• Horticultural Science & Technology
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• v.33 no.2
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• pp.202-209
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• 2015

In this study, we investigated the cumulative effect of low temperature on bud dormancy release and bud break characteristics in 'Campbell Early' grapevine (Vitis labruscana B.) cuttings grown in water culture. Additionally, we observed the development of buds while exposed to low temperatures in an attempt to improve our understanding of dormancy and bud break. The shoots were collected 120 days after full bloom (DAFB; leaf abscission period), and the accumulated chill unit (CU) value was calculated by reducing the temperature to $7.2^{\circ}C$ at 125 DAFB. The rate of bud break was 100% in shoots collected at 150 DAFB, The period until the first bud break was two times longer than in the shoots collected 165 DAFB, and bud break speed was significantly reduced. These results indicate that buds are released from endodormancy after 165 DAFB, because at this point the bud break was complete (bud break rate 100%) and it occurred in a very short time period. During this period, when the low-temperature accumulated value was 321h and 442CU according to the CH and Utah models, respectively. Furthermore, the survival rate of main buds decreased rapidly after 165 DAFB, and survival rate of accessory buds was maintained at more than 90% without seasonal differences. The rate of flower bud formation of main buds was much higher than in accessory buds (1:0.23) before the release from endodormancy at 150 DAFB. The final ratio of accessory buds to main buds was high, 1:1.54, at 255 DAFB. Correlation analysis of each investigated factor revealed that bud survival rate and bud formation rate were related only for the main buds, and there was a close relationship between the survival rate of main bud and time. In addition, the survival rate of main buds was positively correlated to the rate of flower bud formation.

• FLOWER RESEARCH JOURNAL
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• v.16 no.2
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• pp.134-142
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• 2008

This work aims to obtain basic information for seed propagation of Hydrangea serrata for. acuminata. The germination percentage of the seeds taken on 15 November, 30 December, and 23 January was $90.0{\pm}4.16%$, $84.4{\pm}5.52%$, and $88.9{\pm}2.40%$, respectively. This suggest that seeds of Hydrangea serrata for. acuminata are non-dormant seeds. The optimum temperature for germination was $25^{\circ}C$ and light was necessary. Most of the growth parameters (shoot and leaf length, stem diameter, root length, no. of roots, T/R ratio, and fresh and dry wts.) were significantly greater at $25/20^{\circ}C$ and $25^{\circ}C$ than at the other temperatures. Low T/R ratio at relatively cool temperatures (15 and $20^{\circ}C$) was caused by suppressed top growth. In light quality treatment, red light (RL) significantly enhanced stem elongation. The greatest photosynthetic pigments (total chl, chl a/b, and carotenoid) were observed in seedlings grown in blue light (BL), followed by seedlings grown in RL+BL. When blue light was added, higher pigment contents were found. Effect of plug cell size (50, 72, 128, 162 and 200 cells) on the growth of seedlings was investigated. The highest top growth was observed in seedlings grown in 50 cell trays, followed by seedlings grown in 72, 128, 162, and 200 cell trays. However, there was no significant differences between 162 and 200 cell trays. Especially, smaller size leaves were observed in seedlings grown in smaller cell trays (lower volume and high plant density).

• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.4
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• pp.229-236
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• 2003

