scholarly journals Flowering and fruit set of six cultivars of highbush blueberry (Vaccinium corymbosum L.) in the conditions of the Lublin Region

2012 ◽  
Vol 62 (1) ◽  
pp. 91-96 ◽  
Author(s):  
Małgorzata Bożek

The results presented in this paper relate to the time and duration of flowering of highbush blueberry as well as fruit set in the conditions of flower isolation and free visitation by pollinating insects. Observations were carried out in the years 2001- 2004 at a plantation located in Niemce near the city of Lublin. Six cultivars: 'Bluecrop', 'Bluejay', 'Croatan', 'Darrow', 'Northland' and 'Spartan', were covered by the study. The flowering period of the studied highbush blueberry cultivars was in May in three years of study, whereas in 2004 in May and June. Depending on the year, it lasted from 14 up to 21 days, on the average. Significant differences were found in the life span of a single flower which, depending on the cultivar and conditions prevailing during flowering, bloomed from 5 up to 10 days (the average for all the years for all the cultivars). With free access of pollinating insects, highbush blueberry set an average of 92 false-berries per 100 flowers, whereas only 40 during spontaneous self-pollination under the isolating cover. In each year of study, irrespective of atmospheric conditions prevailing during flowering as well as the time and duration of flowering, fruit set of the investigated cultivars in flowers freely accessible to pollinating insects should be considered to be good or very good.

1997 ◽  
Vol 66 (2) ◽  
pp. 267-272 ◽  
Author(s):  
Akira Suzuki ◽  
Toru Kikuchi ◽  
Koji Aoba

1997 ◽  
Vol 122 (6) ◽  
pp. 891-896 ◽  
Author(s):  
Kenna E. MacKenzie

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.


2014 ◽  
Vol 67 (3) ◽  
pp. 13-20 ◽  
Author(s):  
Ernest Stawiarz ◽  
Anna Wróblewska

<p class="abstracttekst">Under the conditions of Lublin (central-eastern Poland), observations were conducted on the flowering of <em>Caragana arborescens </em>shrubs for two growth seasons as well as nectar and pollen production by the flowers of this species was investigated.</p><p class="abstracttekst">The flowering period of <em>Caragana arborescens </em>began at the turn of April and May and lasted for 24 days, while for a single flower it was 6.30 ± 0.79 days. The average weight of nectar, sugars and pollen produced by 10 Siberian peashrub flowers was, respectively: 46.70 ± 8.39 mg, 22.79 ± 6.10 mg, and 4.45 ± 0.34 mg. The nectar sugar concentration amounted 49.60 ± 10.08%. Pollen grains reached average dimensions of 21.94 ± 0.76 µm x 21.52 ± 0.71 µm. During a growing season, one <em>Caragana arborescens</em> shrub can provide on average 101.8 g of nectar, 49.7 g of sugars, and 9.7 g of pollen.</p>


HortScience ◽  
2001 ◽  
Vol 36 (1) ◽  
pp. 133-135 ◽  
Author(s):  
Mark K. Ehlenfeldt

Self- and cross-fertility were evaluated in the highbush blueberry (Vaccinium corymbosum L.) cultivars Bluegold, Duke, Legacy, Nelson, Sierra, Sunrise, and Toro, all of which have been released since 1985, by comparing them with `Bluecrop' and `Rubel', which were used as standards. Cross-pollination increased fruit set in all cultivars except `Bluecrop', in which set was reduced 13%. The average increase among recently released cultivars was 43%. Cross-pollination also increased fruit weight for all cultivars except `Rubel'. Average increase in fruit weight with cross-pollination of the recently released cultivars was 27%. Fruit set and fruit weight measurements suggest that `Duke', `Legacy', and `Nelson' would perform satisfactorily in solid stands, and that `Sierra' and `Toro' probably need cross-pollination for maximum yields.


