Ⅰ. Growth and Fruit Characteristics of Highbush Blueberry Cultivars
In 2008, cultivar characteristics (growth and fruit quality) were investigated from 20 highbush blueberry cultivars at Jeollabuk-Do Agricultural Research and Extension Services. For...
Ⅰ. Growth and Fruit Characteristics of Highbush Blueberry Cultivars
In 2008, cultivar characteristics (growth and fruit quality) were investigated from 20 highbush blueberry cultivars at Jeollabuk-Do Agricultural Research and Extension Services. For this study, two-year old seedlings had been transplanted in 2006. The results showed that bloom period was the earliest in ‘Collins’ (16 April) and latest in ‘Darrow’ and ‘Elliott’ (29 April). Fruit set were higher in ‘Bluecrop’, ‘Collins’, ‘Duke’, ‘Jersey’, ‘Northland’, ‘Rancocas’, and ‘Sierra’ than ‘Berkley’, ‘Blueray’, ‘Chandler’, ‘Elliot’, ‘Nelson’, and ‘Spartan’. Fruit was larger in ‘Berkley’, ‘Chandler’, ‘Patriot’, and ‘Spartan’(>3.5 g), than ‘Collins’, ‘Jersey’, ‘Northblue’, ‘Northland’, and ‘Rancocas’(<2.4 g). The varieties showing relatively high TSS (>13°Brix) were ‘Bluejay’, ‘Blueray’, ‘Coville’, ‘Darrow’, ‘Dixi’, ‘Jersey’, and ‘Northland’. Anthocyanin content was in the range of 55~155 mg/100 g and the cultivars with more than 100 mg/100 g were ‘Bluejay’, ‘Collins’, ‘Coville’, ‘Elliott’, ‘Jersey’, ‘Northblue’, ‘Patriot’, and ‘Rancocas’ varieties. Principal component analysis using 21 characteristics of highbush blueberry, the 20 cultivars were classified into five group by maturing time and yield.
Ⅱ. Establishment of the Propagation Methods by Cuttings for Blueberry Plants
This study was carried out to determine the optimal conditions for the propagation by cuttings of highbush blueberry plants. The pH of the media for cuttings was 4.3 for peatmoss only, 4.4~4.6 for peatmoss +sand, and 4.6~4.7 for peatmoss+perlite. The most optimal medium for rooting was peatmoss:perlite(7:3) in which rooting, root length and root weight were good. Mean percent budding of the cuttings was promoted when PGRs were applied. Determined 90 days after cutting, callus development and rooting rate were high with 500 mg·L-1 NAA for the cultivars ‘Bluecrop’ and ‘Sunrise’ cultivars but IBA at 500 mg·L-1 promoted rooting in ‘Duke’. Mean temperatures of the media for cuttings decreased with increasing level of shading; compared to non-shading control, shading reduced temperatures by 1.1~2.2℃ around 9 AM, by 3.3~4.8℃ around 1 PM, and by 2.6~3.6℃ 5 PM. Callus development and rooting rate were highest with 30% shading. The rooting rate from the hardwood cutting varied according to the time of sampling; rooting rate was higher in the cuttings sampled in early April, compared to the mid March samples. The growth potential of roots and shoots of the cuttings increased with increasing number of nodes per cutting. Considering rooting rate and cutting efficiency, 4~5 nodes per cutting was considered to be optimal.
Ⅲ. Soil Management of Blueberry
The main objective of this study was to develop the soil management techniques for improving blueberry production, which included the investigation of the effects of mounding height, incorporated organic materials, and mulching materials. Several organic materials were tested for their alternative to peatmoss, when partly composted pine needles, rice hulls and sawdust were used alone or in mixture. The pH of the organic materials was the lowest in peatmoss (4.3), followed by pine needles (4.8), sawdust (5.7) and rice hulls (7.8). Soil water content was maintained highest in peatmoss + pine needles, followed by peat only, peatmoss + sawdust and peatmoss + rice hulls. Soil pH that measured after incorporation of organic materials into the soil was similar in peat only and peatmoss + pine needles (5.2) while hieger in peatmoss + sawdust and peatmoss + rice hulls (5.4 and 5.9, respectively). Plant vigor and fruit set were good in both peatmoss only and peatmoss + pine needles treatments, leading to the increase in yield, but fruit quality was not influenced. The optimal mounding height in terms of plant growth and fruit number was found to be 15 ~ 20 cm. Overall root growth was highest with 15 cm mounding in which the number of vegetative branches developed averaged 8.3 per plant and roots weighed 385 g. Mulching materials affected soil water content and temperatures. Growth was good in both black polyethylene film and black non-woven fabric mulching treatments but black polyethylene film induced a slight winter injury (15%) on the current years growth. Consequently, fruit set and yield were higher in the black non-woven fabric mulching treatment than black polyethylene film. However fruit characteristics were not influenced.