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

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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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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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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Flower and Fruit Load Influence Blueberry Plant Development and CO2 Exchange Rate

HortScience ◽

10.21273/hortsci.32.3.443a ◽

1997 ◽

Vol 32 (3) ◽

pp. 443A-443

Author(s):

B.E. Maust ◽

J.G. Williamson ◽

R.L. Darnell

Keyword(s):

Exchange Rate ◽

Leaf Area ◽

Fruit Ripening ◽

Highbush Blueberry ◽

Plant Canopy ◽

Flower Buds ◽

Flower Bud ◽

Whole Plant ◽

Southern Highbush ◽

Fruit Load

Two southern highbush blueberry cultivars, `Sharpblue' and `Misty', were used to investigate the influence of varying flower bud density and fruit load on vegetative development, whole-plant canopy CO2 exchange rate (CER), and leaf CER. Plants were grown in pots and flower buds were removed so that initial flower bud density (fl ower bud number/total cane length) on a whole-plant basis ranged from 0.05–0.35 flower buds/cm. Vegetative budbreak number, leaf area, and leaf area: fruit ratio decreased with increasing flower bud density. In `Sharpblue', whole-plant canopy CER measured at fruit ripening decreased with increasing flower and fruit load and decreasing leaf area:fruit ratio, while leaf CER increased with increasing fruit load and decreasing leaf area:fruit ratio. In `Misty', whole-plant canopy CER measured 4 weeks after full bloom decreased with increasing flower and fruit load, but whole-plant canopy and leaf CER at fruit ripening were similar among the different fruit loads. Average fruit fresh and dry weights increased and the fruit development period decreased with increased leaf area:fruit ratio in both cultivars. These data suggest that carbohydrate source limitations from reduced leaf area development and whole-plant canopy CER lead to decreased fruit fresh and dry weights and delayed ripening in some southern highbush blueberry cultivars.

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Cold Injury of Southern Blueberries as a Function of Germplasm and Season of Flower Bud Development

HortScience ◽

10.21273/hortsci.26.1.18 ◽

1991 ◽

Vol 26 (1) ◽

pp. 18-20 ◽

Cited By ~ 8

Author(s):

Kim Patten ◽

Elizabeth Neuendorff ◽

Gary Nimr ◽

John R. Clark ◽

Gina Fernandez

Keyword(s):

Frost Damage ◽

Vaccinium Corymbosum ◽

Highbush Blueberry ◽

Flower Buds ◽

Flower Bud ◽

Bud Development ◽

Stage Of Development ◽

Cold Damage ◽

Southern Highbush ◽

Flower Bud Development

The relative tolerance of flower buds and flowers of southern highbush blueberry (Vaccinium spp.) to cold damage was compared to rabbiteye (Vaccinium ashei Reade) and highbush blueberry (Vaccinium corymbosum L.). For similar stages of floral bud development, southern highbush and highbush cultivars had less winter freeze and spring frost damage than rabbiteye cultivars. Cold damage increased linearly with stage of flower bud development. Small fruit were more sensitive to frost damage than open flowers. Rabbiteye blueberry flower buds formed during the fall growth flush were more hardy than buds formed during the spring growth flush, regardless of cultivar or stage of development.

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

HortScience ◽

10.21273/hortsci.37.3.539 ◽

2002 ◽

Vol 37 (3) ◽

pp. 539-542 ◽

Cited By ~ 9

Author(s):

Jeffrey G. Williamson ◽

Gerard Krewer ◽

Brian E. Maust ◽

E. Paul Miller

Keyword(s):

Fruit Development ◽

Leaf Development ◽

Fruit Size ◽

Field Trials ◽

Vaccinium Corymbosum ◽

Flower Bud ◽

Hydrogen Cyanamide ◽

South Georgia ◽

Development Period ◽

Southern Highbush

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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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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Reproductive Development in Evergreen vs. Deciduous Blueberry Production System

HortScience ◽

10.21273/hortsci.32.3.443d ◽

1997 ◽

Vol 32 (3) ◽

pp. 443D-443

Author(s):

