• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.6
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• pp.71-85
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• 2011

In Okdong coal mine abandoned area, every year large amount of mine wastes have been swept away due to heavy rains in summer. Because pH of coal-mine waste is in the early 4, plant naturally does not grow there due to unfavorable condition for growing plant. This study had an experiment to grow plant for 6 months using Mycorrhizae which can be adapted well in acid soil. As a result of Experiment, In the infected experiment pot, 90% of the plants survived but in case of uninfected experiment pot, only 25% were alive. From Growth Experiment, it appeared that average stem length increase (cm/month), average fresh weight increase ($g^{fw}/month$), average dry weight increase ($g^{dw}/month$) were increased by 60%, 21%, 31% respectively. Especially, Mycorrhizae plays an important role in providing nutrients and water when seeding are established. Mycorrhizae prevents death caused by lack of nutrients and water and helps growth and development of plant when seeding are established in the early stage. This study proved that Mycorrhizae is comparatively effective in plant growth and prevention of erosion in coal-mine abandoned area.

• Korean Journal of Medicinal Crop Science
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• v.4 no.2
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• pp.163-171
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• 1996

The influences of temperature, harvest time, sowing time, seeding media, moisture content of media and light on the seed germination of Lycoris are as follows, Both L. koreana and L. aurea had over 90% seed setting, and seed maturity came in September or early October. It took six months to have over 60% seed germination. The optimum germination temperature was $25^{\circ}C$, and the alternating treatment was effective at $20{\rightleftarrows}25^{\circ}C$. The optimum harvest-time was around Sep. 20, and the optimum seed-time was immediately after havest. The optimum seeding media was sand loam, and the optimum moisture content was PF 1. 9/400ml seeding media. The dark condition was more effective for the seed germination than the light condition.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.4
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• pp.466-472
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• 1997

Vegetable perilla, "Ipdlkkae 1"(Perilla frutescens var japonica Hara), was tested about the flowering and maturing responce in summer and winter. In summer season, it was researched about those responses according to the change of seeding date from May 15th to Oct. 15th at one month interval in the field. "Ipdlkkae 1" flowered Oct. 2nd under the day length of eleven hours and fourty-one minutes, compared with Sep. 6th (day length of twelve hours and fourty-three minutes) of "Yepsildlggae". And those responses showed that vegetable perilla was have to seeded before July 15th for two reason. The first is a unique response of perilla to day length. If perilla stay under short-day condition for some days, perilla will flower after four weeks. The second is a weather, especially frost and cold. In the test of latest seeding at Oct. 15th, the plants flowered more late than normal flowering period and they were not able to mature for frost of early winter. And this result showed that any other species, which has the characteristic of later flowering than that of "Ipdlkkae 1", could not able to mature in the field. In winter time, this species was tested about the same responses according to the change of short-day treatments. In the case of the test from May 1st (above fourteen hours day length), even if the test plants were stayed under short-day condition for more than 10 days, they were not able to mature, but flowerd. From the test of Apr. 15th, day length of thirteen hours, the plants were showed variable reaction to the short-day treatment. In this test, 11days for short-day treatment was a basic day to decide whether flowering was delayed or not. In the test from Apr. 1st, perilla seeds were able to harvest at least 5 days short-day treatment. In the final test from Mar. 15th, it had no need to take short-day treatment for harvesting of normal seeds, because the day length of that are twelve hours, which is an enough time to induce flowering and maturing, previously reported.

• Korean Journal of Environment and Ecology
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• v.17 no.4
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• pp.309-315
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• 2004

To estimate planting results of deciduous broad-leaved species, forest structure and radial growth of the trees were investigated and compared by species and studied sites. Plantation forest studied on Juglans mandshurica, was located at Jawoon-ni Nae-myeun, Hongcheon-gun and natural forest studied on Juglans mandshurica, was located at Jangjeon-ni Jinbu-myeun, Pyeungchang-gun. In 9 years after planting, differences of annual diameter increment among three stand origins were significant. The highest mean annual diameter increments of J. mandshurica, 7.31mm/year was measured in natural seedlings, and followed by sprouting trees 6.93mm/year. The lowest values, 5.28mm/year did in planting trees. Early radial growth of planting J. mandshurica was measured lower than that of sprouting or natural seedlings. These facts means that planting J. mandshurica is not proper regeneration methods. Other regeneration methods of J mondshurica forest, by sproutings, direct seeding and natural seeding, might be researched and recommended.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.2
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• pp.185-191
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• 1981

