Effect of GA3 and Pollination on Fruit Set and Development in Rabbiteye Blueberry

To determine if multiple applications of GA3 would increase size of parthenocarpic fruit, and to assess the interaction between GA3 applications and pollination, `Beckyblue' rabbiteye blueberry (Vaccinium ashei Reade) flowers were treated with single or multiple applications of GA3 alone or in combination with full or partial pollination. Single or multiple applications of GA3 resulted in similar or increased fruit set compared with pollination, and increased fruit set compared with no pollination. GA3 applications decreased fruit mass and increased the fruit development period in comparison with pollination alone. Multiple, late applications of GA3 were ineffective in overcoming these effects. Partial (nonsaturating) pollination resulted in an average fruit set of 60%, while set following GA3 treatment in combination with full or partial pollination averaged 85%. Fruit mass was greater in the full pollination ±GA3 treatments than in all other treatments. The number of large seeds and seed mass per fruit were greatest in the full pollination treatment, and were significantly decreased by all treatments in which GA3 and/or partial pollination were used; however, there were no concomitant effects of GA3 in delaying the fruit development period. Our results indicate that under optimal pollination conditions, no detrimental effects of GA3 applications on fruit set, fruit size, or fruit development period in blueberry are to be expected, even though GA3 reduces seed number and seed mass. Furthermore, GA3 applications appear to be beneficial in increasing fruit set under suboptimal pollination conditions, although smaller fruit are to be expected under such conditions. Chemical name used: gibberellic acid (GA3).

Download Full-text

Effect of Bee Pollination and GA3 on Fruit Size and Maturity of Three Rabbiteye Blueberry Cultivars with Similar Fruit Densities

HortScience ◽

10.21273/hortsci.34.6.1106 ◽

1999 ◽

Vol 34 (6) ◽

pp. 1106-1107 ◽

Cited By ~ 8

Author(s):

D. Scott NeSmith ◽

Gerard Krewer

Keyword(s):

Gibberellic Acid ◽

Fruit Development ◽

Fruit Size ◽

Primary Factor ◽

Fruit Maturation ◽

Bee Pollination ◽

Maturation Period ◽

Vaccinium Ashei ◽

Development Period ◽

Fruit Load

Plants of the rabbiteye blueberry (Vaccinium ashei Reade) cultivars Brightwell, Climax, and Tifblue were subjected to pollination with bees or to applications of 250 mg·L-1 of gibberellic acid (GA3) to examine the influence on fruit size and maturation period. Plants were thinned to a similar fruit density (FD) 4 weeks after anthesis. `Tifblue' and `Climax' fruit were smaller on GA3-treated than on bee-pollinated plants, but no difference was observed for `Brightwell'. The fruit maturation period for `Climax' was not affected by treatments, but `Brightwell' and `Tifblue' fruit on pollinated plants ripened 2 weeks earlier than fruit on GA3-treated plants. These data suggest that excess fruit load is not the primary factor responsible for the smaller fruit size and lengthened fruit development period resulting from GA3 applications to rabbiteye blueberries.

Download Full-text

Fruit Set, Retention, and Developmental Rates Vary in Massachusetts Cranberry Cultivars

HortScience ◽

10.21273/hortsci.39.4.849e ◽

2004 ◽

Vol 39 (4) ◽

pp. 849E-849

Author(s):

Carolyn J. De Moranville*

Keyword(s):

