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The influence of bilateral cordon (BC) and cane training systems and level of pruning severity on vegetative and reproductive characteristics of Vitis hybrid `Suwannee' were determined from 1987 to 1989. In 1987, yield and quality were similar on BC- and cane-trained vines. In 1988, shoot count, yield, and quality were similar regardless of training system and pruning severity (50, 70, or 90 nodes per vine). When data from both training systems were combined, yield was related to the number of shoots. Vines pruned more severely compensated by producing more shoots from non-count (non-node) positions on the canes, cordon, or spurs. Similarly, in 1989 yield and berry quality were not affected by training system or levels of pruning severity (50, 70, 90, or 110 nodes), although berry weight was affected by training system, and shoot count and shoot length were affected by level of pruning severity. Interactive effects of training system and pruning level were not significant in either year. An analysis of combined data for 1989 indicated that yield was affected by the number of nodes and shoots. Thus, `Suwannee' may be trained to the BC system, which is more readily adapted to mechanization. Pruning to a specific number of nodes per vine was not critical.
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.
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.
Abstract
A factorial study was designed to examine the effects of fruit maturities, juice extraction temperatures, storage time, and storage temperature on the quality of ‘Concord’ grape (Vitis labrusca L.) juice. Mature grapes produced juice with superior sensory quality and better objective color initially than less-mature grapes, but juice from grapes at both maturities had similar sensory quality after 18 months. The high extraction temperature (99°C) resulted in juice with better color initially than extraction at 60°, but juice extracted at 85° or 99° resulted in greater browning and loss of total anthocyanins during storage than extraction at 60°. High storage temperature (35°) greatly accelerated quality loss. Sensory color ratings correlated better with a ratio of absorbances at 520/430 nm (r = 0.95) and a/b (r = 0.92) than other objective color measurements.
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.
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.
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.
Cantaloupes (Cucumis melo) in three separate trials were cut into 1-inch cubes and irradiated at 0, 0.25, 0.5, 0.75, 1.0, 1.25, or 1.5 kGy; 0, 0.1, 0.2, 0.3, 0.4, 0.5, or 0.7 kGy; and 0, 0.3, 0.6, or 0.9 kGy, respectively. They were then stored in air at 3 °C for up to 20 days, and respiration rate, measured as carbon dioxide (CO2) production, microbiological counts [total plate count (TPC) and yeast and molds], texture, and color were measured during storage. Respiration rates were initially higher in irradiated cantaloupe. After 8 days, respiration was similar between irradiated and control fruit. Irradiation moderated increases in respiration in a dose-dependent manner. Highest irradiation doses resulted in initial TPC reductions of 1.5 log compared to the non-irradiated controls, and also prevented the 2.5 to 3 log TPC increases seen in controls after 10 to 11 days of storage. Texture differed on day 1, when controls were most firm, but irradiation maintained greater firmness than controls after day 7. Irradiation of fresh-cut cantaloupe has potential for shelf life extension and for integration with modified atmosphere packaging systems.