Hydrogen Cyanamide Accelerates Vegetative Budbreak and Shortens Fruit Development Period of Blueberry

Experiments were conducted in north Florida and south Georgia to determine the effects of H2CN2 sprays on vegetative and reproductive growth of blueberry. In Florida, mature, field-grown `Misty' southern highbush (Vaccinium corymbosum L. hybrid) blueberry plants were sprayed to drip with 0, 10.2, or 20.4 g·L-1 of H2CN2 [hereafter referred to as 0%, 1.0%, and 2.0% (v/v) H2CN2] on 20 Dec. 1996 and 7 Jan. 1997. During the following winter, mature `Misty' southern highbush and `Climax' rabbiteye (V. ashei Reade) plants were sprayed to drip with 0, 7.6, or 15.3 g·L-1 of H2CN2 [hereafter referred to as 0%, 0.75%, and 1.5% (v/v) H2CN2] on 17 Dec. 1997 and 6 Jan. 1998. For all experiments, plants were dormant and leafless, with slightly swollen flower buds, at the time of spray applications. Generally, H2CN2 sprays increased the extent and earliness of vegetative budbreak and canopy establishment and advanced flowering slightly. The number of vegetative budbreaks usually increased linearly with increasing spray concentrations. In Florida, H2CN2 [0.75% to 1.0% (v/v)] sprays increased mean fruit fresh weight and yield, and shortened the fruit development period (FDP) compared to controls. However, H2CN2 sprays ranging in concentration from 1.5% to 2.0% (v/v) resulted in significant flower bud injury and reduced total fruit yield compared to controls. In south Georgia, 27 of 37 field trials conducted between 1991 and 1998 on several rabbiteye and southern highbush cultivars indicated that leaf development was significantly enhanced by H2CN2. H2CN2 shows potential for increasing early fruit maturity, fruit size, and yield of southern highbush and rabbiteye blueberry cultivars with poor leaf development characteristics in low-chill production regions. Chemical name used: hydrogen cyanamide (H2CN2).

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

HortScience ◽

10.21273/hortsci.34.4.607 ◽

1999 ◽

Vol 34 (4) ◽

pp. 607-610 ◽

Cited By ~ 17

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.

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Hydrogen Cyanamide Increases Leafing and Reduces Fruit Development Period of Southern Highbush Blueberry

HortScience ◽

10.21273/hortsci.33.3.529c ◽

1998 ◽

Vol 33 (3) ◽

pp. 529c-529

Author(s):

J.G. Williamson ◽

B.E. Maust ◽

R.L. Darnell

Keyword(s):

Fruit Development ◽

Fruit Size ◽

Highbush Blueberry ◽

Flower Bud ◽

North Central ◽

Hydrogen Cyanamide ◽

Central Florida ◽

Fruit Thinning ◽

Fruit Maturity ◽

Southern Highbush

Mature, field-grown `Misty' southern highbush blueberry plants were sprayed to drip with 0, 20.4, and 10.2 g·L–1 concentrations of hydrogen cyanamide in north-central Florida on 20 Dec. and 7 Jan. 1996–97. Plants were dormant and leafless, with slightly swollen flower buds, at the time of spray applications. All hydrogen cyanamide sprays increased the extent and earliness of vegetative budbreak and canopy establishment. The number of vegetative budbreaks per centimeter of shoot length increased linearly with increasing spray concentration of hydrogen cyanamide. Hydrogen cyanamide-treated fruit had greater average fresh weights and shorter average fruit development periods than non-treated fruit. On 15 Apr., 40% ti 60% of hydrogen cyanamide-treated fruit were ripe compared to about 10% of control fruit. Some flower bud damage and subsequent fruit thinning was observed from the 20.4 g·L–1 spray, especially at the later spray date. Hydrogen cyanamide shows potential for increasing early fruit maturity and fruit size of some southern highbush blueberry cultivars in Florida.

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Comparative anatomical and transcriptomic insights into Vaccinium corymbosum flower bud and fruit throughout development

BMC Plant Biology ◽

10.1186/s12870-021-03067-6 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Li Yang ◽

Liangmiao Liu ◽

Zhuoyi Wang ◽

Yu Zong ◽

Lei Yu ◽

...

