• Journal of Plant Biology
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• v.17 no.2
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• pp.87-94
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• 1974

This survey has been carried out on ten species(Erythronium japonicum, Symplocarpus renifolius, Adonis amurensis var. ramosa, Corydalis turtschaninovii var. genuina, Primula sieboldii forma spontanea, Anemone raddeana, Gagea Iutea, Heloniopsis japonjca, Hylomecon japonicum, and Convallaria majalis var. keiskei in the undergrowth of a forest of deciduous broad-leaved trees in the Kwangnung area of Kyung-Ki Province. They always bloom towards the end of March which is earlier than most of the other plants do. They completely finish up their matter productions before foliage of the deciduous trees, which are the upper strata plants, grows broader or to cite in other terms, before the relative light intensity in the lower strata is fallen to the lowest degree to become to insufficient to allow for photosynthesis. These phanerophytes naturally wither down between June and July. The above mentioned phenomenon clearly demonstrates a kind of the ecological niches and habitat segregation in terms of using sunlight to her greatest advantage. Soon after these herbs wither they make their own winter buds-life form-around their roots and then go into hibernation. The intensity of light in this forest zone was measured through the use of a lux meter in order to investigate it's seasonal variations. In additions, an intensive survey on the duration of their efflorescence was fullfilled.

• Horticultural Science & Technology
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• v.17 no.2
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• pp.123-126
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• 1999

Effects of garlic juice (GJ), ethanol- (GJAE) and ethyl ether extract of garlic juice (GJEE), onion juice (OJ) and ethanol extract of onion juice (OJAE), garlic juice+Merit Blue (GJ+MB), ethanol extract of garlic juice+Merit Blue (GJAE+MB), onion juice+Merit Blue (OJ+MB), ethanol extract of onion juice+Merit Blue (OJAE+MB), and Merit Blue (MB) on budbreak, flowering, and maturity of plastic house-grown 'Daebong' grapes (Vitis labruscana B.) were studied. MB alone and in combination with other formulae hastened the budbreak, and double application was more effective than single one. Most of the buds sprouted in early forcing, but percent budbreak in late forcing was very poor except for MB application. In early forcing, single application of MB in combination with other formulae was most effective for hastening flowering while the response to double application was not consistent, and even delayed the flowering except for OJAE, MB, and OJ+MB. In late forcing, single application of all dormancy-breaking agents, especially MB in combination with other formulae, hastened the flowering while flowering response to double application was inconsistent, and even delayed the flowering except for OJAE+MB and OJ. Although there were no significant differences in harvest date among treatments and the number of application in early forcing, single and double application of MB alone and in combination with other formulae, especially double application of OJAE+MB hastened the harvest date for 12 days in late forcing culture.

• FLOWER RESEARCH JOURNAL
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• v.19 no.2
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• pp.89-95
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• 2011

This study was conducted to improve commercial quality of cut spray chrysanthemums 'Charming Eye' and 'Pink Pride' bred in Korea by foliar application of daminozide, suppressing excessive elongation of peduncle caused by high temperature in greenhouse. Applications were made at two floral-bud-developmental stages and concentrations used were 0, 500, 1000, and $2000mg{\cdot}L^{-1}$. As for 'Charming Eye', cut flower length, peduncle diameter, stem diameter, flower bud diameter, and the number of flower buds did not show any significant difference among all treatments including control. However, the suppressing effect of peduncle elongation, widening angle of flower cluster arrangement on apical part, and increasing parallel flower buds in stage I showed better than those in stage II regardless of daminozide concentration. As for 'Pink Pride', cut flower length, peduncle diameter, and stem diameter did not show any significant difference among all treatments including control but angle of flower cluster on apical part increased compared to control as daminozide was sprayed at stage I and II except $2,000mg{\cdot}L^{-1}$ daminozide-sprayed at stage II. The number of flower buds and flower bud diameter showed the greatest increment through $1,000mg{\cdot}L^{-1}$ daminozide-sprayed at stage I and did the least values as sprayed with $2,000mg{\cdot}L^{-1}$ daminozide at stage II. Daminozide also gradually reduced peduncle length in a concentration-dependant manner but elongation of peduncle foliar-sprayed at stage I showed the more suppressing effect than that at stage II. Increasing the number of parallel flower buds showed the best results when sprayed with $2,000mg{\cdot}L^{-1}$ at stage I. In conclusion, we recommended that foliar spraying with $500-1,000mg{\cdot}L^{-1}$ daminozide at stage I and foliar spraying with $1,000-2,000mg{\cdot}L^{-1}$ daminozide at stage I improved cut flower quality of 'Channing Eye' and 'Pink Pride', respectively.

