Preharvest long-term exposure to UV-B radiation promotes fruit ripening and modifies stage-specific anthocyanin metabolism in highbush blueberry

AbstractUltraviolet-B (UV-B) light (280–315 nm) is an important environmental signal that regulates plant development and photomorphogenesis, while also affecting the flavonoid pathway, including anthocyanin biosynthesis. Regarding the effects of UV-B radiation on fruits, the effects of a short-term or postharvest irradiation on fruit quality have been well-documented, but the effects of a long-term preharvest UV-B irradiation on fruit growth and coloration remain unclear. Thus, in this study, we investigated the effects of a long-term treatment involving an environmentally relevant UV-B dose on highbush blueberry (Vaccinium corymbosum) fruit. The preharvest UV-B treatment quickly promoted fruit growth and sugar accumulation, which is not commonly observed in other fruit tree species. The UV-B exposure also accelerated fruit ripening and coloration. The dual-luciferase assay proved that in blueberries, expression of VcUFGT encoding anthocyanin biosynthesis key enzyme, is positively and negatively regulated by VcMYBA1 and VcMYBC2, respectively. Throughout the fruit development stage, the UV-B treatment up-regulated VcMYBPA1 expression, which increased VcUFGT expression via VcMYBA1. In the green fruit stage, the UV-B treatment increased HY5 encoding UV receptor, which up-regulates VcMYBPA1 and down-regulates VcMYBC2, thereby promotes the accumulation of anthocyanins. On the other hand, excessive anthocyanin synthesis was inhibited by increased VcMYBC2 levels in mature fruits when exposed to UV-B light through HY5-independent pathway. In conclusion, anthocyanin-related MYB activators and repressor may coordinately balance the accumulation of anthocyanins in blueberry fruits, with UV-B treatments possibly influencing their effects in a stage-specific manner. The potential utility of preharvest UV-B treatments for improving blueberry fruit quality is discussed herein.

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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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Effects of Machine-Harvest Interval on Fruit Quality of Fresh Market Northern Highbush Blueberry

Horticulturae ◽

10.3390/horticulturae7080245 ◽

2021 ◽

Vol 7 (8) ◽

pp. 245

Author(s):

Yixin Cai ◽

Fumiomi Takeda ◽

Brian Foote ◽

Lisa Wasko DeVetter

Keyword(s):

Fruit Quality ◽

Titratable Acidity ◽

Vaccinium Corymbosum ◽

Soluble Solids ◽

Highbush Blueberry ◽

Labor Costs ◽

Fresh Market ◽

Harvest Intervals ◽

Northern Highbush Blueberry

Machine harvesting blueberry (Vaccinium sp.) alleviates labor costs and shortages but can reduce fruit quality. Installation of softer catching surfaces inside modified over-the-row harvesters (modified OTR) and adjusting harvest intervals may improve fruit quality and packout. The objective of this study was to determine the effect of harvest interval on fruit quality of fresh market northern highbush blueberry (Vaccinium corymbosum L.) harvested using a modified OTR. ‘Liberty’ blueberry bushes were harvested by hand or using a modified OTR at 3-, 10-, and 14-day intervals in 2019 and at 7-, 11-, and 14-day intervals in 2020. Hand-harvested ‘Liberty’ had greater packout and firmness than machine-harvested fruit. Machine harvesting at the 3-day interval in 2019, and the 14-day interval in 2020 reduced packout from 70–80% to 60% and 54%, respectively. In 2019, machine harvesting at a 3-day interval overall resulted in fruit with greater firmness, higher titratable acidity (TA), and lower total soluble solids (TSS) and SS/TA, compared to other harvest intervals. In 2020, the 7-day machine-harvest interval had a greater TA and lower TSS/TA, compared to the 11- and 14-day intervals. Overall, modified OTR machine-harvest intervals can be extended to 10–11 days for fresh market northern highbush cultivars such as ‘Liberty’ grown in northwest Washington.