Keyword(s):

Fruit Development ◽

Fruit Size ◽

Size Variation ◽

Signal Transduction Pathway ◽

Vaccinium Corymbosum ◽

Flower Bud ◽

Large Size ◽

Underlying Mechanisms ◽

Southern Highbush ◽

Signal Transductions

Abstract Background Blueberry (Vaccinium spp.) is characterized by the production of berries that are smaller than most common fruits, and the underlying mechanisms of fruit size in blueberry remain elusive. V. corymbosum ‘O’Neal’ and ‘Bluerain’ are commercial southern highbush blueberry cultivars with large- and small-size fruits, respectively, which mature ‘O’Neal’ fruits are 1 ~ 2-fold heavier than those of ‘Bluerain’. In this study, the ontogenetical patterns of ‘O’Neal’ and ‘Bluerain’ hypanthia and fruits were compared, and comparative transcriptomic analysis was performed during early fruit development. Results V. corymbosum ‘O’Neal’ and ‘Bluerain’ hypanthia and fruits exhibited intricate temporal and spatial cell proliferation and expansion patterns. Cell division before anthesis and cell expansion after fertilization were the major restricting factors, and outer mesocarp was the key tissue affecting fruit size variation among blueberry genotypes. Comparative transcriptomic and annotation analysis of differentially expressed genes revealed that the plant hormone signal transduction pathway was enriched, and that jasmonate-related TIFYs genes might be the key components orchestrating other phytohormones and influencing fruit size during early blueberry fruit development. Conclusions These results provided detailed ontogenetic evidence for determining blueberry fruit size, and revealed the important roles of phytohormone signal transductions involving in early fruit development. The TIFY genes could be useful as markers for large-size fruit selection in the current breeding programs of blueberry.

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526 Hydrogen Cyanamide Hastens Fruit Development and Increases Fruit Yield and Berry Size of Blueberry

HortScience ◽

10.21273/hortsci.34.3.536c ◽

1999 ◽

Vol 34 (3) ◽

pp. 536C-536

Author(s):

J.G. Williamson ◽

E.P. Miller

Keyword(s):

Fruit Development ◽

Fruit Yield ◽

Yield Response ◽

Flower Bud ◽

North Central ◽

Hydrogen Cyanamide ◽

Central Florida ◽

Berry Size ◽

Southern Highbush ◽

The Times

Field-grown `Misty', `Star', and `Southmoon' southern highbush, and `Climax' rabbiteye blueberry plants were sprayed to drip with 0, 7.7 and 15.4 g·L–1 concentrations of hydrogen cyanamide in north central Florida on 17 Dec. 1997 and 6 Jan. 1998. Plants were dormant with slightly swollen flower buds (stage 2) at the times of applications. The extent and earliness of vegetative budbreak were increased by both hydrogen cyanamide sprays. Hydrogen cyanamide also increased mean fruit fresh weights and reduced fruit development periods for `Misty', `Southmoon' and `Climax' but not for `Star'. Yield response to hydrogen cyanamide was variable among cultivars. Fruit yields of `Misty' and `Climax' increased slightly by 7.7 g·L–1 sprays and decreased significantly by 15.4 g·L–1 sprays. In that case, increased fruit yields appeared to be the result of greater mean fruit fresh weights while reduced yields resulted from significant flower bud thinning that occurred at the highest spray concentration. Both hydrogen cyanamide spray concentrations increased fruit yield for `Southmoon' and decreased fruit yield for `Star' when compared to controls. Spray date had no effect on fruit yield and little effect on fruit development period. Hydrogen cyanamide has potential for increasing fruit quality and earliness of some blueberry cultivars that are grown in the lower southeastern United States.

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Effects of Flower Bud Density on Vegetative and Reproductive Development and Carbohydrate Relations in Southern Highbush Blueberry

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.124.5.532 ◽

1999 ◽

Vol 124 (5) ◽

pp. 532-538 ◽

Cited By ~ 5

Author(s):

B.E. Maust ◽

J.G. Williamson ◽

R.L. Darnell

Keyword(s):

Leaf Area ◽

Fruit Development ◽

Vaccinium Corymbosum ◽

Soluble Solids ◽

Highbush Blueberry ◽

Flower Bud ◽

Delay Reduction ◽

Canopy Development ◽

Carbohydrate Concentration ◽

Southern Highbush

Vegetative budbreak and subsequent canopy development in some southern highbush blueberry (Vaccinium corymbosum L. interspecific hybrid) cultivars are delayed and/or reduced as flower bud density increases. This delay/reduction in vegetative growth has been correlated with decreased weight and soluble solids of individual fruit. In the present study, the effects of flower bud density (FBD) on vegetative budbreak and canopy development, starch reserves, and whole-canopy net CO2 exchange rate (NCER) were assessed to determine how FBD affected the source supply for fruit development. A range of flower bud densities was established in two cultivars of containerized southern highbush blueberry during dormancy. Vegetative budbreak was delayed and vegetative budbreak, leaf area, and leaf area to fruit ratios decreased as FBD increased. In general, increasing FBD increased the rate of root and cane starch depletion during the first four weeks after bloom. Whole-canopy NCER was similar across the range of FBD during early fruit development, but between four weeks after bloom and fruit ripening, NCER decreased as FBD increased. Although FBD explained only a small proportion of the variability observed in carbohydrate concentration and NCER, the data suggest that both the rapid depletion of starch reserves early in fruit development and the decrease in whole canopy NCER later in fruit development contribute to the detrimental effects of increased FBD on fruit development.

