scholarly journals Influence of Irradiance and Period of Exposure on Fruit Set of French-American Hybrid Grapes

2001 ◽  
Vol 126 (3) ◽  
pp. 283-290 ◽  
Author(s):  
D.C. Ferree ◽  
S.J. McArtney ◽  
D.M. Scurlock

Vines of container grown `DeChaunac', `Vidal blanc', `Seyval blanc' and `Chambourcin' grapes were subjected to 5 days of 80% shade at prebloom, bloom or 2 and 4 weeks after bloom. Fruit set, cluster weight, berries per cluster and juice components [soluble solids concentration (SSC), pH and titratable acidity] of `DeChaunac' and `Vidal blanc' were not affected by a short period of intensive shade. `Chambourcin' was sensitive to a shade period near the time of bloom for most of the aforementioned factors, while `Seyval blanc' was intermediate in sensitivity. Shot (green, hard, and undersized) berries of `Chambourcin' and `Seyval blanc' were increased by a 5-day period of shade 2 or 4 weeks after bloom. In a second study, container-grown `Chambourcin' on 3309C (V. riparia × V. rupestris) with one or two clusters and `Vidal blanc' with one cluster were subjected to the following light regimes beginning at bloom for 5 weeks: supplemental light, ambient greenhouse light and 30%, 50% or 80% shade. Yield, fruit set, specific leaf weight (leaf dry weight/leaf area), saturation index, and total leaf chlorophyll increased linearly with increasing irradiance. `Chambourcin' juice pH, SSC, leaf chlorophyll a/b ratio, cluster color development and hue angle decreased as irradiance increased, likely related to crop reduction. Responses in `Vidal blanc' followed similar trends, but differences were not as great. Results demonstrate that light is an important determining factor in fruit set of French-American hybrid grapes and fruit set of some cultivars are sensitive to short periods of intense shade.

2004 ◽  
Vol 14 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Frederick S. Davies ◽  
Glenn R. Zalman ◽  
Ed Stover ◽  
Scott Ciliento

EcoLyst, a formulation of N-N-diethyl-2-(4-methylbenzyloxy) ethylamine hydrochloride containing 1 g/floz [4.5 oz/gal (33.8 g·L-1)] a.i., is a plant growth regulator that has been reported to increase soluble solids concentration (SSC) in juice oranges by 0.6% to 1.2%. Our objectives were to determine the effectiveness of EcoLyst application for increasing SSC in Florida oranges (Citrus sinensis) and grapefruit (C. paradisi), and to identify the optimum rate and time of application. Experiments were conducted for three seasons using `Hamlin,' `Pineapple,' and `Valencia' sweet oranges; and for two seasons using `Flame,' `Marsh,' and `Ray Ruby' grapefruit, all in commercial groves. EcoLyst was applied at 6 and 12 floz/acre (0.44 and 0.88 L·ha-1) for oranges and 16 and 32 ppm (mg·L-1) [effectively 9 and 18 floz/acre (0.66 and 1.32 L·ha-1) in most sprays] for grapefruit, and included Silwet L-77 adjuvant at 0.05%. Applications were made at several stages of development from prebloom to initial fruit set. In all cases, SSC was determined as juice corrected SSC, by adjusting refractometer readings based on titratable acidity. In 13 trials with sweet orange only five displayed significant increases in SSC (P ≤ 0.05) resulting from EcoLyst application. Two additional trials produced SSC increases significant at P < 0.10. Even where significant increases in SSC occurred they were typically observed in only one harvest and at one time of application and were always relatively low in magnitude (highest increase over controls was 0.38%). No rate or timing of EcoLyst application was consistently associated with best response, although eight of nine SSC increases observed in orange occurred with applications ranging from prebloom to 25% open flowers. Only one significant increase in SSC was observed in five trials with grapefruit. In these studies, increases in SSC resulting from EcoLyst application were neither sufficiently consistent nor large enough to justify a recommendation for commercial use in Florida citrus.