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Comparing the Efficacy of Postharvest Cooling Methods to Enhance Fruit Quality and Reduce Salmonella in Artificially Inoculated Southern Highbush Blueberry

HortTechnology ◽

10.21273/horttech04238-19 ◽

2019 ◽

Vol 29 (3) ◽

pp. 314-319 ◽

Cited By ~ 1

Author(s):

Jaysankar De ◽

Aswathy Sreedharan ◽

You Li ◽

Alan Gutierrez ◽

Jeffrey K. Brecht ◽

...

Keyword(s):

Shelf Life ◽

Fruit Quality ◽

Microbiological Quality ◽

Vaccinium Corymbosum ◽

Temperature Management ◽

Air Cooling ◽

Highbush Blueberry ◽

Fresh Market ◽

Southern Highbush

Cooling procedures used by blueberry (Vaccinium sp.) growers often may include delays up to 24 hours that can damage the fruit through rough handling and adverse temperatures, thereby potentially compromising quality and, subsequently, safety. The objectives of this experiment were to compare forced-air cooling (FAC) compared to hydrocooling without sanitizer (HW) and hydrocooling with sanitizer (HS) regarding the quality and shelf life of southern highbush blueberry [SHB (Vaccinium corymbosum)] and to determine the efficacy of these treatments for reducing Salmonella in SHB. Freshly harvested SHB that were inoculated with a five-serovar cocktail of rifampin-resistant Salmonella were rapidly chilled by FAC or hydrocooling (HW and HS) using a laboratory model system. FAC did not show any significant reduction (P > 0.05) in Salmonella or in the effects on the microbiological quality of blueberries. HW and HS reduced Salmonella by ≈2 and >4 log cfu/g SHB, respectively, on day 0. These postharvest treatments were also evaluated for their ability to help maintain fruit quality throughout a storage period of 21 days at 1 °C. Hydrocooling (both HS and HW) provided more rapid cooling than FAC. Hydrocooled blueberries showed significant weight gain (P < 0.05), whereas FAC resulted in a slight, but insignificant (P > 0.05), reduction in final weight. The results of hydrocooling, both HS and HW, shown in this study could help to extend the shelf life while maintaining or increasing the microbiological quality of fresh market blueberries. Information obtained by this study can be used for developing the best temperature management practices to maintain the postharvest safety and quality of blueberries.

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Optimizing Nitrogen Fertigation Rates for Young Southern Highbush Blueberry

Agronomy ◽

10.3390/agronomy10030389 ◽

2020 ◽

Vol 10 (3) ◽

pp. 389

Author(s):

Yang Fang ◽

Jeffrey Williamson ◽

Rebecca Darnell ◽

Yuncong Li ◽

Guodong Liu

Keyword(s):

Fruit Quality ◽

Ground Cover ◽

Vaccinium Corymbosum ◽

Fruit Yield ◽

Growth And Yield ◽

Nutrient Concentrations ◽

Highbush Blueberry ◽

Soil Nitrate ◽

Southern Highbush ◽

N Rates

The commercial blueberry industry in Florida has expanded significantly in both acreage and value in the past several years. The southern highbush blueberry (SHB, Vaccinium corymbosum L. interspecific hybrid) is the major blueberry type grown in Florida. The nitrogen (N) demand of young SHB differs from the northern highbush blueberry (NHB, V. corymbosum L.) and from mature blueberry plants. The objective of this study was to optimize fertigated N rates for the growth and yield of young SHB plants. One-year-old ‘Emerald’ and ‘Farthing’ plants were fertilized with 32N-0P-0K through drip irrigation at annual rates of 0, 42, 84, 168, and 336 kg N ha−1. Soil nitrate levels at multiple depths were measured along with leaf nutrient concentration, percent canopy ground cover, fruit yield and fruit quality. The results indicated that N rates had no significant effect on leaf nutrient concentrations. Greater N rates advanced bloom and harvest, increased percentage of ground cover (an indicator of canopy size), fruit yield and berry numbers per plant, but decreased mean berry diameter and weight. The soil nitrate results from both ‘Emerald’ and ‘Farthing’ revealed that the 336 kg N ha−1 treatment had a significantly greater risk for nitrate leaching than the lower N treatments in spring. The effect of N rates on fruit quality varied with cultivar and harvest season. The linear plateau regression of fruit yield and N rates indicated that the maximum yield reached at the annual N fertigation rate of 222 kg ha−1 for ‘Emerald’ and 206 kg ha−1 for ‘Farthing’.

