• Journal of The Korean Society of Grassland and Forage Science
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• v.10 no.3
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• pp.147-151
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• 1990

The purpose of this study is to clarify the relation of survival rates of seedling plants under grown orchardgrass populations and control by the difference cutting frequency. The orchardgrass populations investigated in this study have passed for 10 years after establishment. Cutting frequencies were 3, 4 and 5 times in a year. This experiment was conducted from April to October, 1989 at the experimental field of Institute of Agricultural Development, Yonsei University. The results are summarized as follows: 1. The survival rates of seedling plants decreased by the days after sowing. The final survival rates of seedling plants were 7.8%, 38.9% and 33.8% in 3, 4 and 5 cuttings, respectively. 2. Relative light intensity indicated highly possitive correlation with relative survival rates of seedling plants and negative correlation with plant length of orchardgrass populations in 4 and 5 cuttings. 3. The frequency distribution of survival seedling plants at 177 days after sowing were showed high values in seeding spots near the adjacent plants of 3 cutings, but in the middle of seeding spots between adjacent plants of 4 .and 5 cuttings, respectively. 4. The plant length of seedling became longer towards the seeding spots near the adjacent plants but the number of tillers increased slightly up to the middle of seeding spots between adjacent plants in all cutting frequencies.

• Korean Journal of Plant Resources
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• v.27 no.2
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• pp.174-182
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• 2014

This study was carried out to investigated the effects of soil type and light condition on seedling quality of rare and endemic plants Orostachys iwarenge and Orostachys iwarenge for. magnus. The best seedling quality of O. iwarenge and O. iwarenge for. magnus seedling were shown in Klasmann soil at non-shading or LED (Red+Blue) condition, 50% shading or LED (Red+Blue) condition, respectively. Survival of O. iwarenge seedling was not influenced by the period of experiment but survival of O. iwarenge for. magnus seedling in sandy soil conditions decreased significantly. Results of correlation analysis of seedling quality and survival rate, indicated that O. iwarenge showed a correlation of 0.8 or more at plant height, leaf length and fresh weight. O. iwarenge for. magnus showed a correlation of 0.8 or more at plant height, leaf width and leaf length. Especially, seedling survival of O. iwarenge and O. iwarenge for. magnus showed a correlation of 0.8 or more at first seedling survival and second seedling survival. It was important to manage the early seedling stages of O. iwarenge and O. iwarenge for. magnus. Therefore, seedlings with plant height (over 2.5~4 cm) and root length (over 3~5 cm) were grown vigorously at 35 days after the seedling was transplanted in mid-April in Klasmann soil of 72 plug cell tray at LED (Red+Blue) conditions.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.2
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• pp.21-32
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• 2011

The effects of high polymer on the seedling survival were investigated in three major turfgrasses. Twelve treatments were used in the study with different rates of sand, soil organic amendment (SOA), and water-swelling polymer (WSP). Turfgrass seedling survival rate was evaluated in creeping bentgrass (CB), Kentucky bluegrass (KB), and zoysiagrass (Zoy) grown under greenhouse conditions. Significant differences were observed among the treatments. Seedling survival rates were variable in CB, KB, and Zoy according to mixing rates of SOA and WSP, being maximum 20.2% in differences. At 6 weeks after seeding, the survival rates ranged from 0.6 to 61.9% in CB, 4.2 to 75.3% in KB and 1.7 to 82.1% in Zoy. A pattern of seedling emergence varied with time among treatments influenced by WSP rates. A proper mixing rate of WSP is considered to be 5% for CB and 5 to 10% for KB and Zoy. In general, overall effect of WSP on seedling survival was clearly observed in the mixtures of sand 80% and SOA 20% in CB. The best result, however, was found from the mixture of sand 85% and SOA 15% in both KB and Zoy. When mixing sand with WSP, a proper rate of SOA is considered to be 20% for CB and 15 to 20% for KB, while 10 to 15% for Zoy. A further research is needed to investigate the effects of WSP on the turf quality in mixtures of sand, SOA, and WSP before a field application.

• Korean Journal of Environment and Ecology
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• v.15 no.3
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• pp.207-212
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• 2001

To seek for restoration method of Abies koreana forest with planting seedlings, Abies koreana seedlings(2, 3 and 5 year old) were planted by date(spring and summer) and surface treatment (coir-mat, coir-net and control) at Janggumok area in Hallasan. Survival rate and shoot growth of the seedlings were measured and compared by planting date, seedling age and surface treatments. For summer planting, survival rates of the seedlings are increased with increasing seedling ages, and those are not differed between surface treatments. For spring planting, survival rates of the seedlings are increased with decreasing seedling ages, and those are not differed between surface treatments. For summer planting, shoot growth of the seedlings are significantly differed between surface treatments. Shoot growth of the seedlings was the highest value 2.11mm at coir-matted plot, and the lowest value 1.49mm at control B)lot. Shoot growth of the seedlings are not differed between the seedling ages, but the highest shoot growth was 2.26mm at coir-matted and 3-year old plot. For spring planting, survival rates and shoot growth of the seedlings are not differed between seedling ages and surface treatments.