HortScience ◽  
2008 ◽  
Vol 43 (3) ◽  
pp. 885-890 ◽  
Author(s):  
Gerry H. Neilsen ◽  
Denise Neilsen ◽  
Peter Toivonen ◽  
Linda Herbert

A randomized, complete block, split-plot experimental design with six replicates was established and maintained annually for the first five fruiting seasons (1999 to 2003) in a high-density apple [Malus sylvestris (L) Mill var. domestica (Borkh.) Mansf] orchard on M.9 rootstock planted in Apr. 1998. Main plot treatments involved eight different nutrient regimes, each containing three tree subplots of each of five different cultivars (Ambrosia, Cameo, Fuji, Gala, and Silken). This report compares a +phosphorus (P) treatment, involving annual fertigation at bloom time of 20 g P/tree as ammonium polyphosphate (10N–15P–0K), to a −P treatment. Both treatments also received nitrogen, potassium, and boron nutrients through fertigation. Drip fertigation of P increased 2 M KCl-extractable P to 0.4-m depth within 0.5-m distance of the drippers. Leaf and fruit P concentrations were consistently increased by the +P treatment with few differences among cultivars. P-fertigated trees also had a 20% increase in cumulative yield overall cultivars during the first five fruiting seasons. Standard fruit quality measurements, including fruit size, soluble solids concentration, titratable acidity, and red coloration were unaffected by P application. However, reductions in incidence of water core at harvest, increased resistance to browning, and elevated antioxidant content of harvested fruit measured in some years imply a role for P in apple membrane stability. The cumulative results indicate that applications of 20 g P as ammonium polyphosphate annually at bloom would be advantageous for apples receiving adequate fertigated applications of nitrogen, potassium, and boron. Best apple performance was associated with leaf P concentrations above 2.2 mg·g−1 dry weight and fruit P concentrations between 100 and 120 mg·kg−1 dry weight.


HortScience ◽  
1997 ◽  
Vol 32 (2) ◽  
pp. 284-287 ◽  
Author(s):  
P. Olienyk ◽  
A.R. Gonzalez ◽  
A. Mauromoustakos ◽  
W.K. Patterson ◽  
C.R. Rom ◽  
...  

Clingstone peach [Prunus persica (L.) Batsch cv. Allgold] trees were fertilized once with 45 or 90 kg N/ha at budbreak or twice with 22.5 or 45 kg N/ha at budbreak and after harvest. A nonfertilized control was included. Fruits from all treatments were made into puree, and objective and subjective qualities were evaluated. Puree from the N treatments and the control did not show significant differences in Color Difference Meter (CDM) `L' and hue angle, pH, titratable acidity (TA), soluble solids concentration (SSC), SSC: TA ratio, viscosity, ascorbic acid, Ca, K, phenolic and nitrates concentration. Puree from the control and 22.5 kg N/ha applied twice had significantly lower CDM `a', `b', and chroma values than from the other treatments. The split applications of N significantly reduced levels of Ca and ascorbic acid. N rate and number of applications interacted for `a' and K. When N was applied twice at 22.5 kg·ha-1, `a' and K decreased, but this response was absent when N was applied twice at 45 kg·ha-1. Puree from the nonfertilized control was rated lower by panelists for sensory quality than that from the fertilized trees. Peach puree from trees fertilized once with 45 kg N/ha at budbreak had the best overall sensory quality.


1998 ◽  
Vol 123 (5) ◽  
pp. 755-761 ◽  
Author(s):  
Ann K. Hummell ◽  
David C. Ferree

`Seyval blanc' grapevines (Vitis spp.) were cluster thinned 7 days after full bloom to 20, 40, and 80 clusters per vine to create light, moderate, and heavy crop levels. Vines were also shoot positioned at veraison to create exposed, partially shaded, and densely shaded cluster microclimates to examine the interactions between crop level and light exposure on fruit composition during stage III of berry development. Clusters were harvested using one of two criteria: on the same date or at similar soluble solids concentrations. Cluster mass and berries per cluster decreased with increasing crop level regardless of harvesting criterion. When harvested on the same date, soluble solids concentration, pH and malic acid concentration of juice decreased with increasing crop level. When harvested at similar soluble solids concentrations, increasing crop level delayed harvest and reduced titratable acidity (TA), tartaric acid, and malic acid. As cluster light exposure increased, soluble solids and pH increased and TA and malic acid decreased when clusters were harvested on the same date. When harvested at similar soluble solids concentration, increasing light exposure advanced harvest date and pH, TA, tartaric acid, and malic acid decreased. If clusters were harvested on the same date, significant interactions were found between crop level and light exposure for soluble solids concentration and the hue angle of berries. Significant interactions were found for berry mass, pH, TA, and tartaric acid when clusters were harvested at similar soluble solids. When harvested on the same date in 1995, soluble solids concentration of densely shaded clusters declined as crop level increased, whereas the soluble solids of exposed and partially shaded clusters declined as cluster number increased from 20 to 40 clusters per vine but remained constant from 40 to 80 clusters. In 1995, the hue angles of exposed clusters decreased with increasing crop level, while those of partially shaded and densely shaded clusters increased. When harvested at similar soluble solids concentration, berry mass of exposed and partially shaded clusters was similar across crop levels, whereas berry mass of densely shaded clusters declined as crop levels increased. Based on contribution to treatment error, crop level influenced pH more, and TA less, than did light exposure if harvested at the same date. Conversely, crop level influenced TA more, and pH less, than did light exposure if harvest was done at similar soluble solids concentrations. Regardless of harvest criterion, crop level influenced yield components, and soluble solids concentration to a greater extent and hue angle to a lesser extent than did light exposure.


