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  • Author or Editor: J.C. Morris x
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Abstract

The softening rates of ‘Rome’ apples (Malus domestica Borkh.) from 10 West Virginia orchards stored at two temperatures were compared in 1974, 1976, and 1978. The rate of softening at 20°C declined with time after harvest, and delaying harvest reduced the rate of softening at 20° but had little effect on softening at 0°. Site had little effect on rate of softening. In two of the three years, the rate of softening at 0° was found to be correlated with firmness at harvest and softening at 20°. Regression analysis provided formulas that can be used to predict softening rate in refrigerated air storage at 0° from firmness data at harvest.

Open Access

Three types of soil were mixed with water containing DPA (2000 mg·liter-1) and benomyl (300 mg·liter-1) at 1% to 5% (w/w). `Rome' apples (Malus domestica Borkh.) were dipped in the mixtures over 8 days. The efficiency of DPA as a scald inhibitor was not consistently affected by soil type, soil concentration, or age of mixture. Chemical names used: methyl[1-[(butylamino)carbonyl]-1 H-benzimidazol-2-yl]carbamate (benomyl); diphenldyamine (DPA).

Free access

In most broccoli (Brassica oleracea L. var. italica) cultivars studied, the loss of chlorophyll was marginal after 5 weeks cool storage (1 °C) + 2 days at 20 °C, but there was significant loss of chlorophyll from some poor-storing cultivars, particularly after 10 weeks cool storage (+2 days at 20 °C). Soluble sugars were depleted rapidly during cool storage (especially sucrose) and were essentially exhausted after 10 weeks at 1 °C. Losses of total proteins were only 20% after 10 weeks cool storage. There is preferential catabolism of carbohydrates (sucrose, glucose, and fructose) at low temperatures, whereas, at 20 °C, protein and carbohydrate levels decline concomitantly. The patterns of sugar and protein depletion suggest that all soluble sugar is potentially accessible for metabolism, but protein catabolism is targeted to specific tissues or organs. After 5 weeks at 1 °C and placing at 20 °C, ethylene production and respiration increased to steady-state levels. Peak production of wound ethylene usually occurs 4 to 6 hours after harvest at 20 °C. After 5 or 10 weeks cool storage, this peak of production was not detected at 20 °C. After 10 weeks at 1 °C, recovery of ethylene production was delayed and the respiration rate only partially recovered to the steady level. However, chlorophyll loss is the major determinant of marketable life without cool storage, and, after 5 weeks at 1 °C, postharvest decay is the major determinant of marketable life after cool storage, particularly after 10 weeks at 1 °C.

Free access
Authors: and

Abstract

(2-Chloroethyl)phosphonic acid (ethephon) was sprayed on irrigated and non-irrigated erect (‘Cherokee’ and ‘Comanche’) blackberries (Rubus, subgenus Eubatus) before the first harvest and after the second harvest at 1000 and 1500 ppm. ‘Cherokee’ had higher and more concentrated yields and better color than ‘Comanche’. Dripirrigation increased yield and berry weight, but reduced both raw and processed fruit color. Ethephon applied before the first harvest or after the second harvest increased the amount of early fruit harvested. Ethephon reduced berry weight, percent soluble solids, titratable acidity, and increased the pH, and raw and processed product color.

Open Access
Authors: and

Abstract

The response of 4 erect blackberry cultivars to 2 levels of soil moisture and 2 hedge pruning heights was evaluated. Supplemental irrigation increased yield on all cultivars, but was most effective for the highest-yielding cultivar, ‘Cherokee,’ during the first harvest season (6.03 T/ha for irrigated plots compared to 4.22 T/ha for nonirrigated plots). Increased lateral branching and yield, with no effect on fruit quality, resulted when the new primocanes were pruned mechanically to a height of 90 cm compared to 120 cm. ‘Cherokee’ and ‘Comanche’ berries had superior color compared with that of other cultivars. Irrigation resulted in a slight reduction in percentage of soluble solids and pH.

