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Open access

D. L. Cawthon and J. R. Morris

Abstract

Retaining more fruiting nodes/vine increased yield, but reduced fruit quality in ‘Concord’ grape (Vitis labrusca L.). Geneva double curtain (GDC) training produced more fruit with better quality than a single wire cordon training system. Positioning the current season’s growth vertically toward the vineyard floor increased yields of vines pruned to short (3-node) spurs. Yield was increased by shoot positioning the season after performing the operation, however, fruit quality was improved during the season that vines were shoot positioned. Pruning vines to 6- or 9-node canes increased yield without a sacrifice of fruit quality as compared to 3-node spurs and reduced the yield increasing potential of shoot positioning. Use of longer canes, GDC training, and shoot positioning grapevines in Arkansas may allow less severe pruning than the currently recommended 30+10 pruning schedule to increase yield without a loss in fruit quality. Pruning weights were generally reduced by treatments which increased yield.

Open access

D. L. Cawthon and J. R. Morris

Abstract

Fruits were collected on weekly intervals in 1980, beginning at fruit set (ovary shatter) and continuing through harvest. Additional samples collected at harvest in 1980 and veraison in 1981 were sorted into preveraison green, postveraison green, and ripening categories. Seed number per berry was directly related to accumulation of 14C-photosynthate, fresh weight, and dry weight. Seed number had little relationship with berry content of indoleacetic acid (IAA), abscisic acid (ABA) or percentage of acidity. Percentage of soluble solids was not affected by seed number prior to veraison, but after veraison, percentage of soluble solids and intensity of juice color were inversely related to seed number. Nonripe fruit at the time of harvest had fewer seeds per berry, and fruit containing an immature seed did not accumulate ABA or enter veraison. IAA levels were similar in ripening and nonripening fruit. IAA declined to basal levels by about 55 days after peak bloom. ABA began to increase after 65 days from peak bloom and berry changes associated with veraison occurred after 72 days.

Open access

J. R. Morris and D. L. Cawthon

Abstract

Single and split applications of (2-chloroethyl)phosphonic acid (ethephon) at different concentrations to ‘Concord’ grapes(Vitis labrusca L.)did not influence maturation. When ethephon was applied 8 days prior to harvest, abscission was enhanced and postharvest alcohol accumulation was reduced when fruit was shaken from the vine and held at 30°C for up to 24 hours.

Open access

J. R. Morris and D. L. Cawthon

Abstract

A site was prepared with 2 distinctly different soil depths and a vineyard of ‘Concord’ grapes (Vitis labrusca L.) was established with in-row spacings of 1.52, 1.83, 2.13, 2.44, and 3.05 m. Wider in-row vine spacings resulted in increased vine yields on deeper soils to the point that yields per meter of cordon and per hectare were not reduced; but yield per meter of cordon and per hectare was reduced on the shallow soil when in row vine spacings exceeded 2.44 m. There were few effects on juice quality from either soil depths or in-row vine spacings.

Open access

J. R. Morris and D. L. Cawthon

Abstract

Firm-fruited strawberries (Fragaria × ananassa Duch.) for processing can be mechanically harvested, properly handled and then held for up to 48 hours at 24°C for 7 days at 1.7° without excessive quality loss. High mold count and a reduction in other quality attributes occur after 96 hours at 24°. Ripe fruit held for 48 hours at 24° and then processed was acceptable to a sensory panel. The effects of overwrapping appeared to be limited to quality changes associated with dessication. Benomyl treatment had a suppressing effect on mold count and reduced loss of soluble solids.

Open access

J. R. Morris, L. D. Ray, and D. L. Cawthon

Abstract

Succinic acid-2,2-dimethylhydrazide (daminozide) applied at 1800 ppm to 10-year-old ‘Babygold-5’ and ‘Babygold-8’ peach trees (Prunus persica (L.) Batsch) at pit hardening advanced fruit maturity and increased tolerance of low soluble solids fruit by improving flesh color. Fruit softening, the disappearance of flesh chlorophyll, and reductions in puree viscosity were the primary benefits obtained from the application of daminozide. Daminozide advanced maturation generally, rather than concentrating the fruit into a more uniform maturity class. Flesh color and acidity were highly correlated with loss of fruit firmness of both control and daminozide-treated fruit, but daminozide treated fruit improved in flesh color more rapidly than control fruit as firmness decreased. Acidity remained consistently higher for treated fruit at all firmness levels. The mechanism by which daminozide advanced maturity did not appear to be active during postharvest holding of these clingstone cultivars. Further ripening as a result of postharvest storage of both treated and control fruit occurred at about the same rate during a 2, 4 or 6 day period at 18°C.

Open access

J. R. Morris, D. L. Cawthon, and J. W. Fleming

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

J. R. Morris and D. L. Cawthon

Abstract

Naphthaleneacetic acid (NAA) was applied to 10-year-old ‘Concord’ grapevine trunks at 0, 2, 4, and 8% concentrations. Best control of shoots on trunks was obtained with the 4 and 8% concentrations with no visual foliar injury or detrimental effects on yield, vine size, or fruit quality. One application of NAA at 8% reduced the number of trunk shoots for 3 years, but 100% control was obtained only in the year of application.