This pot experiment was conducted in order to observe the effects of application of combined micronutrients(T$_1$: control. T$_2$; Fe, T$_3$; Fe+Mn, T$_4$； Fe＋Mn＋Cu, T$_{5}$; Fe+Mn+Cu＋Zn, T$_{6}$；Fe+Mn+Cu＋Zn+Mo, T$_{7}$； Fe+Mn+Cu+Zn+Mo+B) on forage performance of pure and mixed cultures of orchardgrass and white clover. The first part was concerned with the changes in the growth, summer depression, and flowering of forage plants. The results obtained are summarized as follows: 1. The T$_3$and T$_{6}$ resulted in a wide chlorosis induced by the Fe-deficiency on orchardgrass. Chlorosis was significantly reduced by the T$_4$and T$_{5}$, whereas the T$_{7}$, T$_2$, and T$_1$showed normal growth without chlorosis symptoms. The T$_{7}$ resulted in the best growth of orchardgrass both in the pure and mixed swards. There was no chlorosis symptom on white clover. whereas the T$_1$, T$_2$and T$_{7}$ showed a relatively good growth with deep green leaf-colour compared with the other treatments in the pure culture. 2. In summer, a summer depression occurred in orchardgrass: this was significantly reduced by the T$_1$and T$_{7}$. The treatments with chlorosis symptoms in orchardgrass partly induced a lodging. Summer depression in white clover did not occur. 3. In the pure culture, the T$_{7}$ and T$_2$in white clover resulted in many flowers and flower-buds compared with the other treatments. The T$_{7}$, especially, showed a long blooming period and an early full bloom compared with the other treatments, whereas the T$_{6}$ and is showed inferior numbers of them. Only the T$_{7}$ resulted in more flowers than flower-buds, and above 1 in the flower/flower-bud ratio except the T$_{6}$ in the mixed culture. 4. It was recognized that the chlorosis of Fe-deficiency occurred not only from the unsuitable ratios of Fe/Mn and Fe/Mo but also from the unsuitable mutual ratios among the cations(Fe, Mn, Cu and Mn), between the anions(Mo and B), and their total ion concentration. It was observed the multiple interactions of Fe${\times}$Mn${\times}$Mo${\times}$B, and the distinct role of B as a regulator.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.419-427
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• 2012

This study was carried out to investigate the effect of two shading methods, shading agent spray on the glasshouse and internal shading screen treatment, on the growth and fruit quality of paprika (Capsicum annuum L. 'Cupra' and 'Coletti') in summer season cultivation. In the shading agent treatment, a commercial shading agent diluted with water at a ratio of 1 : 4 was sprayed on the roof of a glasshouse. In the internal shading screen treatment, a 10~20% shaded screen was used during the day time when the sun radiation was greater than $700W{\cdot}m^{-2}$. Compared to the unshaded control, photosynthetic photon flux density (PPFD) decreased in the greenhouse in the shading agent (SA) and shading screen (SS) treatments by 20% and 30%, respectively. Lower air temperatures and higher relative humidities were observed in the SA than in both the control and the SS treatment. Time to reach the break point of humidity deficit $8g{\cdot}m^{-3}$ was 2 hours late in the SA than in both the control and the SS treatment. Compared to control, both the SA and the SS treatments showed lower instantaneous temperatures of leaf, fruit, and flower by $2^{\circ}C$, $5^{\circ}C$ and $3^{\circ}C$, respectively. There were no differences in number of branches, stem diameter, and leaf size among treatments although both shading treatments promoted plant height in both cultivars. Botrytis infection ratio declined with the SA treatment by 14.7% in 'Cupra' and 22.1% in 'Coletti' as compared to that in the control. Shading increased fruit size in both cultivars, whereas no differences were observed in the number of locules and thickness of fruit tissue among treatments. Shading treatment increased mean fruit weight by a range of 10 to 15 g per fruit, while it decreased soluble solids contents as compared to that in the control. Similar Hunter values were observed among treatments, while fruit firmness increased slightly in shading treatments. Compared to the control, shading treatments improved marketable fruits by 11.7~22.6% and increased the number of fruits per plant by 4~9.2 in both 'Cupra' and 'Coletti'. The results of this study indicate that shading agent application on the roof of glasshouse would be one of the most effective options to reduce heat stress imposed on the paprika crop in summer cultivation, resulting in improved crop growth and fruit yield.

