• The Journal of the Convergence on Culture Technology
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• v.5 no.1
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• pp.347-352
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• 2019

We analyzed the correlation among fruit bearing branch (FBB) and shoot and fruit characteristics in order to select the length of FBB suitable for producing high-quality fruits of 'Soomee', a peach tree developed in Korea. The length and diameter of FBB were 26.1 cm and 6.1 mm, respectively, shoot and leaf number per FBB were 3.2 and 38.6, respectively. Of these, the coefficient of variation was very high in the shoots and leaf number. The average weight and soluble solid content (SSC) of fruit were 298.6 g and 12.2 Brix, respectively, and coefficient of variation of the fruit weight was 18.0 %, which was higher than that of SSC. As the FBB of 10-20 cm and 20-30 cm length per tree were 27.1 % and 25.4 %, respectively, the sum of short and middle FBB frequency per tree was more than 50 %. Fruits of 250-350 g and 11.0-13.0 Brix per tree were distributed in 68.6 % and 74.0 %, respectively. As a result of correlation analysis, fruit weight and shoot number were affected by the length of FBB. In particular, length of FBB showed the relation of fruit weight with $y=-0.0482x^2+2.4512x+277.36$. As a result, the length of FBB that can maximize fruit weight was analyzed as 25.4 cm. Therefore, in the filed, the suitable FBB for producing 'Soomee' peach is estimated to be about 20-30 cm.

• Korean Journal of Breeding Science
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• v.40 no.4
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• pp.371-376
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• 2008

For the purpose of breeding a high-yield superior variety of Korean raisin tree (Hovenia dulcis var. koreana Nakai), whose value as an edible and medicinal resource is increasing, tree candidates for superior individuals were selected from its 11 habitats in Korea from 1996 to 1998. A clone bank preserve was created in 1998 with 70 clones proliferated by grafting; the fruition traits (e.g., the number of fructified laterals, the average number of bunches per fructified lateral, the average number of bunches per fruiting lateral, the fruitpetiole weight per individual, and the yield per individual) of 47 clones that had bloomed and borne fruit were investigated and analyzed in 2002; five upper-ranking clones whose yield per individual exhibited a 261% improvement against the total average were picked in 2005; and three clones, including 'Poong-Sung 1', that showed a difference in their fruit petiole ripening stage, were finally selected in 2007 as high-yield new cultivars of Korean raisin tree.

• Korean Journal of Plant Resources
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• v.21 no.6
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• pp.431-434
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• 2008

Dental caries is the destruction of the enamel of teeth by Streptoccus mutans. S. mutans has been isolated from human dental plaque and is associated with the initial development of enamel lesions. We have studied the antibacterial action of the fruit of Callistemon citrin us against a cariogenic bacterium, S. mutans. From the fruit of C. citrinus, piceatannol (3,3',4',5-tetrahydroxystilbene) was isolated by repeated column chromatography with $SiO_2$ and Sephadex LH-20. Its structure was elucidated by instrumental analysis using 1D-NMR, 2D-NMR and EI-MS. This compound was isolated from the fruit of C. citrin us for the first time. The anticarcinogenic activity of this compound was determined by using agar well-diffusion method and minimal inhibition concentration (MIC).

• Journal of Korean Society of Forest Science
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• v.103 no.2
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• pp.196-202
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• 2014

In order to select superior trees based on fruit characteristics and provide basic informations necessary for their improvement, total 107 individual trees of Sorbus alnifolia (Sieb. et Zucc.) K. Koch were selected from 11 wild populations in South Korea. After collecting normal fruit branch, we investigated morphological characteristics of fruit and then considered its relationship among the 11 populations by multivariate analysis method. Results from principal compound analysis showed that it represented 85.8% accumulated explanation from five principal compounds. According to cluster analysis based on fruit characteristics, the natural S. alnifolia populations were classified into four groups and Mt. Mani population was different from other populations. Selection effect with outstanding candidate trees including superior 5 individual trees (Gwangyo 1, Gwangyo 2, Deogyu 7, Mani 29, Mani 30) was estimated at 122.8%, 115.5% and 182.7% in fruit width, length and yield per fruit bunch, respectively. The object of this results will give us invaluable information about breeding by selection of S. alnifolia in south Korea.

• Horticultural Science & Technology
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• v.19 no.1
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• pp.60-65
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• 2001

'Shinil' pear cultivar (Pyrus pyrifolia Nakai) which was originated in a cross between 'Shinko' (non-patented, released in 1941) and 'Hosui' (non-patented, released in 1972) in 1978 was released as a middle season harvest variety. Its usual picking time coincided with 'Chuseok' season which is one of the most famous national holiday in Korea. The fruit showed high soluble solids content and good appearance. The cultivar was preliminarily selected in 1991, and its regional adaptability was evaluated in the name of 'Wonkyo Na-13' at 9 sites for four years from 1992, and finally selected and named in 1995. 'Shinil' is medium in tree vigor like 'Hosui' and spreading in tree habit as 'Niitaka', a leading cultivar in Korea, and consistently very productive. It has high resistance to black rot caused by Alternaria kikuchiana and pear necrotic spot caused by pear necrotic spot virus. Its full bloom is one day earlier than that of 'Niitaka' cultivar and harvest time is September 25 at Suwon area which is 3 days later than that of 'Hosui'. Fruit is round in shape with a deep medium stalk cavity and medium calyx basin and has attractive light yellow brown skin color. The fruit weight ranges between 300 and 400 g, which is similar to 'Chojuro', 'Shinko', and 'Hosui'. Soluble solid content is approximately at the level of 13-14 Brix, which is higher than that of 'Chojuro'. The flesh is cream-white, very juicy, and light grit with soft and fine texture.

