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

The effect of imbibition and drying rates on colyledon cracking in snap beans, Phaseolus vulgaris L., was studied. Six snap bean cultivars, representing various degrees of susceptibility to cotyledon cracking, were compared. Data indicated that differences in the rate of imbibition and drying were not responsible for differences in susceptibility to cotyledon cracking. The crack-resistant ‘Improved Higrade’ and moderately-resistant ‘Earliwax’ imbibed water faster than the crack-susceptible cultivars. Anatomical studies indicated that cracking was more frequent across the cell walls of the cotyledon cells than along the middle lamellae in all cultivars.

Open Access

Abstract

Temperature of fruit of Vitis labrusca L. cv. Concord at harvest was the primary factor governing the rate of postharvest quality changes. Fruit harvested at mid-day at 32°C remained at that temperature inside a bulk pallet box for 72 hours, regardless of diurnal temperature fluctuations. Without addition of SO2, alcohol concentration steadily increased after 12 hours holding the mechanically-harvested grapes in a bulk pallet box and reached 3% after 72 hours. Loss of soluble solids began immediately after harvest and after 72 hours, 44% of the soluble solids present at the time of harvest had been lost. Addition of S02 at harvest or no later than 6 hours after harvest aided in slowing postharvest deterioration. The addition of 80 or 160 ppm SO2 to a bulk pallet box of grapes mechanically harvested at a temperature of 35° was as effective in retarding postharvest deterioration of the quality attributes determined in this study as was harvesting at 24°. Harvesting at a cool temperature (24°) and SO2 addition will allow for extended holding of the raw product with minimal alcohol production and raw product quality loss.

Open Access

Abstract

Succinic acid-2, 2-dimethylhydrazide (daminozide), at rates of 0, 1000, and 2000 ppm, was applied between first and peak bloom to 2 adjacent ‘Concord’ (Vitus labrusca L.) vineyards: a 9-year-old vineyard with a histoty of good fruit set and a 19-year-old vineyard with a history of poor fruit set. No significant yield increase was obtained in the young vineyard, but there was a tendency for lower soluble solids and poorer juice color due to daminozide. Yields were increased by 2.4 and 3.3 MT/ha by 1000 and 2000 ppm daminozide, respectively, in the older vineyard with no significant effect on juice quality. The one-year increase in yield of grapes in the older vineyard was accompanied by a reduction in vine size.

Open Access

Abstract

Numerical rating scales and their descriptive equivalents for firmness, visual quality, decay, butt discoloration, wilting, and other defects of lettuce (Lactuca sativa L.) are described. Also presented are scoring systems for brown stain, russet spotting, and rusty-brown discoloration of crisphead lettuce that consider severity of lesions, proportion of leaf affected and number of leaves affected in a head.

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

Mechanically harvested fruits of A-5344 and ‘Earlibelle’ strawberry (Fragaria × ananassa Duch.) were stored at 24°C for 72 and 120 hours in atmospheres containing acetaldehyde (Aa) with and without prior dipping in 0 to 1.5% acetaldehyde solutions. Aa atmospheres and a combination of atmospheres and dips were most effective in maintaining visual color, freedom from browning, and product acceptability of machine harvested strawberries for processing. Fruit stored in atmospheres containing Aa vapor increased in acidity by 72 hours.

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

Abstract

CO (5 and 10%) + 4% O2 atmospheres retarded growth of Botrytis cinerea Pers. ex Fr. (in vitro) and reduced decay incidence and severity on inoculated tomatoes (Lycopersicon escuientum Mill.) harvested at the mature-green (MG) or pink (P) stage and held at 12.5°C for up to 14 days (MG) or 10 days (P). This reduction was still evident after holding for an additional 2 to 3 days (P) or 7 days (MG) at 20° in air. CO + 4% O2 atmosphere was more effective than CO + air atmosphere in all experiments. CO + air treatments increased CO2 and C2H4 production rates and hastened ripening of MG fruits, while CO + 4% O2 atmosphere had no or very small effect on these physiological responses relative to 4% O2 atmosphere at 12.5°. After transfer to air at 20°, fruits previously exposed to CO exhibited slightly higher CO2 and C2H2 production and faster ripening than control fruits. CO added to air or 4% O2 did not affect ripening rate of fruits picked at the breaker, turning, or pink stages. CO + air or 4% O2 atmosphere slowed down softening of pink fruits during a 7- or 14-day storage period at 12.5°. Fruits subjected to CO + 4% O2 for 7 days maintained their sugar and acid content better than control fruits.

Open Access