• Journal of Korean Society of Forest Science
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• v.62 no.1
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• pp.24-42
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• 1983

To develop Ilex cornuta which grow naturally in the southwest seaside district as new ornamental tree, the author chose I. cornuta growing in the four natural communities and those cultivated in Kwangju city as a sample, and investigated its ecology, morphology and characteristics. The results obtained was summarized as follows; 1) The natural distribution of I. cornuta marks $35^{\circ}$43'N and $126^{\circ}$44'E in the southwestern part of Korea and $33^{\circ}$20'N and $126^{\circ}$15'E in Jejoo island. This area has the following necessary conditions for Ilex cornuta: the annual average temperature is above $12^{\circ}C$, the coldness index below $-12.7^{\circ}C$, annual average relative humidity 75-80%, and the number of snow-covering days is 20-25 days, situated within 20km of from coastline and within, 100m above sea level and mainly at the foot of the mountain facing the southeast. 2) The vegetation in I. cornuta community can be divided that upper layer is composed of Pinus thunbergii and P. densiflora, middle layer of Eurya japonica var. montana, Ilex cornuta and Vaccinium bracteatum, and the ground vegetation is composed of Carex lanceolata and Arundinella hirta var. ciliare. The community has high species diversity which indicates it is at the stage of development. Although I. cornuta is a species of the southern type of temperate zone where coniferous tree or broad leaved, evergreen trees grow together, it occasionally grows in the subtropical zone. 3) Parent rock is gneiss or rhyolite etc., and soil is acidic (about pH 4.5-5.0) and the content of available phosphorus is low. 4) At maturity, the height growth averaged $10.48{\pm}0.23cm$ a year and the diameter growth 0.43 cm a year, and the annual ring was not clear. Mean leaf-number was 11.34. There are a significant positive correlation between twig-elongation and leaf-number. 5) One-year-old seedling grows up to 10.66 cm (max. 18.2 cm, min. 4.0 cm) in shoot-height, with its leaf number 12.1 (max. 18, min), its basal diameter 2.24 mm (max. 4.0 mm, min. 1.0 mm) and shows rhythmical growth in high temperature period. There were significant positive correlations between stalk-height and leaf-number, between stalk-height and basal-diameter, and between number and basal diameter. 6) The flowering time ranged from the end of April to the beginning of May, and the flower has tetra-merouscorella and corymb of yellowish green. It has a bisexual flower and dioecism with a sexual ratio 1:1. 7) The fruit, after fertilization, grows 0.87 cm long (0.61-1.31 cm) and 0.8 cm wide (0.62-1.05 cm) by the beginning of May. Fruits begin to turn red and continue to ripen until the end of October or the beginning of November and remain unfading until the end of following May. With the partial change in color of dark-brown at the beginning of the June fruits begin to fall, bur some remain even after three years. 8) The seed acquision ratio is 24.7% by weight, and the number of grains per fruit averages 3.9 and the seed weight per liter is 114.2 gram, while the average weight of 1,000 seeds is 24.56 grams. 9) Seeds after complete removal of sarcocarp, were buried under ground in a fixed temperature and humidity and they began to develop root in October, a year later and germinated in the next April. Under sunlight or drought, however, the dormant state may be continued.

• Journal of Bio-Environment Control
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• v.15 no.4
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• pp.385-389
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• 2006

This study was carried out to determine the effect of raising seedling at Hallasan area of sub-alpine (altitude of 600m above sea level) to improve fruiting.ate of Squash (Cucurbita maxima) in retarding culture. 'Ebis' cultivar was seeded in plug tray of 32 cells and the seedlings were grown for 25 days. They were transplanted on August 26, 2004, following L-stem training method under rain-shielding condition. Seedling height, number of nodes and leaf area were higher in lowland than in sub-alpine area. T/R ratio of seedling in sub-alpine was much lower as compared with that in the lowland. The first fruiting was on the 19th node in sub-alpine area, and on the 26th node in the lowland area(control). The succeeding fruiting nodes were lower by 3 to 5 node than those of control. Fruiting rate of second flower was improved by 17.2% compared with the 1.4% in control. The marketable yield was increased by 27% by raising seedling in sub-alpine area (4,460 kg/10a). This also brought out 20% labour saving effect. The environmental condition for raising seedling in the sub-alpine area of Hallasan was effective for the improvement of Squash (Cucurbita maxima) fruiting rate compared with lowland area.