• Korean Journal of Environmental Agriculture
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• v.37 no.2
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• pp.87-96
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• 2018

BACKGROUND: The vigorous shoot growth in upper part of apple tree canopy leads to poor fruit quality and flower bud formation in lower part of canopy. So, this study was conducted to develop the proper control method about the shoot growth in upper part of apple tree canopy. METHODS AND RESULTS: Trunks of 'Fuji'/M9 apple trees were cut (back pruned) to 2.5 m in tree height on 11 February (dormant) or 12 April (full bloom). Naphthalene acetic acid (NAA) was applied at 2.0% to cut surface when trunk was pruned. Prohexadione-calcium (Pro-Ca) was sprayed at 250 mg/L above 2.0 m in tree height at 23 April (petal fall). The NAA or Pro-Ca application after trunk was pruned at dormant (TR-2 and TR-3) significantly reduced shoot growth in upper part of canopy compared with the control (tree was only pruned at dormant, TR-1), but the percent of shoots showing the secondary growth of TR-3 was higher over 2 times than that of TR-2. The reduction of shoot growth in upper part of canopy by TR-2 and TR-3 increased the fruit red color from the lower part in the treating year and blooming of the lower part in the following year. CONCLUSION: Applying 2.0% NAA to cut surface of pruned apple trunk at dormant was the most effective way for stabilization of the tree vigor in upper part of the canopy in a high density apple orchard.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.231-231
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• 2005

• Horticultural Science & Technology
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• v.28 no.4
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• pp.552-560
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• 2010

$GA_{4+7}$+BA, a plant growth regulator for induction of feathering in young apple tree and increasing fruit size, was applied by various methods on 'Gala'/M.9 apple trees in high density orchard for 4 years to investigate its effect on fruit and shoot growth. $GA_{4+7}$+BA($80-300mg{\cdot}L^{-1}$) increased fruit length, fruit weight, and L/D ratio regardless of application methods, but it did not affect soluble solid content, acidity, leaf area, and chlorophyll. Seed number was not affected by $GA_{4+7}$+BA application, however, more immature seeds was observed in treated 'Gala' fruit. Shoot growth was increased when spraying $GA_{4+7}$+BA at tree crown but not affected when spraying at fruit directly. More significant fruit growth was observed when $GA_{4+7}$+BA was applied on the fruits between late of May and early of June when fruit cell division ended; however, high concentration of $GA_{4+7}$+BA resulted in lower fruit storability because of lower firmness. Hence, more attention should be paid when applying high concentration of $GA_{4+7}$+BA to small sized fruit cultivars like 'Gala'.

• Korean Journal of Agricultural Science
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• v.49 no.3
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• pp.421-430
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• 2022

Crop load management in apple trees is important for achieving optimum productivity and crop value. Hence, we investigated the influence of different crop loads on the fruit quality, mineral content, and yield of the 'RubyS' apple variety. After 4 weeks of full bloom, the crop load was adjusted by hand thinning to different (5, 10, and 15 fruits·cm^-2) trunk cross-sectional areas (TCSA), representing low, medium, and high crop loads. The low crop load increased the fruit size and weight, the development of the red-blushed area, and the peel color a^* at harvest; however, it reduced the total number of fruits·tree^-1 and yield compared with that of the other crop loads. The medium crop load improved the fruit weight, flesh firmness, and soluble solids content and reduced the fruits·tree^-1 but did not affect the fruit size and yield. However, there were no significant differences in the titratable acidity and starch index among the crop loads. The fruit mineral content (phosphorus and potassium) was higher in the low and medium crop loads compared to the high crop load. However, the nitrogen, calcium, and magnesium contents in the fruits were not affected by the crop loads. Overall, this study suggests that a low crop load improves the fruit size and weight, but its effect on the quality and fruit mineral content is similar to that of a medium crop load. Therefore, the optimum crop load level for the 'RubyS' apple trees was approximately 10 fruits·cm^-2 TCSA.

• Korean Journal of Plant Resources
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• v.37 no.4
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• pp.401-410
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• 2024

This study was undertaken to elucidate the effects of virus and viroid infections on the growth of trees and the attributes of fruit quality in 'Hongro' apples. Trials were initiated using virus-infected, viroid-infected, combined virus/viroid-infected, and uninfected apple trees in an experimental apple orchard at the National Institute of Horticultural and Herbal Science in 2019. The growth of each tree was measured annually and compared between virus-free and virus/viroid-infected trees. Fruits were harvested from all apple trees, and selected attributes of fruit quality, including yield, weight, firmness, titratable acidity, and anthocyanin content, were determined in September 2021-2022. The results revealed significant differences among virus-free trees and those infected with either virus, viroid, or a combination of virus and viroid. Infection with viral and viroid diseases led to reductions in tree height (14.0%), trunk area (23.1%), fruit yield (65.0%), fruit weight (34.4%), and anthocyanin content (39.8%), while increasing fruit firmness (33.2%) and titratable acidity (39.8%), respectively. We anticipate that our research findings will also be beneficial for apple virus and viroid disease control, as well as apple cultivation management.