HortScience ◽  
1998 ◽  
Vol 33 (4) ◽  
pp. 594e-594
Author(s):  
Charles J. Graham

Research is needed to better understand the influence of cell volume and fertility on watermelon transplant size and field performance in order to determine the most economic production practices. `Jubilee' watermelon transplants were grown using a 4 x 4 factorial experimental design consisting of 4 cell volumes (30.7, 65.5, 147.5, and 349.6 cm3) and 4 fertility rates (0, 1/4, 1/2, and full-strength Hoagland's solution). Transplant shoot dry weight significantly increased as cell volume and fertility increased. Increasing cell volume linearly increased watermelon number/ha and tons/ha for early and total harvest in 1995. The average weight per watermelon significantly increased for early-harvested fruit but not for total harvest as cell volume increased in 1995. Soluble solids concentration linearly increased with increasing cell volume for early and total harvests in 1995. Cell volume had no significant influence on the harvest parameters measured in 1997. In 1995, increasing fertility linearly increased watermelon number/ha and tons/ha for early harvests. Increasing fertility increased the soluble solids concentration linearly for early-harvested watermelons in 1997 but not in 1995. Fertility rate had no significant influence on any of the other harvest parameters measured in 1995 and 1997. The growing conditions and disease pressure in 1997 reduced melons/ha, yield, and soluble solids content when compared to 1995 values. The half-strength Hoagland's solution produced the greatest number of watermelons/ha, tons/ha, and the highest soluble solids concentration in 1995 and 1997. Pretransplant nutritional conditioning had no significant effect on total `Jubilee' watermelon production in Louisiana for 1995 and 1997.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 510f-511 ◽  
Author(s):  
D.C. Ferree ◽  
S.J. McArtney ◽  
D.M. Scurlock

Four French–American hybrid grape cultivars grown in a greenhouse were subjected to 5 days of 80% shade at four different times around bloom. Fruit set of `Seyval' was reduced by shade imposed before, during, or immediately after bloom. `Vidal' and `Chambourcin' were less sensitive, with fruit set reduced only by shade at bloom. Shade had little effect on fruit set of `DeChaunac'. In a second study, `Chambourcin' vines were exposed to ambient, ambient plus supplemental lights, and 30%, 50%, or 80% shade for 5 weeks beginning just prior to bloom. Fruit set was positively related to light intensity. At harvest, soluble solids, pH, and hue angle had a negative linear relationship to light level. Fruit color developed earliest and most rapidly with the reduced light treatments applied at bloom. Cluster weight was positively related to light intensity.


2018 ◽  
Vol 40 (3) ◽  
Author(s):  
José Gilberto Sousa Medeiros ◽  
Luiz Antonio Biasi ◽  
Claudine Maria de Bona ◽  
Francine Lorena Cuquel

Abstract Studies on adaptation to the cultivation site are necessary for the recommendation of new cultivars. The aim of this study was to evaluate the phenological development, productivity and fruit quality of eight blueberry cultivars from the rabbiteye group (Aliceblue, Bluebelle, Bluegem, Briteblue, Climax, Delite, Powderblue and Woodard) and two from the highbush group (Georgiagem and O’Neal) under humid subtropical conditions in the 2012/2013, 2013/2014 and 2014/2015 cycles. Beginning and end of flowering, beginning and end of harvesting, fruit set, production, mass, diameter, pH, content of soluble solids, titratable acidity, ratio and coloring were evaluated. The evaluated cultivars presented flowering in the period from July to September, concentrating harvest in the months of November and December. The highest fruit set was observed in Delite, Climax, Briteblue and Powderblue cultivars. There were differences among cultivars regarding fruit mass, size, pH, content of soluble solids and acidity. The results showed that the cultivars exhibited blue color with few variations over the evaluation years. Cultivars with the best productive performance under humid subtropical climate conditions are Bluegem, Delite, Climax and Powderblue.