Peter A.W. Swain ◽

Rebecca L. Darnell

Keyword(s):

Production System ◽

Reproductive Development ◽

Vaccinium Corymbosum ◽

N Fertilization ◽

Highbush Blueberry ◽

Fresh Weight ◽

Flower Buds ◽

Flower Bud ◽

Active Growth ◽

Southern Highbush

Two cultivars of southern highbush blueberry (Vaccinium corymbosum interspecific hybrid) were grown in containers under the traditional deciduous production system, or the dormancy-avoiding evergreen production system. In the dormancy-avoiding system, plants are maintained evergreen and do not enter dormancy in the winter. This alleviates the chilling requirement, thus extending the potential growing area of blueberries into subtropical regions. Plants in the evergreen production system were maintained in active growth through weekly or biweekly N fertilization (≈21–23 g N/ plant per year). Keeping foliage through the year lengthens the duration of the photosynthetic season of the plant and is hypothesized to improve the carbohydrate (CHO) status of the evergreen plants. This, in turn, may decrease source limitations to reproductive development and potentially increase fruit number and/or size. In both cultivars, the evergreen production system advanced the time of anthesis by 3 to 4 weeks compared to the deciduous production system. Plants in the evergreen system initiated 10% to 25% more flower buds than plants in the deciduous system, depending on cultivar. Average leaf area, leaf fresh weight, total above-ground fresh weight, bud density, and cane length were greater in the evergreen plants than deciduous. The evergreen production system increased plant fresh weight and flower bud number compared to the deciduous system, and may ultimately increase yield.

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Carbohydrate Reserve Concentrations and Flower Bud Density Effects on Vegetative and Reproductive Development in Southern Highbush Blueberry

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.125.4.413 ◽

2000 ◽

Vol 125 (4) ◽

pp. 413-419 ◽

Cited By ~ 5

Author(s):

B.E. Maust ◽

J.G. Williamson ◽

R.L. Darnell

Keyword(s):

Leaf Area ◽

Vegetative Growth ◽

Fruit Size ◽

Reproductive Development ◽

Highbush Blueberry ◽

Flower Bud ◽

Vegetative Development ◽

Carbohydrate Reserves ◽

Carbohydrate Reserve ◽

Southern Highbush

Vegetative budbreak, leaf area development, and fruit size in southern highbush blueberry (Vaccinium corymbosum L. interspecific hybrids) decrease as flower bud density increases. The effect on fruit size has been attributed to both insufficient carbohydrate reserves and reductions in current photoassimilates caused by decreased vegetative growth. Experiments were conducted with two southern highbush blueberry cultivars, `Misty' and `Sharpblue', to test the hypothesis that increased carbohydrate reserve concentrations can overcome the detrimental effects of high flower bud density by increasing vegetative budbreak, shoot development, and whole-canopy net CO2 exchange rate (NCER), which in turn will increase fruit size. Fully foliated plants were placed in greenhouses with either ambient (AMB) CO2 levels (≈360 μmol·mol-1) or enriched (ENR) CO2 levels (≈700 μmol·mol-1) for 38 d during fall. Plants were then moved outdoors, hand defoliated, and flower bud density (flower buds/cm cane length) adjusted to range from 0.07 to 0.31. Root starch and whole plant carbohydrate concentrations increased in ENR compared with AMB plants of both cultivars. Vegetative budbreak (number per centimeter cane length), leaf area, and whole-canopy NCER decreased as flower bud density increased in AMB and ENR plants of both cultivars; however, ENR `Sharpblue' plants had significantly greater vegetative growth and wholecanopy NCER at a given flower bud density compared with AMB `Sharpblue'. Concomitant with this was an increase in fruit fresh weight in ENR compared to AMB `Sharpblue'. This was not the case with `Misty', where vegetative development and fruit size were similar in ENR and AMB plants. Thus, the hypothesis that increased carbohydrate reserves will increase vegetative development and subsequent fruit size may be true only in certain cultivars of southern highbush blueberry. Alternatively, the increased carbohydrate reserve concentrations in ENR compared with AMB `Misty' plants may have been insufficient to affect subsequent vegetative or reproductive development.

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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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