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Significant differences in fruit color were created with fruit cluster thinning (20, 40, and 60 clusters/vine), cluster shading (full sun as control, 55% shading, and 95% shading using shading cage constructed of shade cloth), and defoliation (3, 6, 9, 12, and 15 leaves/cluster). Fruit cluster shading and defoliation treatments decreased red fruit color (characterized by Hunte Color a). Fruit cluster thinning increased red fruit color. Anthocyanin profile of Reliance grape was characterized as cyaninidin-3-glucoside and delphinidin-3-glucoside using Paper Chromatography and Thin Layer Chromatography. Analyses of total anthocyanin content (pH shift method), individual anthocyanin and soluble carbohydrates content (High Performance Liquid Chromatography), are being conducted to determine effects of carbohydrate allocation to fruit and sun light on fruit color of Reliance grapes.
Factorial treatments of vine spacing, shoot density and foliar applications of KNO3 were imposed on 9-year-old Seyval grapevines during 1989. Rows were spaced 3.05 m apart; vines within the row were spaced 1.2, 1.8 or 2.4 m apart and trained to a bilateral cordon. Shoots were thinned to 10, 20 or 30/m of canopy. A solution containing 6 kg of KNO3/379 liters of water was applied as a foliar spray at 2-week intervals between June 1 and August 1, 1989 (5 applications). Each shoot was thinned to one cluster prior to full bloom. Vines spaced at 1.2, 1.8 and 2.4 m produced an average of 4.2, 5.9 and 7.3 kg/vine, respectively (11.3, 10.6 and 9.8 MT/ha). Cluster weight averaged .22 kg; fruit maturity averaged 19.7°Brix for all treatments. Applications of KNO3 increased foliar N, K, Fe, B, Cu and Na, but decreased P, Ca, Mg, Mn, and Zn. As vine spacing increased the concentration of foliar N, P, K decreased. As shoot density increased N, P, K, B, and Cu decreased, while Ca, Mg, Mn and Na increased. The experiment will be repeated in 1990.
Factorial treatments of vine spacing, shoot density and foliar applications of KNO3 were imposed on 9-year-old Seyval grapevines during 1989. Rows were spaced 3.05 m apart; vines within the row were spaced 1.2, 1.8 or 2.4 m apart and trained to a bilateral cordon. Shoots were thinned to 10, 20 or 30/m of canopy. A solution containing 6 kg of KNO3/379 liters of water was applied as a foliar spray at 2-week intervals between June 1 and August 1, 1989 (5 applications). Each shoot was thinned to one cluster prior to full bloom. Vines spaced at 1.2, 1.8 and 2.4 m produced an average of 4.2, 5.9 and 7.3 kg/vine, respectively (11.3, 10.6 and 9.8 MT/ha). Cluster weight averaged .22 kg; fruit maturity averaged 19.7°Brix for all treatments. Applications of KNO3 increased foliar N, K, Fe, B, Cu and Na, but decreased P, Ca, Mg, Mn, and Zn. As vine spacing increased the concentration of foliar N, P, K decreased. As shoot density increased N, P, K, B, and Cu decreased, while Ca, Mg, Mn and Na increased. The experiment will be repeated in 1990.
Abstract
Succinic acid-2,2-dimethylhydrazide (daminozide, SADH) applied to mature ‘Concord’ grape vines (Vitis labrusca L.) at 500 and 1000 ppm at first and at 50% bloom, was observed to increase fruitfulness and yield by increasing cluster weight. During 7 years cluster weight increases were associated with 2 to 6% decreases in berry size and 14 to 22% increases in berry number. Daminozide did not affect the number of seeds per berry, but did reduce weight per berry. Thus, increases in crop yield of up to 20 to 25% were obtained by increasing cluster weight and not by increasing cluster number. Daminozide increased total acid concentration slightly but had no effect on pH. Soluble solids were reduced by daminozide when yield increases, due to daminozide, were above 2 kg/vine. The effect on soluble solids appeared to result from increased productivity rather than from direct effect of the chemical. Daminozide reduced vine size more at the 1000-ppm than the 500-ppm rate.
Abstract
Comparisons were made of the composition of ‘Valencia’ oranges, Citrus sinensis Osbeck, from orchards in 6 major climatic zones used for citrus culture in the U. S. Six orchards, selected in a compact area in each location, were measured and sampled at intervals during 2 crop seasons. The locations were: Orlando, Fla.; Weslaco, Tex.; Tempe, Ariz.; Indio, Calif.; Riverside, Calif.; Santa Paula, Calif. Statistical evaluations showed that the seasonal trends for most measurements differed significantly among locations.
Observations on flowering showed that full-bloom occurred from 1 to 2 months later in the Far-Western locations than in Texas and Florida. The extremes of the interval between an thesis and the beginning of ripening (a 9 to 1 ratio of total soluble solids to acid in juice) varied from 71/2 to 81/2 months in Weslaco, to 14 to 15 months in Santa Paula, but earliness or lateness of maturity could not be relatd in any simple, obvious manner to the characteristic of the seasonal temperature regimes in the 6 locations. In general, rinds were thinner, smoother and slower to color, and fruits larger, and juicier in Orlando and Weslaco than in the Far-Western locations. Total soluble solids and ascorbic acid in juice at comparable stages of maturity were not influenced in a predictable manner by location, although significant differences occurred in a given season. Of the juice constituents, the acids appear to be the most consistently influenced by climatic conditions during the rapid growth and maturation periods of fruit development. The warmer the climate, the more rapid was the rate of decrease of total acid concentration. Seediness of fruit was influenced by both location and season. Measurements of comparable samples of fruit obtained from widely divergent climatic parameters suggest that the numerous growth and metabolic processes involved in ripening of citrus fruits have independent internal controlling mechanisms. Apparently these processes interact in different ways with external environmental factors, and are not dominated by a pervasive, common internal maturity factor.