Calcium and Fruit Firmness in Highbush Blueberry: Natural Gradients and the Effect of Foliar Applications

Calcium gradients were established in firm (`Bluecrop' and `Blueray') and soft (`Ivanhoe') highbush blueberry (Vaccinium corymbosum L.) fruits from a 7-year-old planting at La Union, southern Chile. Manual firmness measurements established that `Ivanhoe' fruit was softer than either `Bluecrop' or `Blueray'. In all varieties, Ca concentrations were: seed > pulp > epidermis; opposite trends were found for K+Mg/Ca ratios. Seed number and Ca concentration in the pulp were negatively correlated in `Bluecrop' and `Ivanhoe', but not in `Blueray'. In a related experiment, the response of `Bluecrop' to preharvest sprays of two calcium sources (chloride and nitrate) in four doses (0, 47.5, 35, or 190 g Ca/100 liters of water) was studied; dose and source interactions were not significant. Both calcium sources affected fruit Ca concentrations similarly;l calcium applications, either as nitrate or chloride, increased Ca significantly in epidermis and seed; the highest dose was required to raise significantly Ca concentrations in the pulp. K+Mg/Ca ratios in nitrate- or chloride-treated fruit were: pulp > seed > epidermis.

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Pollination Requirements of Three Highbush Blueberry (Vaccinium corymbosum L.) Cultivars

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.122.6.891 ◽

1997 ◽

Vol 122 (6) ◽

pp. 891-896 ◽

Cited By ~ 25

Author(s):

Kenna E. MacKenzie

Keyword(s):

Seed Coat ◽

Fruit Set ◽

Vaccinium Corymbosum ◽

Harvest Date ◽

Highbush Blueberry ◽

Seed Number ◽

Berry Size ◽

Low Levels ◽

Viable Seeds ◽

Total Seed

The effects of pollination treatments on fruit set and five berry characteristics [mass, diameter, number of apparently viable seeds (well-developed, plump with dark seed coat), total seed number (includes apparently viable and partially developed seeds), and harvest date] were examined on three highbush blueberry cultivars. Pollination treatments included unpollinated, open pollinated, emasculated, and three hand pollinations that used pollen from the same flower, from the same cultivar, or from a different cultivar. Berries matured earliest and were smallest with the most apparently viable seeds in `Northland', `Patriot' had the greatest fruit set and smallest seed number, and `Bluecrop' matured the latest. Fruit set was greater, berry size larger, seed number smaller, and maturation later in 1990 than 1991. For all three cultivars, berries were generally smallest, latest maturing, and had the fewest seeds when pollination was prevented and were largest with the most seeds and earliest maturing in open visitation. Emasculation resulted in berries similar to those from unpollinated flowers. For berry characteristics, cross-pollination was of benefit for `Patriot' and possibly `Northland' but not `Bluecrop'. Thus, commercial highbush blueberry planting designs must be based on the pollination requirements of the particular cultivar. `Northland' berries almost always had seeds, while `Patriot' showed high levels and `Bluecrop' low levels of parthenocarpy.

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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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Use of Combinations of Commercially Relevant O2 and CO2 Partial Pressures to Evaluate the Sensitivity of Nine Highbush Blueberry Fruit Cultivars to Controlled Atmospheres

HortScience ◽

10.21273/hortsci.46.1.74 ◽

2011 ◽

Vol 46 (1) ◽

pp. 74-79 ◽

Cited By ~ 14

Author(s):

Nihad Alsmairat ◽

Carolina Contreras ◽

James Hancock ◽

Pete Callow ◽

Randolph Beaudry

Keyword(s):

Maximum Level ◽

Vaccinium Corymbosum ◽

Highbush Blueberry ◽

Dependent Manner ◽

Fruit Firmness ◽

Atmospheric Conditions ◽

Negative Effects ◽

Controlled Atmospheres ◽

Partial Pressures ◽

The Impact

We tested the impact of storage atmospheres in which the CO2 and O2 percentages sum to 21% on highbush blueberry (Vaccinium corymbosum L.) fruit condition and quality. The CO2 and O2 combinations, in percent composition, were 19%/2%, 18%/3%, 16.5%/4.5%, 15%/6%, 13.5%/7.5%, 12%/9%, 6%/15%, and 0%/21% for CO2/O2, respectively. Nine blueberry cultivars were evaluated (Duke, Toro, Brigitta, Ozarkblue, Nelson, Liberty, Elliott, Legacy, and Jersey) after 8 weeks of controlled atmosphere (CA) storage at 0 °C. Surface mold, berry decay, skin reddening (associated with fruit pulp browning), fruit firmness, pulp discoloration, and the content of ethanol and acetaldehyde were assessed. Fruit firmness, skin reddening, and decay declined and the proportion of fruit with severe internal discoloration tended to increase as CO2 concentrations increased. Ethanol and acetaldehyde accumulation was minimal, indicating fermentation was not induced by the atmospheric conditions applied. Cultivar effects were far more pronounced than atmosphere effects. Some cultivars such as Duke, Toro, Brigitta, Liberty, and Legacy appear to be well suited to extended CA storage, whereas other cultivars such as Elliott stored moderately well, and Ozarkblue, Nelson, and Jersey stored poorly. The data indicate that responses to high levels of CO2, while O2 is maintained at its maximum level practicable, can, in a cultivar-dependent manner, include significant negative effects on quality while achieving the desired suppression of decay.

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Increasing Honey Bee Hive Densities Promotes Pollination and Yield Components of Highbush Blueberry in Western Washington

HortScience ◽

10.21273/hortsci12644-17 ◽

2018 ◽

Vol 53 (2) ◽

pp. 191-194

Author(s):

Matthew Arrington ◽

Lisa Wasko DeVetter

Keyword(s):

Honey Bee ◽

Honey Bees ◽

Yield Components ◽

Fruit Set ◽

Vaccinium Corymbosum ◽

Highbush Blueberry ◽

Seed Number ◽

Berry Weight ◽

Berry Size ◽

Western Washington

Yield components including fruit set and berry size in northern highbush blueberry (Vaccinium corymbosum) can be limited in key production regions like western Washington. Climactic conditions influence the activity levels of blueberry’s primary commercial pollinator, honey bee (Apis mellifera). Cool springs with frequent rainfall, which are common during the spring bloom period in western Washington, can reduce honey bee activity, pollination efficiency, and subsequent fruit set and yields. Increasing honey bee hive density may be a simple technique that growers can employ to increase the number of honey bees foraging during periods of good weather, interspersed with the poor weather, and therefore, increase fruit set and related yield components. The objective of this study was to evaluate if increased honey bee hive densities improve pollination and subsequent yield components in western Washington blueberry. Three field sites with mature ‘Duke’ plants were stocked with 10 hives/ha of honey bees (control), and three other field sites (also ‘Duke’) were stocked with 20 hives/ha (high hive density). Honey bee visitation and yield components, including fruit set and berry weight, were measured. Estimated yield, seed number/berry, and fruit firmness were also monitored. There were no significant differences in fruit set regardless of honey bee hive density. However, honey bee visitation and estimated yield increased with increased honey bee hive density. Berry weight and seed number per berry were also increased with increased honey bee hive density, although firmness was unaffected. Results indicate that increasing honey bee hive densities can help blueberry growers improve berry size and overall yields, suggesting this is a practice growers can implement if their production is constrained by insufficient pollination.

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