The purpose of this paper is to define and describe a series of growth stages for maize. cv. MTC-l (early) and Suweon No. 19 (late) that are easily identifiable by both professional agronomists and farmers. Plants were grown at a density of 60cm row with plant spacing of 15cm at six different seeding times in 1980. Leaf development indices with ten grades (LDI) were identified and defined in accordance with the development of a leaf blade. Leaf appearance rate (LAR) was ca. 3 days and it was not influenced by the variety or seeding time. The elongation of the first internode above the ground level began in a month after emergence and it corresponded to the 8th or 9th leaf stage. Internodes elongated in regular sequence of node position. The morphological change of silks related closely with the development of kernel. The duration of generative development was not influenced by varieties and seeding time but that of vegetative growth was influenced. A new scheme for the maize which was made by the developed leaves, visible nodes above ground level, morphological change of silks and development of kernel was proposed.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.132-132
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• 2022

The application of direct seeding cultivation reduces time, labor, and cost. However, this application often has poor seedling establishment and leads to lower yield as compared to transplanting system. The tolerance to anaerobic and low temperature germination is important to improve seedling establishment and the wide-spread application of direct seeding method. This study was carried out to evaluate the responses of three japonica cultivars to different temperatures (15℃, 18℃, 21℃, 24℃, and 27℃) and different flooding levels (1 cm, 4 cm, 7 cm, 10 cm) during germination and seedling development. The mean survival percentage significantly increased (P<0.05) when the flooding level decreased and when temperature increased. There were significant effects of the interaction between temperature and water depth on survival percentage and seedling height. When temperature decreased from 27℃ to 15℃, the germination duration significantly increased from 6.4 days to 16.3 days while the germination speed, survival percentage, and seedling height decreased from 5.3 seeds day^-1, 61.9% and 190.6 cm to 2.2 seeds day^-1, 33.2%, and 47 cm, respectively. The increase in temperature under submergence condition was associated with the increased expression of Amy3D and ALDH2a but the decreased expression of ADH1 and PDC1. The results of this research would be used for further studies and breeding programs to improve rice seedling establishment and the application of direct seeding cultivation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.4
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• pp.460-472
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• 1995

This study was aimed to provide understanding on the eco-physiological response of barley tillers as affected by difference in seeding date. Yield and yield contribution rates of tillers were investigated with the data of field experiments in the former Wheat and Barley Research Institute of Suwon, Korea from September 1982 to July 1984. When barley was sowed 15 days earlier than or at the locally recommended sowing date (i.e. October 5), it produced more mainstem leaves than the that sowed 15 days later than the local recommendation. The effective tillers (i.e. ear-bearing tillers) were observed in concurrently occurring leaves up to 10/0 (abbreviation of the 10th mainstem leaf) from early and optimum sowed crops, while 9/0 from late sowed crops. Tillering followed the production rule of Gatayama(l952) which has the linear leaf appearance pattern. Early sowing produced more effective tillers, but the highest production of effective ears (i.e. ears heavier than 0.505g) was noticed in sowing at the recommended date. The tillers in the axil of first leaf in mainstem (abbreviated as 1) produced more effective ears than other mainstem tillers (i.e. primary tillers such as C, 2, 3 and 4). The tillers from the axil of first leaf, whether they were primary or secondary, always performed better in the production of effective tillers, grains per ear, grain weight, and grain yield per ear than those from the axil of coleoptile or prophyll. Other tillers from subsequent leaves were also inferior in production with the order of their appearance, thus making first leaf tillers as the best performer(e.g. 1 against C, 2, 3, 4 of primary tillers, 11 and 21 against 1P, 12, 13, 2P, 22 of secondary tillers). Even though the first leaf tiller from the first mainstem leaf(i.e. 11) emerged at a same time with the fourth mainstem leaf tiller(i.e. 4), it was always a better producer of ears and grains. The above observations of hierarchy among tillers were persistent irrespective of cropping conditions and treatments. Sowing at the recommended date produced more effective tillers and grains per ear than early or late sowing. In early and late sowings, more grains per effective ear were observed by early sowing, whereas more grains per ear were produced by late sowing. The order of performance in production of effective tillers and ears per plant was as follows: optimum > early > late sowings. In optimum sowing the mainstems were the highest in grain weight per ear, while the first leaf tillers were the ones in early sowing probably due to winter damage on mainstem ears. Yield contribution by the tillers was greater with the following order irrespective of sowing dates: mainstem, 1, 2, 3, C, 11, 12 and Cl. The contribution of CP, 2P, 21 and 31 varied with sowings.