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Blossom Thinning in Pome and Stone Fruit

HortScience ◽

10.21273/hortsci.33.3.553b ◽

1998 ◽

Vol 33 (3) ◽

pp. 553b-553

Author(s):

Esmaeil Fallahi

Keyword(s):

Fruit Size ◽

Naphthalene Acetic Acid ◽

Full Bloom ◽

Flower Bud ◽

Hydrogen Cyanamide ◽

Ammonium Thiosulfate ◽

The Past ◽

Apple Cultivars ◽

Ortho Cresol ◽

Bud Initiation

Early thinning of apples is important because of its impact on fruit size and next season's flower bud initiation. In the past, apple cultivars were often sprayed with the blossom thinner sodium dinitro-ortho-cresol(Elgetol) during full bloom, followed by a post-bloom application of a fruit thinner such as carbaryl with or without naphthalene acetic acid (NAA). Elgetol was removed from the market in 1989 because of the high cost of re-registration. Full-bloom sprays of sulfcarbamide (Wilthin), pelargonic acid (Thinex), and endothalic acid (Endothal), ammonium thiosulfate (ATS) or petal fall spray of carbaryl (Sevin XLR Plus) were developed as replacements for Elgetol. Hydrogen cyanamide (HC) and other chemicals have been used to eliminate or to reduce chilling requirements of peaches grown under the warm desert conditions. HC applied at “pink bloom” stage was observed to reduce the number of open blooms in `Florda Prince' peach; therefore, it was first used for blossom thinning in this cultivar in Arizona. Later, HC was also found to be an effective blossom thinner for plums in Idaho. HC has recently been found to effectively thin apple and peach blossoms. Armothin has also been an effective blossom thinner for peach in California.

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Enhanced Bud Production in Highbush Blueberry (Vaccinium corymbosum L.) in Response to Paclobutrazol

HortScience ◽

10.21273/hortsci.33.1.75 ◽

1998 ◽

Vol 33 (1) ◽

pp. 75-77 ◽

Cited By ~ 1

Author(s):

Mark K. Ehlenfeldt

Keyword(s):

Fruit Ripening ◽

Fruit Size ◽

Shoot Elongation ◽

Plant Size ◽

Vaccinium Corymbosum ◽

Highbush Blueberry ◽

Flower Bud ◽

Bud Formation ◽

Bud Set ◽

Determining Factor

Blueberry cultivars were treated with either soil drenches or foliar applications of paclobutrazol. Soil drenches of 25 mg·L-1 inhibited shoot elongation and stimulated earlier and greater flower bud production on `Bluetta', `Bluecrop', and `Jersey'. The treatments increased bud numbers 359% to 797%, and stimulated compound bud formation, while reducing formation of vegetative buds. This resulted in overcropping and reduced fruit size. Foliar applications at concentrations of 5, 10, 50, and 100 mg·L-1 increased bud set. Treatments did not significantly alter time to 50% flowering in `Bluecrop' or `Duke', but hastened flowering up to 5 days in `Blueray' at 200 ppm. Fruit ripening was significantly delayed at 100 and 200 ppm in `Bluecrop' due to overcropping, but no delays were observed in `Blueray' or `Duke'. Plant size and vigor appeared to be a determining factor in plant response. Chemical name used: PP333 or (2RS,3RS)-l(4-chlorophenyl)-4,4-dimethyl-2-(l,2,4-triazol-1-yl)pentan-3-ol (paclobutrazol).

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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.

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

HortScience ◽

10.21273/hortsci.32.3.537c ◽

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.

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Flower Bud Load Influences Blueberry Vegetative and Fruit Development

HortScience ◽

10.21273/hortsci.31.4.682e ◽

1996 ◽

Vol 31 (4) ◽

pp. 682e-682

Author(s):

B.E. Maust ◽

J.G. Williamson ◽

R.L. Darnell

Keyword(s):

Leaf Area ◽

Fruit Development ◽

Reproductive Development ◽

Dry Weight ◽

Highbush Blueberry ◽

Fresh Weight ◽

Flower Buds ◽

Flower Bud ◽

Fruit Maturity ◽

Southern Highbush

A field experiment was conducted in Gainesville, Fla., with two southern highbush blueberry cultivars, `Misty' and `Sharpblue', to investigate the influence of varying flower bud load on the timing and extent of vegetative and reproductive development. Flower bud load was adjusted on three different canes on ten plants by removing none, one-third, or two-thirds of the flower buds. Vegetative budbreak, leaf area, fruit number, and fruit fresh weight and dry weight were measured. Vegetative budbreak was delayed with increasing flower bud load. Vegetative budbreak, leaf area, and leaf area: fruit ratio decreased with increasing flower bud load. Fruit maturity was delayed and average berry fresh weight and dry weight declined with decreasing leaf area:fruit ratio. Responses were similar for both cultivars although `Misty' was more adversely affected by high flower bud load and low leaf area: fruit ratio.

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