HortScience ◽  
2007 ◽  
Vol 42 (7) ◽  
pp. 1612-1615 ◽  
Author(s):  
Jeffrey G. Williamson ◽  
D. Scott NeSmith

Greenhouse and field experiments were conducted to determine the effects of the growth regulator N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU) on fruit set, berry size, and yield of southern highbush blueberry (Vaccinium corymbosum hybrids). The experiments were conducted over a period of several years in Georgia and Florida. CPPU sprays were capable of increasing fruit set and berry weight of southern highbush blueberry, although the responses to CPPU treatment were variable and appeared to be influenced by factors such as rate, spray timing, and cultivar. In Florida, high natural fruit set may have prevented increased fruit set from CPPU. A slight delay in berry maturity was noted in several experiments. Spray burn occurred on several occasions and may be related to factors such as cultivar, rate, spray volume, and use of surfactant.


2016 ◽  
Vol 26 (2) ◽  
pp. 213-219 ◽  
Author(s):  
Sarah K. Taber ◽  
James W. Olmstead

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.


HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 793A-793
Author(s):  
Jeffrey G. Williamson* ◽  
E. Paul Miller

Poor fruit set and sub-optimum berry size are potential yield- and profit-limiting factors for southern highbush (Vaccinium corymbosum) blueberry production in Florida. The cytokinin N-(2-chloro-4-pyridyl)-N'-phenylurea (CPPU) has increased fruit size and fruit set of a number of fruit crops including rabbiteye blueberry. The purpose of this study was to determine the effects of CPPU applied at different rates and phenological stages of bloom and/or fruit development on fruit size, set, and yield of southern highbush blueberry. `Millennia' and `Star' southern highbush blueberry plants located on a commercial blueberry farm in Alachua County, Fla., were treated with 5 or 10 ppm CPPU at various stages of development ranging from full bloom to 20 days after full bloom. In contrast to findings with rabbiteye blueberry, fruit set in this study of southern highbush blueberry was not affected by any of the CPPU treatments when compared to the controls. Nor was total fruit yield affected by CPPU treatments. The most noticeable potential benefit found in this study was an increase in mean fruit fresh weight from CPPU treatments. However, cultivars responded differently to CPPU with respect to mean fruit fresh weight. For `Millennia', only one CPPU treatment increased mean fruit weight compared to controls. However, for `Star', all but one CPPU treatment increased mean fruit fresh weight. Several CPPU treatments resulted in delayed fruit ripening for `Star' but not for `Millennia'. For `Star', the treatments that most consistently delayed fruit ripening tended to have greater fruit fresh weights.


HortScience ◽  
2011 ◽  
Vol 46 (1) ◽  
pp. 74-79 ◽  
Author(s):  
Nihad Alsmairat ◽  
Carolina Contreras ◽  
James Hancock ◽  
Pete Callow ◽  
Randolph Beaudry

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.


HortScience ◽  
2017 ◽  
Vol 52 (9) ◽  
pp. 1259-1264 ◽  
Author(s):  
Matthew Arrington ◽  
Lisa Wasko DeVetter

Fruit set in northern highbush blueberry (Vaccinium corymbosum L.) can be low under certain climatic conditions, contributing to reduced yields in northwestern Washington. The mechanisms influencing fruit set are complex, but reduced fruit set may be associated with inadequate nutrient availability during critical stages of flowering, ovule fertilization, and initial fruit development. Calcium (Ca) and boron (B) are of particular interest for reproductive developmental processes and are frequently applied annually by growers in the Pacific Northwest region because of the perception that these nutrients enhance fruit set and corresponding yields. Evaluation of commonly applied products containing these nutrients and their effects on fruit set and yield are of specific importance to justify the application of these nutrients. To address this, commercially available fertilizers containing Ca and B were applied to ‘Draper’ and ‘Bluecrop’ blueberry as foliar sprays, either alone or in combination, during the 2015 and 2016 growing seasons in northwestern Washington. Treatments included calcium chloride (750 and 1500 ppm Ca), calcium sulfate (150 ppm Ca), and tetra borate (125 and 250 ppm B) foliar sprays, repeated six times per season every 7–10 days from early pink bud through petal fall. No significant increases were observed for fruit set, estimated yield, and fruit quality (firmness and berry weight) across the treatments. Increased concentrations of B were observed in leaf tissues in 2015 and 2016, and to a lesser extent fruit tissues. Calcium remained unchanged regardless of treatment and tissue type. Under the conditions of this study, foliar applications of Ca and B did not lead to increased fruit set or yield. This research suggests that other approaches should be explored to increase fruit set and corresponding yields of highbush blueberry grown in northwest Washington.


