shiny black berries persist on the tree through fall and early winter. Highbush blueberry cultivars have been crossed with V. arboreum with the long-range goal of obtaining cultivars with new characteristics ( Lyrene, 2011 ). Vaccinium arboreum can
× velvetleaf blueberry ( Vaccinium myrtilloides ) crosses that resulted in smaller fruit size and later ripening compared with intraspecific lowbush crosses. Similarly, Gupton and Spiers (1994) found that SHB cultivars pollinated with rabbiteye pollen had
2 partial pressure in the range of 8 to 15 kPa is effective in suppressing decay and preserving fresh blueberries stored for several weeks at low temperature. The aim of this study was to investigate the sensitivity of nine blueberry cultivars (Duke
A dichotomous key for the identification of ten commercially important highbush blueberry (Vaccinium corymbosum Ait.) cultivars introduced since 1949 was constructed based on gross morphological characteristics.
Flower bud injury was assessed in 18 cultivars of highbush blueberry (Vaccinium corymbosum L.) after two spring frosts. Bud position on shoots was significantly correlated (P < 0.05) with percent brown ovaries. Significant differences in proportion of brown ovaries were noted among cultivars, but most of the variation was associated with stage of bud development. The least-developed buds were the most hardy. Bloom date was significantly correlated with harvest date across cultivars, although ‘Spartan’ flowered much later than other early ripening cultivars.
Eighty-seven highbush blueberry and species-introgressed blueberry cultivars were evaluated for fruit firmness in the 1998-2000 growing seasons with a FirmTech 1 automated firmness tester. Significant differences were observed among cultivars. An average firmness of 136.1 g·mm-1 of deflection (g·mm-1 dfl) was observed across all studied cultivars, and a range of 80.4 g·mm-1 dfl (`Herbert') to 189.0 g·mm-1 dfl (`Pearl River'). Species ancestry was not consistently related to firmness; however, cultivars with higher firmness values often possessed a higher percentage of Vaccinium darrowi Camp and V. ashei Reade ancestry. Conversely, cultivars with softer than average fruit often possessed a higher percentage of lowbush (V. angustifolium Ait.) ancestry. This information may help to identify sources of breeding material for increased firmness in highbush blueberry hybrids.
The resistance of 26 rabbiteye blueberry (Vaccinium ashei Reade) cultivars to the blighting phase of mummy berry disease was evaluated under controlled conditions. In 1997, blight levels ranged from 31% to 84%, and averaged 61.3% across all cultivars. In 1998, blight levels ranged from 71% to 99%, and averaged 89.9%. Several cultivars, including `Coastal', `Delite', `Centurion', `Walker', `Callaway', and `Garden Blue', exhibited significantly lower levels of mummy berry blight infection in both years. Blighting levels were significantly correlated with new shoot length in 1997, but not in 1998. Rabbiteye blueberry, in general, is less resistant to mummy berry blight than is highbush blueberry (V. corymbosum L.), but several options exist for potential improvement.
Yield component analysis of 9 Vaccinium corymbosum L. blueberry cultivars indicated that yield was more strongly determined by canes per bush and berries per cane than by berry weight. High numbers of berries per cane were associated with low berry weights in all cultivars. Component interactions ranged from slightly additive in ‘Bluecrop’ and ‘Spartan’ to highly compensatory in ‘Rubel’ and ‘Berkeley’. The consideration of component interactions in cultivar trials may enhance the accuracy in identification of desirable genotypes.
Inbreeding coefficients were calculated for the 63 cultivars of blueberry (Vaccinium corymbosum L.) released by public agencies in the United States. A steady increase in coefficients was noted from the period of 1910−1920 (F=0.00) to 1960−1970 (F=0.13). ‘Lateblue’ and ‘Flordablue’ had the highest coefficient of 0.25. Most of the genes in the cultivars came from the wild selections ‘Brooks’, ‘Sooy’ and ‘Rubel’.
Mechanical pollination trials using air blasts and vibration to distribute pollen were conducted on the highbush blueberry, Vaccinium corymbosum cvs. ‘Jersey’ and ‘Rubel’. Neither treatment nor a simultaneous combination of the two gave commercial fruit set for either cultivar. Mechanical trials on the ‘Rubel’ cultivar indicated almost total failure to effect pollination. Production from ‘Jersey’ cultivar mechanical pollination trials was more promising. However, low seed numbers indicated that the increased production of this cultivar might be due to its tendency to set fruit parthenocarpically.