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  • Author or Editor: P. D. Lidster x
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Abstract

Preharvest antitranspirant sprays were most effective in decreasing the incidence of surface pitting in ‘Van’ sweet cherries (Prunus avium L.) when applied immediately prior to harvest. Antitranspirant or wax coatings applied to ‘Van’ cherries as a postharvest dip decreased weight loss in storage, the incidence of discolored stems and surface pitting in storage. Antitranspirant concentration in the postharvest dipping solution was negatively correlated to the incidence of surface pitting.

Open Access
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Storage of `McIntosh' apples (Malus domestica Borkh.) in high humidity (94% to 100% RH) or in 0.5% CO2 plus 1.0% O2 at 3C (LO) atmospheres decreased resistance to ethane diffusion relative to fruit stored in low humidity (75% RH) or in 5.0% CO2 plus 3.0% O2 at 3C (SCA), respectively. Loss of fruit firmness of SCA- or LO-stored `McIntosh' apples, determined immediately after storage or after 7 days at 20C, decreased with increased storage humidity in each of three crop years. Storage humidity did not significantly affect (P = 0.05) fruit titratable acids or soluble solids contents. High storage humidity (96% to 100% RH) generally increased the incidence of senescent disorders (consisting of senescent breakdown and senile brown core) in SCA-stored fruit, while humidities of 92% to 100% RH decreased the incidence of low-O2 injuries (epidermal bluing and cortical browning) in LO-stored fruit. Senescent disorders were found in SCA-stored fruit, but not in LO-stored fruit. The incidence of decay was not significantly affected by either storage humidity or atmosphere.

Free access

Abstract

Applications of an antitranspirant (8% v/v Vapor Gard) to leaves decreased concentrations of N, P, Mg, and Ca in leaves, decreased apple dry-matter content, mass, and the amount of Ca per apple, but increased fruit firmness at harvest and after 120 days of 0°C air storage. Surfactant applications (8% v/v Tween 20) to fruit decreased fruit mass and N and Mg concentrations in leaves, but increased fruit dry-matter content and firmness after storage. Since selective application of either an antitranspirant or a surfactant to leaves or fruit, respectively, to modify the water loss balance between the fruit and leaves did not increase Ca concentrations in fruit, increased fruit firmness was probably due to reduced fruit mass and increased dry-matter contents.

Open Access

Abstract

A delay period of 2 to 6 days at 21°C prior to cold storage of ‘Spartan’ apples (Malus domestica Borkh.) was effective in reducing incidence of breakdown in fruit harvested at 3 maturities. The incidence of decay was higher in immature and overmature fruit than in fruit harvested at optimum maturity. The incidence of core browning was highest in immature fruit and was reduced by a 2 to 6 day delay. Delay in storing fruit was associated with slightly softer fruit at harvest or after 4 months storage, but had no effect on fruit firmness after 7 months storage.

Open Access

Abstract

Exposing ‘Spartan’ or ‘Golden Delicious’ apples (Malus domestica Borkh.) to 38°C for 4 to 6 days immediately after harvest suppressed softening during subsequent storage at −1°C 90 to 94% relative humidity. The rate of acid loss during the period of heating was rapid, but returned to normal during cold storage. Breakdown, core browning, and decay of ‘Spartan’ apple were almost eliminated by the heat treatment. There were no physiological disorders in the ‘Golden Delicious’.

Open Access

Abstract

Gibberellic acid (GA3) sprays applied approximately 4 weeks before harvest reduced postharvest surface marking of ‘Van’ and ‘Lambert’ sweet cherries (Prunus avium L.). Surface pitting was reduced more consistently than was visible bruising. GA3-treated fruits were larger and firmer when harvested at a prescribed color maturity. Mesocarp tissue of treated fruits was higher in alcohol insoluble solids, higher in dry weight and contained less nitrogen per unit of fresh or dry weight. Ethephon applied a few days before harvest reduced fruit removal force but did not consistently reduce the incidence of bruising or surface pitting. ‘Lambert’ fruits picked without stems developed more surface pitting than stemmed fruits. It is proposed that GA3 improves postharvest fruit condition by more than one mechanism. Increased fruit firmness may reduce the tendency to bruise but pitting appears to be suppressed by some other physiological effect of the GA3 treatment.

Open Access
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Abstract

The incidence of surface pitting and bruises in sweet charries (Prunus avium L. cv. Van) increased with distance of free fall. Mature fruit developed less surface pitting but developed more flattened bruises than less mature fruit in response to impact forces. Increased impact force applied to fruit resulted in a decrease in titratable acidity after storage. Fruit firmness and bioyield determined after storage increased to a maximum with the height of free fall of 45 cm for the intermediate fruit maturity only. Fruit contact with rough surfaces resulted in a significantly higher incidence of surface pitting than in fruit damaged by smooth surfaces.

Open Access

Abstract

The mortality of European red mite [Panonychus ulmi (Koch)] eggs on fruit of ‘McIntosh’ apple (Malus domestica Borkh.) in storage increased with continuing exposure to low O2 (1.5% CO2 + 1.0% O2) or conventional controlled atmospheres (5.0% CO2 + 3.0% O2) and with elevated storage temperatures to 7.5°C. Lethality was sufficient to provide commercial control for overwintering populations. Susceptibility of red mite eggs differed among years and orchards within years.

Open Access

Abstract

Reduced O2 storage (3.0 or 1.0%) significantly increased mortality of overwintering apple rust mite (Aculus schlechtendali (Nal.)) and European red mite (Panonychus ulmi (Koch)) egg populations on ‘Mcintosh’ apples (Malus domestica Borkh.). High levels of mortality can be achieved during the usual commercial storage period for apples in 1.0% O2 atmospheres. Addition of CO2 decreased red mite survival at 3% O2 storage.

Open Access

Abstract

An ethyl acetate extract of ground apples (Malus domestica Borkh.) was concentrated and purified for a specific (β-galactosidase inhibitory function. Vacuum infusion of either H2O or the extract restricted initial C2H4 evolution from apples but had no effect on fruit soluble solids and titratable acid levels in apples held at 20°C. Infusion of the extract did not affect the mean CO2 evolution from ‘McIntosh’ apples over a 5-day period but reduced the rate of CO2 evolution over time. Vacuum infusion of the extract containing the (β-galactosidase inhibitor resulted in retention of fruit firmness in ‘McIntosh’ and ‘Gravenstein’ apples held at 20°.

Open Access