• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.3
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• pp.151-161
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• 2016

This study was conducted to find out influence of dormancy level and carbon concentration on freezing hardiness in bourse shoot of 'Fuji' apple tree. Bourse shoot of 'Fuji' adult apple tree grafted on M.26 and M.9 rootstocks were used as experimental materials. Dormancy levels of bourse shoot were categorized according to the periods as follows the internal dormancy (late January), the early days after internal dormancy breaking (early February), the late days after internal dormancy breaking (late February), the bud break (late March), and the full bloom (late April). Chilling temperatures with bourse shoot were ranged from 0 to $-40^{\circ}C$. Also, the freezing hardiness according to carbon concentrations were investigated on 'Fuji'/M.9 apple tree that defoliated severely by Marssonina blotch (defoliation) and that of below the average 20 cm in shoot length through heavy crop load (weakness). Results showed that freezing hardiness of bourse shoot may become weaker after internal dormancy breaking. There was no differences in the carbon concentration of bourse shoot of 'Fuji' apple tree grafted on M.9 and M.26, so may be resulted in no difference in freezing hardiness both of bourse shoot grafted on M.9 and M.26 rootstock. Carbon concentration in bourse shoots with weakness and C/N ratio in bourse shoots with defoliation were lower than that of healthy. It may be shown that the freezing hardiness of defoliation and weakness were weaker than that of healthy.

• Weed & Turfgrass Science
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• v.7 no.3
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• pp.231-238
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• 2018

This study was carried out to develope new zoysiagrass cultivars 'JangsungChorok' (Application No. :2013-3) and 'JangsungSaetbyeol' (Application No. :2013-4). One hundred and one genetic resources were collected at Jangsung Gun area from 2010 to 2011. Among the collected lines, CY6097 (JangsungChorok) and CY6069 (JangsungSaetbyeol) showed superior performance in spring green up and growth rate. 'JangsungChorok' showed genetically light green leaf color, with medium leaf width (4.4 mm), height from ground to first leaf blade of 3.2 cm and average plant height of 18 cm. Fast recovery rate and early spring green up rate will make this cultivar (JangsungChorok) for efficient sod producer. 'JangsungSaetbyeol' showed genetically dark green leaf color, with fine to medium leaf width of 3.5 mm, height from ground to first leaf blade of 4.3 cm and average plant height of 22.6 cm. Fast recovery rate and early spring green up rate with relatively narrow leaf will make this cultivar (JangsungSaetbyeol) for high sod quality.

• Journal of Sericultural and Entomological Science
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• v.18 no.1
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• pp.7-10
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• 1976

This experiments were carried out to know hatching power on treatments of cold temperature and hydrochioric acid Iron Late January to Early February. Used silkworm variety was Jam 103${\times}$ Jam 104 laying in Spring. The results may be summarized as follows: 1. The resting of silkworm eggs activated to Late January, to longer cold treatment was, the more effects of activating increased completely. So activated eggs were possible to incubation. 2. How to the light or short hours of hycrochloric acid were compare with heavy or long each other, it was inclined that the former seems to be worse than the latter. 3. On the interaction of cold treatments and hydrochloric acid, in case of short cold treatment, hatching power was better effect all treatments of hydrochloric acid than control, but no difference between specific gravity or treatment hours. On tile contrary, in case of more longer of cold treatments, hatching power depended not only upon the specific gravity, but also upon the treatment hours.

• Korean Journal of Medicinal Crop Science
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• v.9 no.2
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• pp.166-172
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• 2001

This study was conducted to investigate the optimum condition of breaking dormancy and to increase the germination rate of Hovenia dulcis Thunb. seeds. Germination of seeds which did not germinate at the various constant temperature was induced by the artificial breaking of seed coat, and the germination rate of seeds which the seed coats were broken was the highest(94%) at $15^{\circ}C$. The germination rate of seed was highest when seeds were treated with concentrated $H_2SO_4$ for 40 minutes. When seeds were stored in dry condition, the germination capability was maintained up to 5 years after harvest. However, their germination rate become lowered and average germinating duration was extended. Germination rate of seeds which were stored for 5 years significantly increased by the low temperature treatment more than 30 days.

