Adding bumblebees (Bombus terrestrisL., Hymenoptera: Apidae) to pear orchards increases seed number per fruit, fruit set, fruit size and yield

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.

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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.

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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.

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Effect of pollinators on fruit set, fruit size and seed numbers of Early Imperial and Ellendal mandarins

Australian Journal of Experimental Agriculture ◽

10.1071/ea9700644 ◽

1970 ◽

Vol 10 (46) ◽

pp. 644

Author(s):

LM Stafford

Keyword(s):

Fruit Set ◽

Fruit Size ◽

Seed Number ◽

Valencia Orange

At Mildura, Victoria, fruit set and fruit size of two mandarin cultivars Early Imperial (C. reticulata Blanco) and Ellendale (C. reticulata X C. sinensis (L) Osbeck) were improved when randomly selected twigs were hand cross-pollinated. Pollinators used with Early Imperial mandarin (1966-67) were mandarin cultivars Emperor and Ellendale. In comparison with self pollinated twigs, both pollinators more than doubled percentage set and mean seed number and increased fruit size. Pollinators used with Ellendale mandarin (1967-68) were the mandarin cultivars Early Imperial and Emperor, and Valencia orange (C. sinensis (L) Osbeck). All cross pollinators quadrupled percentage set, more than doubled seed number and increased fruit size.

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

HortTechnology ◽

10.21273/horttech.26.2.213 ◽

2016 ◽

Vol 26 (2) ◽

pp. 213-219 ◽

Cited By ~ 4

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.

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

HortScience ◽

10.21273/hortsci.34.3.537b ◽

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.

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Testing a Power Duster for Pollination of `McIntosh' Apples

HortScience ◽

10.21273/hortsci.32.3.473d ◽

1997 ◽

Vol 32 (3) ◽

pp. 473D-473

Author(s):

J.R. Schupp ◽

S.I. Koller ◽

W.D. Hosmer

Keyword(s):

Fruit Set ◽

Fruit Size ◽

Limiting Factor ◽

Seed Number ◽

Apple Trees ◽

Supplemental Pollination

This study was undertaken to test the efficacy of a power duster for supplemental pollination of `McIntosh' apple trees, where lack of nearby pollinizing cultivars was thought to be a limiting factor to productivity. The pollen duster was ineffective in increasing fruit set, fruit size, or seed number in fruits on limbs that were covered with spun-bonded rowcover material prior to bloom. Applying supplemental pollen to open-pollinated `McIntosh' trees had no effect on fruit set, yield, fruit size, or seed number, regardless of pollen dose, timing, or number of applications. Dispersal of supplemental pollen with a power duster appears to be an inefficient method of pollinating apple trees.

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184 Timing of Benzyladenine Application as a Chemical Thinner of `Empire' Apple

HortScience ◽

10.21273/hortsci.29.5.455d ◽

1994 ◽

Vol 29 (5) ◽

pp. 455d-455 ◽

Cited By ~ 1

Author(s):

V. E. Emongor ◽

D. P. Murr

Keyword(s):

Fruit Quality ◽

Ethylene Production ◽

Fruit Set ◽

Fruit Size ◽

Fruit Weight ◽

Seed Number ◽

Full Bloom ◽

Apple Trees ◽

Effective Time ◽

Fruit Diameter

Benzyladenine (100 or 200 mg.litre-1) was applied to mature Empire/M.26 apple trees as dilute sprays 2, 4, 9, 11, 13, 15, 17, 20, 25, 27, 29 or 31 days after full bloom (DAFB). The most effective time of thinning was 25-29 DAFB (king fruit diameter 8.94-13.91 mm), and the thinning response to BA concentration was linear. Benzyladenine (BA) did not reduce fruit set when king fruit diameter was less than 5.35 mm, but BA significantly increased fruit weight, diameter (D), length (L) and L:D ratio compared to unsprayed controls and later BA treatments. BA - treated fruitlets had higher ethylene production, 24 hours and 7 days after spraying compared to untreated controls. We suggest that the response of apple fruitlets to BA applied as a thinner is mediated by ethylene. High fruit quality was obtained when BA was applied at 17-31 DAFB. Timing of BA sprays had no effect on seed number, though BA significantly increased seed number, fruit size, weight and L:D ratio. These results suggest that BA has the potential to substitute for the use of carbaryl as a thinner of apples in Ontario orchards.

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Effect of Benzyladenine (BA) on Fruit Thinning and Carbohydrate Status in Apples

HortScience ◽

10.21273/hortsci.32.3.525d ◽

1997 ◽

Vol 32 (3) ◽

pp. 525D-525

Author(s):

Rongcai Yuan ◽

Duane W. Greene

Keyword(s):

Fruit Set ◽

Dark Respiration ◽

Fruit Size ◽

Net Photosynthesis ◽

Seed Abortion ◽

Seed Number ◽

Fruit Thinning ◽

Control Fruit ◽

Viable Seeds ◽

Carbohydrate Status

BA applied at the 10-mm stage at 50 and 100 ppm thinned, increased fruit size, and seed abortion. Net photosynthesis was decreased and dark respiration was increased when temperature following BA application was high (30°C), whereas there was no effect when temperature was lower (20°C). The seed number in abscising fruit was greater in BA-treated fruit than in control fruit. The number of viable seeds in BA-treated fruit was reduced. Tipping the bourse shoot increased fruit set, regardless of BA treatment. BA did not thin fruit with 25 leaves or greater. The translocation of 14C-sorbital from leaves to fruit was promoted by BA application to the fruit, but not when BA was applied to the leaves. The thinning induced by BA will be discussed in relation to available carbohydrate.

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

HortScience ◽

10.21273/hortsci.33.4.632 ◽

1998 ◽

Vol 33 (4) ◽

pp. 632-635 ◽

Cited By ~ 7

Author(s):

Raquel Cano-Medrano ◽

Rebecca L. Darnell

Keyword(s):

Gibberellic Acid ◽

Fruit Development ◽

Fruit Set ◽

Fruit Size ◽

Seed Mass ◽

Parthenocarpic Fruit ◽

Seed Number ◽

Vaccinium Ashei ◽

Development Period ◽

Fruit Mass

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).

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