scholarly journals 530 Fruitfulness of Evergreen vs. Deciduous Southern Highbush Blueberry after Cross-, Self-, and No Pollination

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 537B-537
Author(s):  
Ingrith D. Martinez ◽  
P.M. Lyrene
Keyword(s):  
Seed Production ◽  
Fruit Set ◽  
Fruit Size ◽  
Management Systems ◽  
Highbush Blueberry ◽  
Seed Number ◽  
Dormant Period ◽  
Mature Leaves ◽  
Hand Pollination ◽  
Southern Highbush

Fruit set, fruit size, and seed production after hand pollination in a greenhouse were compared for southern highbush blueberry managed in two ways: a) 69 clones were allowed to go dormant and lose their leaves in the field before being dug and subjected to 1000 hours at 5 °C and b) 26 clones were kept growing in a greenhouse through fall and winter without leaf loss and without chilling, to induce flowering on plants that had mature leaves. On each plant in both management systems, some flowers were self-pollinated, some were cross-pollinated, and others had the styles removed before anthesis to prevent pollination. For >1000 flowers per pollination treatment on the deciduous plants, fruit set averaged 1% for no pollination, 46% for self-pollination, and 76% for cross-pollination. The corresponding values for the evergreen plants were 23%, 59%, and 81%. Parthenocarpic berries averaged 0.37 g/berry for deciduous plants and 1.01 g for evergreen plants. Both crossed and selfed berry weights averaged slightly higher for the evergreen plants than for the deciduous plants, but seed number per berry was much lower for the evergreen plants (12 seeds in crossed berries and four seeds in selfed berries) compared to deciduous plants (37 and 8). Southern highbush blueberry plants that flower without going dormant appear to have much higher parthenocarpic capabilities than those that flower after a dormant period.

scholarly journals Impact of Cross- and Self-pollination on Fruit Set, Fruit Size, Seed Number, and Harvest Timing Among 13 Southern Highbush Blueberry Cultivars

2016 ◽  
Vol 26 (2) ◽  
pp. 213-219 ◽  
Author(s):  
Sarah K. Taber ◽  
James W. Olmstead
Keyword(s):  
Fruit Set ◽  
Fruit Size ◽  
Vaccinium Corymbosum ◽  
Fruit Weight ◽  
High Yield ◽  
Highbush Blueberry ◽  
Seed Number ◽  
Cross Pollination ◽  
Self Pollination ◽  
Southern Highbush

Cross-pollination has been associated with improved fruit set, weight, and shortened time to ripening in southern highbush blueberry [SHB (Vaccinium corymbosum interspecific hybrids)]. Because of this, growers commonly plant two or more cultivars in small blocks to facilitate cross-pollination. However, many SHB cultivars may vary in the degree of improvement in each parameter after cross-pollination. Understanding the impacts of cross-pollination on a particular cultivar is crucial to forming planting recommendations, particularly as growers begin to transition to fields designed for machine harvest where large solid blocks would increase the harvest efficiency. The objective of this study was to examine the effects of cross- and self-pollination among 13 commonly planted or newly released SHB cultivars. Cross-pollination typically improved fruit set, fruit weight, and seed number while decreasing the average days to harvest. Cross-pollinated fruit always weighed more than self-pollinated fruit from the same cultivar, which was highly correlated to seed number per fruit. Although there was variation for each trait, interplanting with another unrelated cultivar sharing a similar bloom time remains the best recommendation to ensure early, high yield among these SHB cultivars.

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

1971 ◽  
Vol 11 (49) ◽  
pp. 248 ◽  
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.

scholarly journals Effects of CPPU on Fruit Size, Set, and Yield of Southern Highbush Blueberry in Florida

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 793A-793
Author(s):  
Jeffrey G. Williamson* ◽  
E. Paul Miller
Keyword(s):  
Fruit Ripening ◽  
Fruit Set ◽  
Fruit Size ◽  
Vaccinium Corymbosum ◽  
Limiting Factors ◽  
Highbush Blueberry ◽  
Fresh Weight ◽  
Full Bloom ◽  
Berry Size ◽  
Southern Highbush

Poor fruit set and sub-optimum berry size are potential yield- and profit-limiting factors for southern highbush (Vaccinium corymbosum) blueberry production in Florida. The cytokinin N-(2-chloro-4-pyridyl)-N'-phenylurea (CPPU) has increased fruit size and fruit set of a number of fruit crops including rabbiteye blueberry. The purpose of this study was to determine the effects of CPPU applied at different rates and phenological stages of bloom and/or fruit development on fruit size, set, and yield of southern highbush blueberry. `Millennia' and `Star' southern highbush blueberry plants located on a commercial blueberry farm in Alachua County, Fla., were treated with 5 or 10 ppm CPPU at various stages of development ranging from full bloom to 20 days after full bloom. In contrast to findings with rabbiteye blueberry, fruit set in this study of southern highbush blueberry was not affected by any of the CPPU treatments when compared to the controls. Nor was total fruit yield affected by CPPU treatments. The most noticeable potential benefit found in this study was an increase in mean fruit fresh weight from CPPU treatments. However, cultivars responded differently to CPPU with respect to mean fruit fresh weight. For `Millennia', only one CPPU treatment increased mean fruit weight compared to controls. However, for `Star', all but one CPPU treatment increased mean fruit fresh weight. Several CPPU treatments resulted in delayed fruit ripening for `Star' but not for `Millennia'. For `Star', the treatments that most consistently delayed fruit ripening tended to have greater fruit fresh weights.