Fruit Development ◽

Fruit Set ◽

Fruit Size ◽

Growth Curves ◽

Lag Phase ◽

Variable Yield ◽

Small Fruit ◽

Developmental Rates ◽

Hybrid Cultivar ◽

Fruit Mass

Cranberry fruit development was studied in 3 years at the Univ. of Massachusetts Cranberry Station farm. Beginning at 4 weeks from 50% out of bloom and continuing until late Sept, 5 replicate samples of 25 fruiting uprights were collected biweekly from each of 7 cultivar beds. Fruit were removed from uprights and sorted into size classes using stacked soil sieves (16-, 12.5-, 9.5-, and 5.6-mm grids). Fruit from each class was counted and weighed. `Ben Lear', a native Wisconsin selection and the fourth most planted cultivar in Massachusetts, consistently produced the greatest yield (mass) of fruit. This was attributed to consistent fruit retention and large fruit size (majority of fruit at harvest were >12.5 mm in dia). In comparison, `Pilgrim', a large-fruited hybrid cultivar, was near the median for fruit yield due to poor fruit set (≈1.2 berries per upright compared to ≈1.6 for `Ben Lear'). `Stevens', the hybrid cultivar of choice in the MA cranberry industry, had yield similar to `Ben Lear' in only 2 of 3 years. Fruit set and retention in `Stevens' was less than that in `Ben Lear', but larger mass of individual fruit in `Stevens' generally made up for fewer fruit produced. Native cultivars `Early Black' and `Howes', which account for >50% of the MA cranberry acreage, had variable yield attributable to variable fruit set and retention by year. These cultivars bear small fruit (≈1 gm/berry; only half of berries >12.5 mm in diameter). Growth curves showed evidence of a `lag phase' in cranberry fruit mass accumulation occurring approximately at the mid-point of fruit development. Although much of the final fruit mass had accumulated by Sept, additional mass did accumulate up to the harvest of the beds (≈1Oct.). This has implications for growers who harvest fruit in early Sept for `white' cranberry juice.

Download Full-text

GIBBERELLIC ACID ENHANCES FRUIT SET OF PHYSICALLY DAMAGED BLUEBERRY FLOWERS

HortScience ◽

10.21273/hortsci.30.3.430c ◽

1995 ◽

Vol 30 (3) ◽

pp. 430c-430

Author(s):

Gerard Krewer ◽

Scott NeSmith ◽

Mark Rieger ◽

Ben Mullinix

Keyword(s):

Gibberellic Acid ◽

Fruit Development ◽

Fruit Set ◽

The Other ◽

Vaccinium Ashei ◽

Freeze Damage ◽

Corroborative Evidence ◽

Better Than

Rabbiteye blueberry (Vaccinium ashei R.) flowers often suffer slight freeze damage that prevents fertilization and fruit development. To determine if gibberellic acid (GA3) might be useful in rescuing freeze-damaged flowers the following treatments were applied before anthesis to two cultivars at different locations: 1) undamaged control, 2) approximately two-thirds of the corolla and most of the style removed, 3) approximately half of the style removed, and 4) ovules lanced with an insect pin by driving it through the equator of the undeveloped berry until the point came out the other side. Half the bushes were not sprayed, and half were sprayed with GA3 (312 ppm, v/v) the night following treatment. `Climax' at Chula, Ga., had good fruit set for treatment 1 with and without GA3 (70% to 85%). Good fruit set also occurred for treatment 2, 3, and 4 where GA3 was applied (47% to 54%), but poor fruit set without GA3 (4% to 16%). `Tifblue' at Chula had significantly better fruit set for treatment 1 with GA3 (54% vs. 27%). Excellent fruit set occurred for treatment 2, 3, and 4 where GA3 was applied (81% to 96%), and poor fruit set without GA3 (6% to 7%). `Tifblue' fruit set by GA3 sized better than `Climax' fruit set by GA3. The experiments provide corroborative evidence that flowers that have suffered freeze damage to the stigma, style, corolla, and perhaps ovules can be set with GA3.

Download Full-text

Effect of GA3 Bloom Sprays on Fruit Set and Yield of Rabbiteye Blueberry

HortScience ◽

10.21273/hortsci.30.4.853d ◽

1995 ◽

Vol 30 (4) ◽

pp. 853D-853 ◽

Cited By ~ 1

Author(s):

J.G. Williamson ◽

R.L. Darnell ◽

G. Krewer ◽

S. NeSmith

Keyword(s):

Fruit Development ◽

Field Experiments ◽

Fruit Set ◽

Fruit Size ◽

Fruit Weight ◽

Night Temperature ◽

Vaccinium Ashei ◽

Hand Pollination ◽

Southern Georgia

Field and growth chamber experiments, and grower trials, were conducted to determine the effects of GA3 sprays on yield and fruit quality of rabbiteye blueberry (Vaccinium ashei Reade) in northern Florida and southern Georgia. Multiple GA3 sprays at various stages of flower development increased fruit set and yield in field experiments (Florida) and grower trials (Georgia) when compared to controls. Nonpollinated rabbiteye flowers sprayed with GA3 had greater percent fruit set and delayed fruit development compared to hand pollination. Percent fruit set and average fruit weight were reduced at 21C night temperature when compared to 10C night temperature for both hand-pollinated and GA3-treated fruit. Overall, yields were increased by multiple applications of GA3 during bloom, but average fruit size was reduced and the fruit development period was lengthened.