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Nectarine Fruit Ripening and Quality Assessed Using the Index of Absorbance Difference (IAD)

International Journal of Agronomy ◽

10.1155/2013/242461 ◽

2013 ◽

Vol 2013 ◽

pp. 1-9 ◽

Cited By ~ 14

Author(s):

E. Bonora ◽

D. Stefanelli ◽

G. Costa

Keyword(s):

Fruit Quality ◽

Fruit Ripening ◽

Solid Content ◽

Training System ◽

Fruit Growth ◽

Soluble Solid Content ◽

Training Systems ◽

Climacteric Fruit ◽

Soluble Solid ◽

Absorbance Difference

Consistency of fruit quality is extremely important in horticulture. Fruit growth and quality in nectarine are affected by fruit position in the canopy, related to the tree shape. The “open shaped” training systems, such as Tatura Trellis, improve fruit growth and quality. The Index of Absorbance Difference (IAD) is a new marker that characterizes climacteric fruit during ripening. A study on fruit ripening was performed by using theIADon nectarine to monitor fruit maturity stages of two cultivars trained as Tatura Trellis in Victoria, Australia. Fruit of cv “Summer Flare 34” (“SF34”) grown in different positions on the tree showed high ripening homogeneity. Fruit harvested at a similar ripening stage showed fruit firmness and soluble solid content homogeneity. Fruits from hand-thinned variety “Summer Flare 26” (“SF26”) were larger in size, had advanced ripening, and showed greater homogeneity. For “SF26”, a weak correlation betweenIADand SSC was observed. The experiment showed that the Tatura Trellis training system is characterized by high homogeneity of nectarine fruit when coupled with a proper management of fruit density. It also confirmed that theIADcould be used as new nondestructive maturity index for nectarine fruit quality assessment in the field.

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Analysis of highbush blueberry (Vaccinium corymbosum L.) fruit growth with exponential mixed models

Scientia Horticulturae ◽

10.1016/j.scienta.2007.10.018 ◽

2008 ◽

Vol 115 (4) ◽

pp. 368-376 ◽

Cited By ~ 18

Author(s):

Carlos Godoy ◽

Gloria Monterubbianesi ◽

Jorge Tognetti

Keyword(s):

Mixed Models ◽

Vaccinium Corymbosum ◽

Fruit Growth ◽

Highbush Blueberry

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Potential of Deficit Irrigation, Irrigation Cutoffs, and Crop Thinning to Maintain Yield and Fruit Quality with Less Water in Northern Highbush Blueberry

HortScience ◽

10.21273/hortsci11533-16 ◽

2017 ◽

Vol 52 (4) ◽

pp. 625-633 ◽

Cited By ~ 3

Author(s):

Khalid F. Almutairi ◽

David R. Bryla ◽

Bernadine C. Strik

Keyword(s):

