Effect of Paclobutrazol and Analogs on Growth, Yield, Fruit Quality, and Storage Potential of ‘Delicious’ Apples

A postbloom foliar application of 1500 and 3000 ppm paclobutrazol (PB) increased flesh firmness of ‘Delicious’ apple (Malus domestica Borkh.) but reduced seed number and fruit size at harvest. The following year, flowering was not affected, but fruit set was increased. A decrease in terminal growth, leaf size, fruit L/D ratio, fruit size, pedicel length, and fruit soluble solids were also observed with the high rate of PB. PB increased fruit flesh calcium and total yield, and retarded fruit ripening. Dichlorobutrazol (DCB) did not affect final terminal growth but reduced L/D ratio, pedicel length, and fruit size the year after application. Following storage, flesh firmness of PBtreated fruit was not influenced, but senescent breakdown was dramatically reduced. Retarded ripening and reduced senescent breakdown were attributed to increased calcium in fruit flesh. Variability in terminal growth was increased as the inhibitory effects of PB dissipated. Three years after application, fruit L/D ratio and pedicel length were decreased, even though there was no longer a reduction in terminal growth. Chemical names used: (2RS, 3RS)-1-(2,2-dichlorophenyl-4-4-dimethyl-2-(1H,1,2,4-triazol-lyl)pentan-3-ol (paclobutrazol); (2 RS, 3 RS)-1-2,2-dichlorophenyl-4,4-dimethyl-2-(1H1,2,4-triazol-lyl)pentan-3-ol (dichlorobutrazol).