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.
Survey of fruit mineral concentrations and postharvest quality of New Zealand‐grown ‘Hass’ avocado (Persea americana Mill.)
Abstract New Zealand ‘Hass’ avocado (Persea americana Mill.) orchards were surveyed to determine if an imbalance in fruit mineral concentrations (Calcium (Ca), Magnesium (Mg), and Potassium (K)) was associated with poor fruit quality. Ranges for average fruit mineral concentrations on surveyed orchards were: Ca, 25–47 mg/100 g dry weight (DW); Mg, 91–113 mg/ 100 g DW; and K, 1126–1608 mg/100 g DW. Fruit with low Ca concentrations had more vascular browning and flesh browning than fruit with high Ca concentrations. Also, fruit Ca concentrations were lower and the incidence of vascular browning higher in fruit that were more mature at harvest. Fruit harvested below the minimum maturity standard (26% DW) had practically no postharvest rots. If harvested above this standard, 12–38% of ripe fruit had severe rots. A new disorder “anthocyanin staining” was observed in the flesh of several fruit. Results are discussed in relation to industry options for predicting and managing fruit quality.
Density of Stomata and Oil Glands and Incidence of Water Spot in the Rind of Washington Navel Orange
1. The mean stomatal density for Washington Navel orange fruits was 13.86 per square millimeter. Stomatal density was greater in small oranges than in large. The mean density of oil glands was 2.33 per square millimeter. 2. Oil glands were more densely distributed in small oranges than in large. Neither the density of the stomata nor the density of the oil glands is related to the incidence of water spot. 3. The radial arrangement of stomata in narrow circular zones about oil glands, as reported by previous investigators for leaves of citrus, was also found in the rind of the Washington Navel orange fruits.