Download Full-text

Tomato progenies selection in Rondônia, Brazil

Horticultura Brasileira ◽

10.1590/s0102-053620190117 ◽

2019 ◽

Vol 37 (1) ◽

pp. 106-111

Author(s):

Maria José Marques ◽

Juliana de Fátima Vizú ◽

Danilo F da Silva Filho ◽

César Augusto Ticona-Benavente

Keyword(s):

Significant Variation ◽

Fruit Set ◽

Block Design ◽

Fruit Size ◽

Seed Mass ◽

The State ◽

Soluble Solids ◽

Randomized Block Design ◽

Pericarp Thickness ◽

Fruit Mass

ABSTRACT This study aimed to select endogamic progenies of tomato cv. Yoshimatsu and to conduct a progeny test in the state of Rondônia. The experiment was carried out in a randomized block design with four replicates and eight plants per plot, spacing 1x0.5 m, with one stem. A significant variation was observed among the fifteen progenies for productivity (2.0-5.5 kg plant-1), seed mass with placenta (18-31.5 g fruit-1), number of fruits per plant (18.8-38.7) and soluble solids (3.4-4.2°Brix). No significant variation was noticed for fruit size, pericarp thickness, number of locules, pH, number of flowers and fruit set, though. P6 progeny showed to be the most productive one (110 t ha-1): average fruit mass was 142.5 g, salad type tomato, 7.5 locules, 3.5°Brix, pH 4.2, 60.9 flowers per plant and 64.2% fruit set. Thus, these data show genetic variability of cultivar Yoshimatsu, being possible to obtain lines and/or cultivars with medium to large fruits adapted to the state of Rondônia.

Download Full-text

Effect of blossom thinning on fruit density, fruit size and seed count of Williams' Bon Chretien and Packham's Triumph pears

Australian Journal of Experimental Agriculture ◽

10.1071/ea9710248 ◽

1971 ◽

Vol 11 (49) ◽

pp. 248 ◽

Cited By ~ 1

Author(s):

A Selimi

Keyword(s):

Fruit Set ◽

Fruit Size ◽

Seed Number ◽

Cross Pollination ◽

Hand Pollination ◽

Bud Removal

Effects on fruit density, fruit size, and fruit fertilization (seed count) of several degrees of fruit bud removal three to four weeks before bloom, was studied on Williams Bon Chretien and Packham's Triumph pears. The effects were studied in the presence or absence of cross pollination. Fruit set increased with increasing severity of blossom bud removal, indicating that poor setting was not due to faulty flowers. This was also confirmed by hand pollination of the clusters on unthinned limbs, where fruit set was much higher than on unthinned unpollinated limbs. Fruit density in Packham's was not reduced even by 80 per cent of fruit bud removal, and in Williams' fruit density was significantly reduced at 60 or 40 per cent of fruit bud removal, in a heavy or intermediate flowering years, respectively, whereas in a poor flowering year, fruit density was not significantly reduced even by 80 per cent of bud removal. Heavy thinning resulted in increased fruit size in Williams' but not in Packham's pears. Hand poIlination or bouquets increased seed number and fruit size greatly in \Villiams7 and increased seed number but not fruit size in Packham's.