• Journal of Bio-Environment Control
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• v.26 no.3
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• pp.227-234
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• 2017

This study aimed to investigate the nutrient solution developed by based on nutrient-water absorption rate of strawberry 'Maehyang' by comparing growth and yield for 8 months with 5 kinds of nutrient solution with different ion composition. Strawberry plants were planted at elevated bed and supplied with five kinds of nutrient solutions (RDA), Yamazaki, PBG, University of Seoul (UOS) and NewUOS from one month onwards. Five types of nutrient solution were supplied to the strawberry plants associated with EC $1.0dS{\cdot}m^{-1}$, pH 6.0, $150{\sim}300mL{\cdot}plant^{-1}$ per day. At 60 days after planting, leaf width and leaf petiole of the strawberry plants showed significant differences among nutrient solution types and photosynthesis was higher in RDA and NewUOS nutrient solution and lower in PBG nutrient solution. The EC of the drainage on vegetative growth stage was $0.7{\sim}0.8dS{\cdot}m^{-1}$, which is lower than the supplied EC level, and to $1.0-1.2dS{\cdot}m^{-1}$, afterwards. The pH of the drainage was higher in Yamzaki solution as 6.2~6.8, while the pH of the UOS nutrient solution was lower in 5.1~5.2. Nitrate content was most absorbed in vegetative growth stage and after flower clusters development. The potassium uptake was highest at the NewUOS followed by UOS and Yamazaki nutrient solution. At six months after -planting fresh weight and dry weight of shoot and root were higher in UOS and NewUOS nutrient solution than other nutrient solutions, and the dry matter ratio was lower at 43.5% in Yamazaki nutrient solution and 30.6% in NewUOS nutrient solution than other solutions. Length, width, weight, and sugar content of the strawberries harvested from December to February were unaffected by treatment, but yield was higher in NewUOS nutrient solution due to increasing fruit number and average weight. From March to May, number of fruit was higher in Yamazaki nutrient solution. In conclusion, there was no difference in the growth of 'Maehyang' when 5 nutrient solutions were grown under hydroponics. But in order to improve the marketability, the NewUOS nutrient solution is appropriate to use from planting to February and it is suitable to use Yamazaki nutrient solution after March when temperature is high and the amount of fruit set per inflorescence.

• Korean Journal of Organic Agriculture
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• v.27 no.1
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• pp.33-44
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• 2019

This study was initiated to find possibility of substitute of gibberellin acid and to prevent negative girdling effect such as slow growth of 'Niitaka' (Pyrus pyrifolia Nakai) trees, a major pear cultivar, at harvest and at 60-, 90-, and 120-d after storage. Seasonal wiring with 3.0-mm-diameter were applied on the main branch at 70, 80, 90, 110, and 130 days after full bloom (DAF) to compare the fruit quality and storability. Fruit weight and sugar contents were the greatly increased by the wiring treatment at 110 DAF, with the lowest values observed for the wiring at 70 DAF. All the wiring treatments reduced fruit acidity but did not affect fruit firmness. a-value on fruit skin was the highest for wiring at 110 DAF and 130 DAF, advancing fruit ripening. The lowest fruit weight loss was occurred at wiring at 110 DAF. a-value on fruit skin was the highest for wiring at 90 DAF and 110 DAF. Wiring at 80 DAF the most increased floral bud diameter, resulting in the lowest L:D ratio of 1.74 observed. As for the mineral nutrients concentrations of floral buds, the concentration of K (0.63%) and Mg (0.31%) were the highest after 80 DAF wiring treatment, whereas Ca and P concentrations did not differ among treatment plots. The leaf K concentrations was the highest in the 130-day wiring treatment (0.76%) and in the control plot (0.78%), whereas there was no significant difference in the concentrations of either Ca or P among treatment plots. Short periods of wiring increased foliar Mg concentrations. In floral buds, carbohydrates showed a tendency for accumulating at a lower concentrations (7.75%) after 70 DAF wiring treatment, which was a relatively short treatment period. On the other hand, the carbohydrate concentrations in leaves showed a tendency for accumulating at lower concentrations after 130 DAF wiring treatment (2.51%), which is a long treatment period, and in the control plot (2.43%). Wiring increased the size and sugar content of fruits, and influenced fruit storability. For the wiring treatment period was delayed, the carbohydrate concentration in flower buds showed curvilinear correlation and the negative correlation with the carbohydrate in leaf tissue.