• Journal of Korean Society of Forest Science
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• v.103 no.2
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• pp.153-158
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• 2014

To examine the natural regeneration in the natural mixed-broadlived forest, flowering, fruiting, seed-fall, and seed viabilities of Acer ukurunduense Trautv. & C.A. Mey. (AU) were investigated in Mt. Jungwang, Gangwon-do, from 2009 to 2013. The flower of AU consisited many male and bisexual flowers on the raceme (unusual panicle) and the arrangement of two sex morphs are differed for each inflorescence. Flowering dates are differed between sex morph in the same inflorescence. Stamens are stop growing and disappeared after pollinated pistil begin to grow in bisexual flowers, and male flowers have vestial pistil. The flowers of AU might be pollinated by Apis mellifera, Thyris fenestrella seoulensis, Cerambycidae sp., Andrenidae sp. and Ctenophora sp., and had some mechanism to prevent feom self pollination. The number of flower buds per inflorescence is 189 on June 8, and that of young samaras per inflorescence is 41.2 on June 21. At last ripened samaras per inflorescence is reduced 33.4 on September 5. Mean annual seedfall of AU was 6,720 ea/ha (ranged 670~17,930). Rates of sound seeds are highest 43.2%, and those of damaged or decayed seeds are 41.8%,. Those of undeveloped and empty seeds are 10.2% and 4.8%, respectively. Successful regeneration of AU might be in masting year and on the gap sites with proper conditions to germinate and grow. To understand the natural regeneration of the species, Genus Acer, further study on the fruiting habit, pre- and post-dispersal seed viability, and annual variation on these factor should be needed.

• Journal of Korean Society of Forest Science
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• v.104 no.2
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• pp.179-186
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• 2015

This study was conducted to understand the characteristics of flowering and the factors affecting fruiting grades of Acer pictum subsp. mono(APSM), We examined the characteristics of flowering and fruiting in various natural APSM forest, and investigated annual fruiting grade, DBH, tree height, number of APSM trees within 30 m on 29 selected trees in the natural broadleaved forest in Mt. Jungwang in Gangwon-do, from 2009 to 2014. APSM has heterodichogamous sexual system consist of protoandry and protogyny. Eight trees have changed their sex morphs; 3 trees change the sex morph PA to PG, and 5 trees does the sex morph PG to PA. Early fall of young ovary is concentrated until early July. Initially, the small samaras are common, and was gradually increased the samaras suffered insect damage. Most flowers of APSM are pollinated by Andrenidae sp., Syrphidae sp. and Tachinidae sp.. Number of early fall samaras and the status of fallen samaras showed a significant difference by the year and region. Corymbose panicle and young leaves developed on the top of APSM twigs. Newly grown opposite twigs of APSM did not grow sufficiently and had no floral buds. The highest fruiting grade of tree was 9.0, and the mean values was only 3.8. The highest fruiting grade of year was 4.55 in 2013, and the lowest did 0.07 in 2014. Highly significantly correlated and regressed between mean of annual fruiting rates and rates of crown under sun light. This results would imply that thinning for tree growth through improved light absorption might be a method to enhance seed production of APSM in the seed production forest.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.4
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• pp.268-278
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• 2020

Flowering time has been put forward due to the recent abnormally warm winter, which often caused damages of flower buds by late frosts persistently. In the present study, cumulative chill unit and cumulative heat unit of Niitaka pear, which are required for releasing the endogenous dormancy and for flowering after breaking dormancy, respectively, were compared between flowering time prediction models used in South K orea. Observation weather data were collected at eight locations for the recent three years from 2018-2020. The dates of full bloom were also collected to determine the confidence level of models including DVR, mDVR and CD models. It was found that mDVR model tended to have smaller values (8.4%) of the coefficient of variation (cv) of chill units than any other models. The CD model tended to have a low value of cv (17.5%) for calculation of heat unit required to reach flowering after breaking dormancy. The mDVR model had the most accurate prediction of full bloom during the study period compared with the other models. The DVR model usually had poor skills in prediction of full bloom dates. In particular, the error of the DVR model was large especially in southern coastal areas (e.g., Ulju and Sacheon) where the temperature was warm. Our results indicated that the mDVR model had relatively consistent accuracy in prediction of full bloom dates over region and years of interest. When observation data for full bloom date are compiled for an extended period, the full bloom date can be predicted with greater accuracy improving the mDVR model further.