Water Use ◽

Fruit Quality ◽

Deficit Irrigation ◽

Vaccinium Corymbosum ◽

Soluble Solids ◽

Highbush Blueberry ◽

Stem Water Potential ◽

Full Irrigation ◽

Northern Highbush Blueberry ◽

Stem Water

Drought and mandatory water restrictions are limiting the availability of irrigation water in many important blueberry growing regions, such as Oregon, Washington, and California. New strategies are needed to maintain yield and fruit quality with less water. To address the issue, three potential options for reducing water use, including deficit irrigation, irrigation cutoffs, and crop thinning, were evaluated for 2 years in a mature planting of northern highbush blueberry (Vaccinium corymbosum L. ‘Elliott’). Treatments consisted of no thinning and 50% crop removal in combination with either full irrigation at 100% of estimated crop evapotranspiration (ETc), deficit irrigation at 50% ETc (applied for the entire growing season), or full irrigation with irrigation cutoff for 4–6 weeks during early (early- to late-green fruit) or late (fruit coloring to harvest) stages of fruit development. Stem water potential was similar with full and deficit irrigation but, regardless of crop thinning, declined by 0.5–0.6 MPa when irrigation was cutoff early and by >2.0 MPa when irrigation was cutoff late. In one or both years, the fruiting season was advanced with either deficit irrigation or late cutoff, whereas cutting off irrigation early delayed the season. Yield was unaffected by deficit irrigation in plants with a full crop load but was reduced by an average of 35% when irrigation was cutoff late each year. Cutting off irrigation early likewise reduced yield, but only in the 2nd year when the plants were not thinned; however, early cutoff also reduced fruit soluble solids and berry weight by 7% to 24% compared with full irrigation. Cutting off irrigation late produced the smallest and firmest fruit with the highest soluble solids and total acidity among the treatments, as well as the slowest rate of fruit loss in cold storage. Deficit irrigation had the least effect on fruit quality and, based on these results, appears to be the most viable option for maintaining yield with less water in northern highbush blueberry. Relative to full irrigation, the practice reduced water use by 2.5 ML·ha−1 per season.

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New Foliar-applied Biofilm Had No Impact on Splitting or Fruit Quality in ‘Elliott’ and ‘Legacy’ Blueberry in Oregon

HortTechnology ◽

10.21273/horttech04196-18 ◽

2018 ◽

Vol 28 (6) ◽

pp. 836-842

Author(s):

Amanda J. Vance ◽

Bernadine C. Strik

Keyword(s):

Fruit Quality ◽

Color Change ◽

Vaccinium Corymbosum ◽

Sprinkler System ◽

Soluble Solids ◽

Highbush Blueberry ◽

Fresh Market ◽

Visual Rating ◽

Berry Size ◽

Current Product

Fresh market blueberry (Vaccinium sp.) sales require high-quality, firm fruit with no significant defects. A new phospholipid biofilm product was developed to reduce splitting and increase firmness when applied directly to blueberry fruit. Two trials were undertaken to test the effects of the biofilm using various application timings and methods. In highbush blueberry cultivar Elliott (Vaccinium corymbosum), four treatments included: 1) rate and timing on the current product label (5- to 10-mm berry size, 10% to 20% color change, and between the first and second harvests), 2) addition of a preharvest timing (5- to 10-mm berry size, 10% to 20% color change, and 7 to 10 days preharvest); 3) starting applications later (10% to 20% color change, 7 to 10 days preharvest, and between the first and second harvests), and 4) a water-sprayed control. Biofilm was applied at a rate of 2 qt/acre for all applications. In highbush blueberry cultivar Legacy (Vaccinium corymbosum × Vaccinium sp.), the same volume of biofilm was applied via an airblast sprayer or through an overhead sprinkler system typically used for chemigation and compared with a water-sprayed control. Data collected included yield (in ‘Elliott’), berry weight, firmness, skin toughness, total soluble solids (TSS), weight loss during storage, percent splitting (in ‘Legacy’), and a visual rating, evaluated on the day of harvest and about 14 and 28 days postharvest. There were no visual defects caused by application of biofilm. Compared with the controls in either study, biofilm had no consistent impact on fruit quality, firmness, shelf life, yield in ‘Elliott’, or splitting in ‘Legacy’.

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