Download Full-text

Net Enclosure of ‘Honeycrisp’ and ‘Gala’ Apple Trees at Different Bloom Stages Affects Fruit Set and Alters Seed Production

Agronomy ◽

10.3390/agronomy9090478 ◽

2019 ◽

Vol 9 (9) ◽

pp. 478 ◽

Cited By ~ 4

Author(s):

Mokhles Elsysy ◽

Sara Serra ◽

Phil Schwallier ◽

Stefano Musacchi ◽

Todd Einhorn

Keyword(s):

Seed Production ◽

Fruit Set ◽

Insect Pests ◽

Fruit Size ◽

Quality Attributes ◽

Parthenocarpic Fruit ◽

Apple Trees ◽

Apple Production ◽

Commercial Crop ◽

Mature Seeds

Thinning is a critical but challenging practice in apple production, especially for organic producers. The objective of this experiment was to determine if exclusion netting, used to manage insect pests and stress, could reduce fruit set and thinning requirements of ‘Gala’ and ‘Honeycrisp’ apple trees in Michigan and Washington, U.S.A., respectively. Nets were closed around whole canopies at different timings based on a predetermined percentage of open flowers. In 2017 and 2018, netted trees set a full commercial crop regardless of percentage of open bloom at the time of netting, including prebloom enclosures. Fruit set and yield of netted ‘Honeycrisp’ trees were significantly lower than non-netted, nonthinned controls but similar to non-netted hand-thinned controls. ‘Gala’ fruit set and yield did not differ among treatments. Exclusion netting markedly reduced the number of mature seeds and increased the number of nonfertilized seeds in both cultivars. Pollinator exclusion to ‘Gala’ in a frost year increased parthenocarpic fruit set two-fold compared to non-netted trees. Fruit size, shape, and quality attributes of ‘Gala’ were were similar among treatments, but ‘Honeycrisp’ fruit were significantly smaller than hand-thinned, non-netted controls. Netting may constitute an alternative, viable strategy to manage fruit set but requires testing on different cultivars.

Download Full-text

Interspecific and Intraspecific Pollination Effects in Rabbiteye and Southern Highbush Blueberry

HortScience ◽

10.21273/hortsci.29.4.324 ◽

1994 ◽

Vol 29 (4) ◽

pp. 324-326 ◽

Cited By ~ 17

Author(s):

Creighton L. Gupton ◽

James M. Spiers

Keyword(s):

Fruit Development ◽

Fruit Set ◽

Highbush Blueberry ◽

Blue Ridge ◽

Vaccinium Ashei ◽

Berry Weight ◽

Cape Fear ◽

Southern Highbush ◽

Number Of Seeds ◽

Partial Diallel

To determine the effects of pollen source on blueberry production, we made a partial diallel set of crosses involving seven rabbiteye (Vaccinium ashei Reade) and seven southern highbush (SH; V. corymbosum L.) parents. Pollination of rabbiteye blueberry flowers with SH pollen reduced fruit set, seeds per berry, and berry weight and increased fruit development period (FDP) compared to pollination with rabbiteye pollen. Pollination of SH flowers with rabbiteye pollen resulted in about the same fruit set and FDP but fewer seeds per berry and slightly lower berry weight compared to intraspecific pollination. Self-pollination significantly decreased the number of seeds per berry and berry weight and increased FDP in SH. Pollination of rabbiteye and SH flowers with mixed pollen produced the same results as intraspecific pollination. Using `Tifblue' and `Baldwin' (rabbiteye) as the pollen parent significantly increased FDP in rabbiteye blueberry. Using `Georgiagem' and `Cape Fear' as pollen parents produced the longest FDP, and using `O'Neal' and `Gulfcoast' produced the shortest FDP in SH blueberry. The heaviest berries were produced by using `Blue Ridge', `O'Neal', and `Gulfcoast' (SH) as pollen parents on SH females. These results suggest that xenia possibly could be used to increase yield and reduce FDP in blueberry.

Download Full-text

Prebloom Treatments to Alleviate Cold Injury in Apple

HortScience ◽

10.21273/hortsci.30.4.807e ◽

1995 ◽

Vol 30 (4) ◽

pp. 807E-807

Author(s):

E.W. Stover ◽

T.E. Paine ◽

W.C. Stiles

Keyword(s):