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

Agronomy ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 478 ◽  
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.

scholarly journals Interspecific and Intraspecific Pollination Effects in Rabbiteye and Southern Highbush Blueberry

HortScience ◽  
1994 ◽  
Vol 29 (4) ◽  
pp. 324-326 ◽  
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.

scholarly journals Prebloom Treatments to Alleviate Cold Injury in Apple

HortScience ◽  
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.

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

HortScience ◽  
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.

scholarly journals Flower Bud Density Affects Vegetative and Fruit Development in Field-grown Southern Highbush Blueberry

HortScience ◽  
1999 ◽  
Vol 34 (4) ◽  
pp. 607-610 ◽  
Author(s):  
B.E. Maust ◽  
J.G. Williamson ◽  
R.L. Darnell
Keyword(s):  
Leaf Area ◽  
Fruit Development ◽  
Fruit Size ◽  
Dry Weight ◽  
Vaccinium Corymbosum ◽  
Soluble Solids ◽  
Highbush Blueberry ◽  
Flower Buds ◽  
Flower Bud ◽  
Southern Highbush

Floral budbreak and fruit set in many southern highbush blueberry (SHB) cultivars (hybrids of Vaccinium corymbosum L. with other species of Vaccinium) begin prior to vegetative budbreak. Experiments were conducted with two SHB cultivars, `Misty' and `Sharpblue', to test the hypothesis that initial flower bud density (flower buds/m cane length) affects vegetative budbreak and shoot development, which in turn affect fruit development. Flower bud density of field-grown plants was adjusted in two nonconsecutive years by removing none, one-third, or two-thirds of the flower buds during dormancy. Vegetative budbreak, new shoot dry weight, leaf area, and leaf area: fruit ratios decreased with increasing flower bud density in both cultivars. Average fruit fresh weight and fruit soluble solids decreased in both cultivars, and fruit ripening was delayed in `Misty' as leaf area: fruit ratios decreased. This study indicates that because of the inverse relationship between flower bud density and canopy establishment, decreasing the density of flower buds in SHB will increase fruit size and quality and hasten ripening.

scholarly journals Hydrogen Cyanamide Stimulates Early Foliation of `Misty' Southern Highbush Blueberry

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 537C-537
Author(s):  
J.G. Williamson ◽  
R.L. Darnell
Keyword(s):  
Vegetative Growth ◽  
Fruit Set ◽  
Small Diameter ◽  
Highbush Blueberry ◽  
Full Bloom ◽  
Flower Buds ◽  
Flower Bud ◽  
Hydrogen Cyanamide ◽  
Southern Highbush ◽  
Chilling Treatment

Two-year-old, container-grown `Misty' southern highbush blueberry plants were sprayed to drip with two concentrations of hydrogen cyanamide (HCN) (20.4 g·L–1 and 10.2 g·L–1) after exposure to 0, 150, or 300 hr of continuous chilling at 5.6°C. All plants were sprayed immediately after chilling and placed in a greenhouse for several weeks. The plants were moved outdoors during flowering to increase cross-pollination from nearby `Sharpblue' blueberry plants. HCN sprays killed some of the more advanced flower buds on shoot terminals and on small-diameter wood from the previous spring growth flush. Significantly greater flower bud mortality occurred for the 20.4 g·L–1 HCN sprays than for the 10.2 g·L–1 sprays. Flower buds subjected to 0 hr of chilling were more susceptible to spray burn than flower buds receiving 150 or 300 hr of chilling. Very little flower bud death occurred with the 10.2 g·L–1 HCN rate on plants receiving 300 hr of chilling. Vegetative budbreak was advanced for both HCN treatments compared to controls, regardless of chilling treatment. HCN-treated plants were heavily foliated at full bloom, while non-treated plants had very few to no leaves during bloom. HCN may be useful for stimulating vegetative growth in some southern highbush blueberry cultivars that suffer from poor foliation during flowering and fruit set.

The beneficial effect of ants on the reproductive success of Dyckia floribunda (Bromeliaceae), an extrafloral nectary plant

2003 ◽  
Vol 81 (1) ◽  
pp. 24-27 ◽  
Author(s):  
José L Vesprini ◽  
Leonardo Galetto ◽  
Gabriel Bernardello
Keyword(s):  
Seed Production ◽  
Reproductive Output ◽  
Fruit Set ◽  
Seed Set ◽  
Reproductive Organs ◽  
Extrafloral Nectaries ◽  
Perennial Herb ◽  
Seed Number ◽  
Total Seed ◽  
Mutualistic Association

Dyckia floribunda is a perennial herb from the Argentinian Chaco with extrafloral nectaries. Ants visited these nectaries while patrolling inflorescences and infructescences. We anticipated that ants attracted to extrafloral nectaries might protect the reproductive organs, increasing plant reproductive output. To evaluate the possibility of mutualism between D. floribunda and ant visitors, we determined whether ant-accessible plants showed a higher seed production than ant-excluded plants. Experimental fieldwork suggested a decrease in fruit set of ant-excluded plants compared with ant-accessible plants but the seed number per fruit was not affected by ant exclusion. Thus, total seed number per plant was highly reduced in treated spikes. Analyses of covariance confirmed these trends, indicating that total seed production per plant was strongly affected by ant exclusion. This study marks the first experimental report of this mutualistic association in Bromeliaceae.Key words: ant–plant interaction, Bromeliaceae, Chaco, Dyckia floribunda, fruit set, seed set, mutualism.

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