• Journal of Environmental Science International
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• v.13 no.12
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• pp.1009-1013
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• 2004

The purpose of this study is to select the appropriate wild herbaceous plants on the rooftop. For the purpose of the experiments, 14 wild herbaceous plants were chosen. As the results of the experiments, the wild herbaceous plants growing on the culture soil(perlite) Among the 14 kinds of wild herbaceous plants, such as Chrysanthemum boreale, Taraxacum mongolicum, Aster Koraiensis, Aster yomena, Oenothera odorata, Oenothera lamarckiana, Patrinia scabiosaefolia showed good effects on growth of above ground parts. Therefore, these plants will effective for the rooftop revegetation. Callistephus chinensis and Lotus corniculatus var. Japonicus showed good height growth, wherase covering rate was worst. Chrysanthemum boreale, Platycodon grandiflorum, Patrinia scabiosaefolia were plant height, wherase covering rate was not good . For the expected number of seedings more than 3,000 per square meter, many seedings got withered to death while the survivors were suppressed to grow slow in the early stage due to the densityproblem.

• Magazine of the Korean Society of Agricultural Engineers
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• v.31 no.1
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• pp.71-81
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• 1989

Soil erosion was investigated to find out difference in amount of soil eroded from slope land at early stage of young grasses and at later stage with sufficient cover with different slopes. The six experimental plots were formed on 8$^{\circ}$, 10$^{\circ}$, 15$^{\circ}$, 20$^{\circ}$, and 25$^{\circ}$, with 2m width and 20m length located at the Hwak Kok Ri, Chun Sung Gun, Kang Weon Do. The amount of soil eroded and run-off were collected from 1. May 1987. to 30. October 1988, growing with grasses sowed 2. September 1987. The results were as follows : 1. The amount of soil eroded from the plots except 8$^{\circ}$ plot exceeded the allowable soil erosion with 14 ton/ha during the land formuing before establishment of sufficient surface cover with grasses. Therefore, proper soil conservation practice should be recommeneed. 2. The amount of soil eroded increased exponentially with increased slope as 1.24 times for 15$^{\circ}$1.65 times for 20*, and 2.94 times for 25$^{\circ}$, m comparing with standared 10$^{\circ}$ polt. 3. The erosion occurred mainly by high density of rainfall exceeding lOOmm as consecutive precipitation during the raining peried or accompanied by typhoon passing. 4. The significant soil erosion, when the land covering ratio was over 95% after seeding of grass, was recorded only by the single continuous storms over lOOmm of concentrated precpitation, of which amounts were 1/73~/250 of the allowable soil erosion. 5. The amount of soil erosion from the plots with sufficient surface cover with grasses increased as the slope increased however the amounts were small enough to be neglected. 6. Desolation by soil erosion would be minor problem up to the slope of 20$^{\circ}$ when the mountainous area developed to the grassland with sufficient cover. But it could be concerned on the turn to the hare land by the treading of livestocks with the land slope over 25$^{\circ}$. 7. The run-off of rainfall increased by the increament of slope but it was not exponentially increased. 8. The run-off of rainfall after seeding of grass reduced by 20% in comparison with the run-off of rainfall before seeding, which might be due to infiltration of rainfall promoted by the grass roots.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.103-103
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• 2002

This study was conducted to investigate cryopreservation of pearl oyster, Pinctada fucata martensii larvae. Four cooling rates (-0.25, -0.5, -0.75 and -1.0$^{\circ}C$/min.) were used to examine a proper cooling rate during cryopreservation of trochophores before seeding temperature (-12$^{\circ}C$). Seven developmental stages (early and late trochophores, early and late D-shaped larvae and early, middle and late umbo stage larvae) and different sugars (fructose, glucose and sucrose) were used to investigate optimal larval stage and effective sugar in cryopreservation of larvae. The survival rates of frozen-thawed trochophores increased at cooling rate of -1.0$^{\circ}C$/min. As larval developing, survival rate of frozen-thawed larvae increased, except umbo stage larvae, and especially late D-shaped larvae highly survived as 91%. Addition of sugar revealed positive effect on cryopreservation in this experiment and 0.2 M glucose and sucrose mixed with 2.0 M dimethyl sulfoxide significantly enhanced survival rate of larvae (P<0.05). The results of our study indicate that desirable cooling rate, developmental stages of larvae and effective sugar far cryopreservation of pearl oyster, P. fucata martensii larvae are -1$^{\circ}C$/min, late D-shaped larvae and 0.2 M glucose and sucrose, respectively.