Leaf Area ◽

Untreated Control ◽

Fruit Set ◽

Fruit Size ◽

Cold Injury ◽

Seed Number ◽

Flower Buds ◽

Active Growth ◽

Strong Trend ◽

Winter Temperatures

Damage to xylem subtending apple buds is often observed following very low winter temperatures. Reports suggest that prebloom application of boron, zinc, and urea facilitate recovery. Prebloom nutrient treatments were applied to `McIntosh' and `Empire' at three sites in Spring 1994. The following treatments were applied to drip at half-inch green: boron (22.8 mM, solubor); Zn-EDTA (0.75 mM); boron and Zn-EDTA; boron, Zn-EDTA, and urea (59.4 mM). Another treatment used boron and Zn-EDTA at half-inch green, followed by boron, Zn-EDTA, and urea at pink. Spur leaf area, fruit set, fruit size, and seed number were determined. There were no clear treatment effects at the warmest site (mid-winter low –32C); however, this orchard was more variable than other treatment sites. The intermediate site (mid-winter low –37C) had a strong trend of increasing fruit set in `Empire' and `McIntosh' as more nutrients were applied. The combined half-inch green and pink treatment significantly increased fruit set by 23.8% compared to the untreated control. At the coldest site (mid-winter low –42C), `Empire' again displayed a strong trend of increasing fruit set with additional nutrients. All treatments combining boron and zinc significantly increased fruit set. The combined half-inch green and pink treatment increased fruit set by 43%. At this site `McIntosh' did not respond to treatment. However, `McIntosh' trees had continued active growth into late Fall 1993 and sustained severe cold injury in November. Data suggest that, when they were effective, nutrient treatments resulted in increased retention of flower buds on damaged spurs.

Download Full-text

Effective Pollination Period of Actinidia chinensis ‘AU Golden Sunshine’ and A. deliciosa ‘AU Fitzgerald’ Kiwifruit

HortScience ◽

10.21273/hortsci13617-18 ◽

2019 ◽

Vol 54 (4) ◽

pp. 656-660

Author(s):

Ashley K. Brantley ◽

James D. Spiers ◽

Andrew B. Thompson ◽

James A. Pitts ◽

J. Raymond Kessler ◽

...

Keyword(s):

Fruit Set ◽

Linear Trend ◽

Fruit Size ◽

Fruit Weight ◽

Open Pollination ◽

Seed Number ◽

Alternate Bearing ◽

Size Index ◽

Days After Anthesis ◽

Female Flowers

Commercial kiwifruit production often requires substantial inputs for successful pollination. Determining the length of time that female flowers can be successfully pollinated can aid management decisions concerning pollination enhancement. The purpose of this research was to determine the effective pollination period (EPP) for ‘AU Golden Sunshine’ and ‘AU Fitzgerald’. Either 30 (2013) or 32 (2014, 2015) flowers of ‘AU Golden Sunshine’ were hand pollinated each day for 1 to 5 (2013) days after anthesis (DAA) or 1 to 7 DAA (2014, 2015), and then isolated to prevent open pollination. Anthesis was considered the day the flower opened. Similarly, ‘AU Fitzgerald’ flowers were pollinated and then isolated 1 to 6 DAA in 2013 and 1 to 7 DAA in 2015. For ‘AU Golden Sunshine’ in 2013, fruit set was consistent over the 5-day period, but fruit weight, fruit size index, and seed number decreased between 1 and 3 and 4 and 5 DAA. In 2014, fruit set decreased between 1 and 6 and 7 DAA, whereas fruit weight, fruit size index, and seed number each decreased in a linear trend. In 2015, fruit set also decreased between 1 and 6 and 7 DAA, whereas all other responses decreased linearly. Based on fruit set in 2014 and 2015, the EPP for ‘AU Golden Sunshine’ was 6 DAA. The EPP for ‘AU Fitzgerald’, however, was more variable. In 2013, fruit weight, fruit size index and seed number decreased between 1 and 4 and 5 and 6 DAA, suggesting that the EPP was 4 DAA. In 2015, fruit set remained consistent over the 7-day period with fruit weight, fruit size index, and seed number decreasing linearly. Differences in temperature and the alternate bearing tendency of kiwifruit species likely contributed to the discrepancies between the years for the EPP. For each cultivar, reductions in fruit weight, size, and seed number were observed before an observed decrease in fruit set. Greater fruit weight, size, and seed number were observed when flowers were pollinated within the first few DAA, with results varying thereafter.

Download Full-text