HortScience ◽  
2017 ◽  
Vol 52 (6) ◽  
pp. 844-851 ◽  
Author(s):  
Bernadine C. Strik ◽  
Amanda J. Vance ◽  
Chad E. Finn

Northern highbush blueberry (Vaccinium corymbosum L.) cultivars were evaluated from planting (Oct. 2006) through 2014 in a certified organic research site in Aurora, OR. The treatments included cultivar (Duke, Bluecrop, Reka, Bluejay, Bluegold, Draper, Legacy, Liberty, Ozarkblue, and Aurora), amendment-mulch [“compost + sawdust” (included preplant amendment and a surface mulch of either an agricultural on-farm crop waste compost or yard-debris compost and sawdust), and “weed mat” (no preplant amendments but with a sawdust mulch topped with weed mat)]. Adding on-farm compost as a preplant amendment and as part of the mulching program increased soil pH from 4.9 to 6.9, organic matter content (OM), and calcium (Ca), magnesium (Mg), and potassium (K) levels compared with the weed mat treatment. The reduced plant growth and yield in some cultivars grown in the compost + sawdust treatment was likely due to the higher soil pH. ‘Bluegold’ and ‘Draper’ were among the cultivars with consistently high flower bud set (40% to 57%), whereas others had consistently low values (e.g., 22% to 45% in ‘Bluecrop’). The number of flowers per bud was affected only by cultivar. There was no effect of year or amendment-mulch treatment on percent fruit set which averaged 93% during the study; however, ‘Ozarkblue’ had a significantly lower fruit set (88%) than only ‘Aurora’ (96%). Berry weight was affected by year (plant age), cultivar, and amendment-mulch treatment. ‘Ozarkblue’ produced the largest berries. Type of amendment-mulch had little effect on berry weight, except in ‘Ozarkblue’, ‘Aurora’, and ‘Reka’ where plants grown with weed mat produced larger fruit than those grown with compost + sawdust. On average, ‘Bluejay’, ‘Draper’, and ‘Liberty’ fruit had the highest percent soluble solids (TSS) and ‘Ozarkblue’ the lowest. Fruit harvested from plants grown with weed mat were firmer than when compost + sawdust was used. ‘Draper’ fruit were much firmer than those of the other cultivars in all years of the study. The number of flower buds per plant multiplied by the number of flowers/bud and berry weight (cultivar specific) and average fruit set was a good predictor of yield in young plants. Yield per plant increased from the second through seventh growing seasons as plants matured in all cultivars except for ‘Duke’ which had the greatest yield in 2014. Cumulative yield was highest in ‘Legacy’ and lowest in ‘Bluejay’ and in ‘Draper’, which had relatively low yield when plants were young. Most cultivars had greater yield when grown with weed mat, whereas ‘Bluegold’ and ‘Liberty’ were unaffected by amendment-mulch treatment. Because weeds were managed in all plots, the cultivar response to amendment-mulch was likely a reflection of sensitivity to preplant amendment with on-farm compost and the resulting higher soil pH. It is possible that the cultivars differed in their adaptability to the various fertility regimes caused by the amendment-mulch treatments and fertilizers used in our study.


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