Open Access

Abstract

Glyphosate (N-phosphonomethyl glycine) was applied to low-hanging foliage and basal shoots of ‘Concord’ grapevines (Vitis labrusca L.) at 2.2 and 4.4 kg/ha in August, September, and October 1979. All treatments were extremely injurious to grapevines. Injury was evident throughout the grapevine the following spring and during the full growing season. Growth on new shoots, visual ratings of growth reduction during the season, grape yield, and pruning weights indicate 50% or more reduction in growth as compared to the untreated check. The September treatment appeared more injurious than the August or October treatments.

Open Access

Abstract

A study was designed to examine the effects of production systems (i.e., standard bed, wide bed, and black plastic bed), a high and low plant population, and 3 harvest dates on the machine-harvested yield and quality of 2 strawberry (Fragaria × ananassa Duch.) clones. ‘Cardinal’ produced higher yields than A-5344, but had poorer quality. The wide-bed production system produced higher yields than the other production systems and had no adverse effects on quality. ‘Cardinal’ had optimum yield when produced under a low plant population, while A-5344 had optimum yield under a high plant population. Fruit quality was maintained throughout the 5- to 7-day harvest season each year.

Open Access

Abstract

Horseradish peroxidase (PO) and mushroom polyphenol oxidase (PPO) were added to strawberry purees from ‘Cardinal’ and Arkansas breeding-line 5344 to determine their influence on color during 48 hours at 30°C. Neither enzyme affected strawberry puree color or phenolic content. PO activity was reduced to near zero 24 hours after addition and PPO activity was undetectable 1 hour after addition to puree. Aeration did not affect anthocyanin and flavonoid concentrations, but increased discoloration and nonflavonoid concentration. Strawberry purees containing 50% immature plus 50% ripe fruits were poorer in color and had higher levels of flavonoids. As holding time at 30°C increased, puree color decreased.

Open Access

Abstract

A 4-year study was conducted on ‘Niagara’ grapes (Vitis labrusca L.) to examine the effects of 3 pruning severities (based on nodes retained), 3 levels of nodes/bearing unit (3, 6, and 9), 2 training systems [Geneva Double Curtain (GDC) and Bilateral Cordon (BC)], and 2 canopy management treatments (shoots positioned and shoots not positioned) on yield and fruit quality. Leaving heavy fruit loads suppressed yields in the 4th and final year of this study as a result of reduced node fruitfulness. The 3 node spurs were not as productive as the 6 and 9 node canes. GDC training produced higher yields than BC training in the 3 high yielding years of the study while maintaining vine vigor. Shoot positioning was more beneficial in increasing yields on the BC training system than on the GDC training system, because of the crowded conditions of the canes on the BC system. The effects of these variables on fruit quality were small, but the heavy fruit loads did result in fruit with a reduced percentage of soluble solids and pH, increased acidity and light color (increased CDM ‘L’ values). Shoot positioning reduced fruit pH, slightly in-creased acidity, and produced darker color (decreased CDM ‘L’ values). Under Arkansas growing conditions, if harvest is delayed beyond 14% soluble solids, it is possible that unacceptable fruit pH and acidity levels will exist.

Open Access

Abstract

Yields on ‘Concord’ grape (Vitis labrusca L.) increased as pruning severity was decreased until the 6th and last year of this study, at which time the yields tended to equalize between the 30 + 10, 50 + 10, and 70 + 10 pruning treatments. By the last year, vines pruned to the 70 + 10 level produced fruit of unacceptable quality. When the 3-node spurs were shoot-positioned, their productivity was comparable to buds on the 6- and 9-node canes, indicating the need for exposure to sunlight. The length of the bearing unit has little or no effect on fruit quality attributes. In general, shoot positioning increased yield, node productivity, the percentage of soluble solids, and lowered vine size throughout the study. Geneva Double Curtain (GDC) trained vines produced more fruit than the bilateral cordon (BC) trained vines. Fruit from GDC trained vines had a reduced percentage of soluble solids in 2 of the last 3 years, and tended to have a low pH. The most productive vines producing fruit of acceptable quality for the 6-year mean were the GDC trained, 50 + 10 pruned to 6-node bearing units, and shoot positioned.

Open Access