• Journal of Bio-Environment Control
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• v.15 no.4
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• pp.417-420
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• 2006

To investigated the dormancy of chicory (Cichorium intybus L.) for production of high quality rootstocks, growth characteristics and abscisic acid (ABA) contents was conducted. The accumulation hours below $5^{\circ}C$ in field was increased slowly from October 7 to December 3, but there after increased largely. The rootstock weights was increased from the end of October to December 3, there after was not changed to December 3. ABA contents within the rootstock was not changed from October 7 to December 3, and there was suddenly increased for two weeks to December 24. As results of the sudden changed date of accumulation hours below $5^{\circ}C$, stopped date and period of rootstock growth, and sudden changed period of ABA contents, chicory has internal dormancy for two weeks from December 3 and low temperature requirement hours for the dormancy breaking is about 240.

• Korean Journal of Medicinal Crop Science
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• v.4 no.1
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• pp.64-67
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• 1996

This experiment was carried out to obtain the information on seed dormancy, germinability during storage in wasabia japonica Matsum. $GA_3$ 100ppm+BA 10ppm was more effective than $GA_3$100ppm alone in breaking the dormancy. Storage of seeds pretreated with growth retardants (CCC, Uniconazol) seemed to be a useful method for preventing germination during storage. The stratification was an effective storage method to germinate the seeds for sowing them in fall.

• Horticultural Science & Technology
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• v.19 no.4
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• pp.488-494
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• 2001

Seedlings of strawberry, 'Reiko' were planted in plastic pots of 24 cm in diameter in the middle of September in 1995, 1996, and 1997. Ten plants were transferred to greenhouse with artificial illumination at 5-day interval from late September to late January. The deepest dormancy of 'Reiko' in Daegu area was found to be on November 5, October 25, and October 31 in 1995, 1996, and 1997, respectively. The time for moving plants to make the plants grow in semi-dormant state in the greenhouse occurred between Nov. 10 and Nov. 20 in both 1995 and 1996, and between Nov. 10 and Nov. 30 in 1997. The time passing approximately 100-200 cumulative hours of exposure to below $5^{\circ}C$ canopy temperature from the peak dormancy, which is required for breaking dormancy of 'Reiko', was between November 16 and 25 in 1996, and November 24 and December 5 in 1997. 'Reiko' yielded high every year when seedlings were moved into greenhouse during the period of October to November. The plants gave good response to forcing culture under lighting. The right time for moving plants into greenhouse in semi-forcing culture appeared to be the time passing 50-150 cumulative hours of exposure to below $5^{\circ}C$ canopy temperature from the peak dormancy.

• Horticultural Science & Technology
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• v.33 no.4
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• pp.501-510
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• 2015

In this study, we investigated the onset and release of endo-dormancy under natural conditions by observing bud break characteristics in 'Fuji' apple trees using water cuttings. Through examinations of bud break rate and days to bud break, we found that the endo-dormancy of 'Fuji' apple tree continues for 70 d from 165 to 255 d after full bloom (DAFB), from late October to early January of the following year. In addition, within 20 d of first bud break, based on a final bud break rate of 60% or more, we able to identify the timing of the changeover from para-dormancy to endo-dormancy, and endo-dormancy to eco-dormancy. Analysis of the chilling requirement during the endo-dormancy period revealed that chilling accumulation up to 255 DAFB to release endo-dormancy amounted to 666 and 517 h based on the CH and Utah models, respectively. Observation of internal changes in the bud during endo-dormancy showed that flower bud differentiation begins from mid-July, and t ime of inflorescence o f the disk f lower is a vailable to f ind. The f lower buds subsequently developed slowly but steadily during endo-dormancy and in the following year in February, the developmental stage of each organ had progressed. Moreover, the flower buds of 'Fuji' apples were mostly healthy during the dormancy period, but some exhibited necrosis of flower primordium, due partial cell damage from the formation of ice crystals rather than a direct effect of the low temperature. Flower buds were formed in both the axillary buds of bourse shoots and terminal buds of spurs, but lower bud differentiation was observed for the terminal buds of spurs at rate of about 65% of total buds, which was directly related to the bud size and shoot diameter.

• Proceedings of the Korean Society of Crop Science Conference
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• 1986.06a
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• pp.82-83
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• 1986

• KOREAN JOURNAL OF CROP SCIENCE
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• v.22 no.2
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• pp.18-22
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• 1977

Germination ability of a japonica and 15 indica$\times$japonica varieties was tested at day/night tempuratures of 25/2$0^{\circ}C$ and 12/12$^{\circ}C$. Germination ability of a japonica variety, "Jinheung" and two indican$\times$japonica varieties. "Suweon ＃251" and "Suweon ＃278" was greater than that of other indica$\times$japonica varieties tested. Germination pattern of varieties was made into 4 groups.ieties was made into 4 groups.