• Korean Journal of Breeding Science
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• v.42 no.6
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• pp.668-673
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• 2010

A new black seed coat soybean cultivar, 'Heugseong' was developed at the National Institute of Crop Science (NICS) in 2008. The goal to breed the black seed coat soybean is to develop the cultivar with large seed size, high yield, lodging tolerance, and resistance to disease such as soybean mosaic virus (SMV), and bacterial pustule. 'Heugseong' was selected from the cross between 'Gnome85', showing yellow seed coat, lodging tolerance, and high yield, and 'Cheongja', showing green cotyledon, and black seed coat. The preliminary, advanced and regional yield trials for this cultivar were carried out from 2004 to 2008. It has determinate growth habit, purple flower, brown pubescence, brown pod color, black seed coat, yellow cotyledon, elongated seed shape, oval leaf shape and large seed size (29.2 grams per 100 seeds). It was 4 days later in maturity than the check cultivar 'Ilpumgeomjeongkong'. 'Heugseong' was better than the check cultivar in the seed quality of isoflavone contents(1,913 ${\mu}g/g$). It has good adaptability for cooking with rice in ratio of water absorption and seed hardness, for physics of black tofu, and for fermented black soybean paste. The average yield of 'Heugseong' was 2.37 ton per hectare in the regional yield trials carried out in six locations of Korea from 2006 to 2008.

• Korean Journal of Breeding Science
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• v.42 no.3
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• pp.267-271
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• 2010

A new black seed coat soybean cultivar, 'Daeheug', was developed at the National Institute of Crop Science (NICS) in 2007. The breeding goal for black seed coat soybean is to develop the cultivar with large seed size, high yield, lodging tolerance, and resistance to disease such as soybean mosaic virus (SMV), and bacterial pustule. 'Daeheug' was selected from the cross between 'Daehwang' which had yellow seed coat, large seed size, and late maturity, and 'Milyang 79' which was lodging tolerant, and SMV resistant with medium seed size, black seed coat, and yellow cotyledon. The preliminary, advanced and regional yield trials for evaluation and selection of this cultivar were carried out from 2003 to 2007. It has determinate growth habit, purple flower, brown pubescence, brown pod color, black seed coat, yellow cotyledon, spherical flattened seed shape, oval leaf shape and large seed size (34.3 g/100 seeds). In maturity, 'Daeheug' was 2 days later than the check cultivar 'Ilpumgeomjeongkong'. In the seed quality such as isoflavone contents ($635{\mu}g/g$), and anthocyanin contents ($11.2m{\ell}/g$ of seed coat), 'Daeheug' was better than the check cultivar. It has good adaptability for cooking with rice in ratio of water absorption and seed hardness. Specially, it has good processability for soybean tea with 2.13 absorbance at 530 nm, scavenge activity of DPPH radical was high, and contents of total phenolics was $1,263{\mu}g/m{\ell}$. The average yield of 'Daeheug' was 2.26 ton per hectare in the regional yield trials (RYT) carried out in six locations of Korea from 2005 to 2007.