• Horticultural Science & Technology
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• v.17 no.3
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• pp.333-336
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• 1999

Current season's shoots on 2-year-old branches of 'Fuji' and 'Jonagold' apple trees were heading back pruned to 5 leaves from early May to mid July at about 12-day intervals. The summer heading back pruning induced regrowth on the pruned shoots with different responses between the two cultivars. Generally, greater regrowth occurred on the pruned shoots of 'Fuji' trees than on those of 'Jonagold', irrespective of the time of the heading cut. The shoots of 'Fuji' trees pruned in late May or in June exhibited greater regrowth compared with those pruned in early May or in July, whereas the summer heading back pruning in June resulted in the greatest regrowth for 'Jonagold'. The heading cut induced terminal flower bud formation on the pruned shoots, the percentage of which was higher in 'Fuji' than in 'Jonagold'. The highest percentages of terminal flower bud formation for 'Fuji' and 'Jonagold' were obtained with the heading cut in late May and in mid June, respectively. Percent flowering of the buds was similar in both cultivars, but percent fruit set was slightly higher in 'Fuji' than in 'Jonagold'. The time of the heading cut did not affect percent fruit set in both cultivars. Our results demonstrate that summer heading back pruning of current season's shoots induces regrowth and terminal flower bud formation therefrom when done at appropriate time, but the specific responses to the heading cut are cultivardependent.

• Research in Plant Disease
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• v.10 no.4
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• pp.290-296
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• 2004

Bacterial blossom blight is one of the most important diseases of kiwifruit (Actinidia deliciosa). The disease occurs during flowering in the late May and disease outbreaks associated with rainfall during the flowering season have resulted in a severe reduction in kiwifruit production. The causal organism isolated from diseased blossoms of kiwifruits was identified as Pseudomonas syringae pv, syringae based on the physiological and biochemical characteristics and pathogenicity test. Dead fruit stalks, dead pruned twigs, fallen leaves and soils mainly provided R syringae pv. syringae with overwintering places in the kiwifruit orchards, and the inocula also overwintered on buds, trunks, branches, and twigs on the kiwifruit trees. Among the overwintering places, the incula were detected in the highest frequencies from dead fruit stalks. The population density of P. syringae pv. syringae was speculated to be over $1{\times}10^4$cfu/ml for the bacterial infection, and the optimum temperature for the bacterial growth ranged 20 to $25^{\circ}C$. The highest population density of P. syringae pv. syringae on the overwintering places was detected in May and June when the daily average temperature coincided with the optimum temperature for bacterial growth of P. syringae pv. syringae.

• Journal of Crop Science and Biotechnology
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• v.11 no.1
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• pp.23-30
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• 2008

The relationship between three phenological parameters and somatic embryogenesis was investigated during a two-year period. Staminodes and petals from six hybrids and two clones as controls were sowed on three distinct primary callus growth media. Flowering level, fructification level, and leaf thrusts rhythm as phenological parameters were measured simultaneously during the weekly harvest of flower buds. Mean and coefficient of variation of the measured parameters highlighted stable phenological phases. The relationship between phenological parameters and somatic embryogenesis was investigated first by comparing the variation of somatic embryogenesis and that of the phenological parameters, and second by using Pearson's linear correlation. Except for the fructification level in both control clones the first year, the other parameters recorded stable phenological phases, regardless of the genotype and year. Favorable and unfavorable phases for the somatic embryogenesis were identified. In hybrids, favorable phases included February, August, September, and October. In both control clones, time interval propitious to embryogenesis stretched from February to December. The significance of the coefficient of correlation seemed to establish a relationship between somatic embryogenesis and phenology. However, a causal link could not be established. Leaf thrusts rhythm was revealed to be the phenological parameter most linked to somatic embryogenesis. Attempts to optimize embryogenesis during unfavorable phases, showed that a correction of 2.4 D/TDZ concentration is not the solution.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.5 s.112
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• pp.94-103
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• 2005

This study was carried out to investigate growth and morphological characteristics of leaf, flower and winter bud of Corylopsis species such as C. coreana, C. spicata, C. sinensis, C. willmottiae, C. willmottiae 'Spring Purple', C. wilsonii, C. spicata 'Yellow Spring', C. gotoana, and C. vechiana. In the Corylopsis species, C. coreana, C. willmottiae, and C. vetchiana had larger flowers, longer flower cluster, and more flowers than other species. C. sinensis and C. veitchiana had fragrant flowers. In addition, species with beautiful leaf color were C. spicata 'Yellow spring' with yellow color and C. willmottiae 'Spring purple' with purple color, which eventually changed to green. The winter bud of C. sinensis, C. willmottiae, C. willmottiae 'Spring Purple', and C. vechiana were oval and different from those of other species. Comparison of the morphological characteristics among C. coreana, C. spicata, and C. sinensis, C. coreana showed they had earlier flowering dates and brighter yellow flowers than those of other species. Flower cluster of C. sinensis was shortest, but it had most number of flowers and fragrance. In addition, the winter buds of C. coreana and C. spicata with elliptical shape were different from that of C. sinensis with oval shape. Therefore, based on these characteristics, the following Corylopsis species were found to be promising as woody landscape plants: C. coreana, C. sinensis, C. willmottiae 'Spring Purple', C. spicata 'Yellow Spring', and C. vechiana.