1990 ◽  
Vol 115 (2) ◽  
pp. 265-269 ◽  
Author(s):  
Joshua D. Klein ◽  
Susan Lurie

The benefits conferred by a prestorage heat treatment on poststorage quality of apples (Malus domestics Borkh.) were measured on `Anna', a non-storing early cultivar, and `Granny Smith', a long-storing late cultivar. The major benefit was a decrease in rate of apple softening, both during OC storage and during simulated shelf life at 20C. Soluble solids concentration was not affected by heat treatment, but titratable acidity was reduced. Ethylene production after heat treatment and storage was similar to or higher than that of control apples, but respiration was lower. The optimum temperature and time combination for prestorage treatment of both cultivars was 4 days at 38C.


Plants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 206 ◽  
Author(s):  
Madeleine Peavey ◽  
Ian Goodwin ◽  
Lexie McClymont ◽  
Subhash Chandra

Some cultivars of Pyrus communis develop mature fruit with a distinctive red blush. Investigating the patterns of pear colour development in response to sunlight has implications for orchard management of these pears. The objectives of these experiments are to study the seasonal patterns of colour development and investigate the influence of shade and sunlight exposure on the red colour and harvest quality of blush pears “ANP-0118” and “ANP-0131”. Several long, medium and short shading treatments were applied at different stages of fruit development from 28 (“ANP-0131”) and 29 (“ANP-0118”) days after full bloom (DAFB) until harvests at 119 DAFB (“ANP-0118”) and 175 DAFB (“ANP-0131”). Fruits were measured every three weeks for colour parameters (a*, hue angle, chroma) and at harvest for quality parameters (fresh weight, visual assessments of percentage blush coverage and blush intensity, flesh firmness and soluble solids concentration). In the unshaded control, red colour increased during the growing season (increase in a* value and decrease in hue angle), as well as increasing in chroma value. Periods of shading during the season negatively affected red colour in both cultivars, as evidenced by significant decreases in a* value and increases in hue angle. Shaded fruits that were subsequently re-exposed to sunlight reacted with a dynamic increase in a* value and decrease in hue angle. Fruit shaded for the length of the experiment or prior to harvest had significantly lower a* values than the control at harvest. Visual assessment at harvest of percentage blush coverage and blush intensity were significantly affected by shading in both cultivars. Shading treatments applied early in the experiment had a negative effect on the fresh fruit weight of “ANP-0118”.


2019 ◽  
Vol 33 (2) ◽  
pp. 380-385
Author(s):  
Nicholas T. Basinger ◽  
Katherine M. Jennings ◽  
David W. Monks ◽  
Wayne E. Mitchem

AbstractStudies were conducted at six locations across North Carolina to determine tolerance of ‘Sunbelt’ grape (bunch grape) and muscadine grape (‘Carlos’, ‘Triumph’, ‘Summit’) to indaziflam herbicide. Treatments included indaziflam (0, 50, 73 g ai ha–1) or flumioxazin (213 g ai ha–1) applied alone in April, and sequential applications of indaziflam (36, 50, 73 g ai ha–1) or flumioxazin (213 g ai ha–1) applied in April followed by the same rate applied in June. No crop injury was observed across locations. Muscadine yield was not affected by herbicide treatments. Yield of ‘Sunbelt’ grape increased with sequential applications of indaziflam at 73 g ha–1 when compared to a single application of indaziflam at 50 g ha–1 or flumioxazin at 213 g ha–1 in 2015. Sequential applications of flumioxazin at 213 g ha–1 reduced ‘Sunbelt’ yield compared to a single application of indaziflam at 73 g ha–1 in 2016. Trunk cross-sectional area was unaffected by herbicide treatments. Fruit quality (soluble solids concentration, titratable acidity, and pH) for muscadine and bunch grape was not affected by herbicide treatments. Indaziflam was safe to use at registered rates and could be integrated into weed management programs for southern US vineyards.


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