• Journal of agriculture & life science
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• v.46 no.2
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• pp.63-73
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• 2012

This study was conducted to investigate effects of fertilization treatments (non-fertilizing, deep-fertilizing 20g, 50g, 100g, and surface-fertilizing 20g) on survival rate, growth performances, and seedling quality index (SQI) of container seedling and bare root seedling of Pinus densiflora in the field. There were no significantly differences in survival rate among fertilization treatments in the field. Besides, there was no toxic effect on seedling by over 100g fertilization in deep-fertilizing treatment. The root collar diameter and height of P. densiflora in both seedling types were the highest at 100g fertilization in deep-fertilizing treatments, and the biomass products and SQI were the same as above growth of root collar diameter and height. In most of the treatments, container seedlings showed better growth performances than bare root seedlings. In optimal fertilization, effect of fertilization was higher in container seedling than bare root seedling.

• 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.31 no.1
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• pp.112-119
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• 1986

The variations of antibiosis to whitebacked planthopper (Sogatella furcifera Horvath) in resistant varieties, N 22 (Wbph 1) and ARC 10239 (Wbph 2) was investigated at different seedling ages and different tillers within a plant. The antibiosis of the rice plants to the insect was measured as the nymphal survival rate on the rice plants. The survival rate of the WBPH on N 22 was greater than on ARC 10239. It was also different at different seedling ages and the tillers within a plant with different tendency of two resistant rice genotypes, N 22 and ARC 10239. NO significant differences of nymphal survival rate was found between 7 and 30 days old seedlings on N 22, and greatly reduced on the 60 days old seedling. On the other hand it was increased up to on 30 days old seedlings and gradually decreased from on 40 days old seedlings of ARC 10239. The nymphal survival rate was greater in tillers than in the main culm of the rice plants.

• Korean Journal of Plant Resources
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• v.26 no.6
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• pp.709-717
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• 2013

The objective of this study was to examine the effect of root pruning intensity in combination with different initial seedling size on the growth of transplanting seedlings of Quercus acutissima. One-year-old seedlings were divided into three groups depending on their height, i.e. small (< 15 cm), medium (25-35 cm) and large size (35 cm <). Root of seedlings was pruned by three intensity such as, leaving 5 cm (severe), 10 cm (medium) and 15 cm (light) of taproot from the root-collar. After one year, we investigated survival rate, height and root-collar diameter (RCD) increment and final shoot dry weight. Also we measured characteristics of newly developed lateral roots such as number, total length, dry weight and diameter. Severe root pruning showed the lowest survival rate in all seedling size. Height increment, RCD increment and shoot dry weight were decreased with increasing intensity of root pruning. Seedlings of medium and light root pruning showed similar above-ground growth and dry weight of lateral roots. More large seedlings showed good survival rate, height increment and final shoot dry mass in all root pruning intensity. Therefore, one-year-old seedlings of Q. acutissima should be pruned taproot by 10 cm and transplanted to obtain excellent performance and increase the efficiency of transplanting work. Based on the findings of this study, it is important that applying to different root pruning intensity depending on initial seedling size for producing 2-year-old seedlings with excellent growth and high quality.

• Journal of Korean Society of Forest Science
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• v.99 no.3
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• pp.359-367
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• 2010

The objective of this study was to find optimal planting season of the effect of vegetation competition around planting tree. This study evaluates the possibility of extending the planting period of containerized seedling of Pinus densiflora (1-0 year). We planted seedling at three different seasons (spring, summer, fall) at 18 plots in 3 locations. Planting sites were composed of vigorous vegetation (Site A) and less vigorous vegetation (Site B). For over 3 years, the study investigated survival rate, growth of root collar diameter and height, and biomass of containerized seedling of P. densiflora. In all sites, containerized seedling of P. densiflora showed high survival rate in summer planting. Height and root collar diameter of containerized seedling of P. densiflora were the highest in summer planting, but in the initial period after planting growth was not good. After time passed, growth rate was increased. Site B showed better growth than Site A. Biomass was the highest in summer planting and also the highest in Site B. These results suggest that planting period can be extended by using containerized seedling and vegetation control in the initial is very important for survival and growth of containerized seedling.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.3
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• pp.79-95
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• 2015

To suggest ecological management plans for invasion of Salix gracilistyla, stepwise environmental sieve of seed dispersal, germination, seedling and juvenile stages were investigated. About 84% of total seeds were released between May 6 and 10. Germination rates significantly declined with decrease of light intensity from 100% to 30% and 0% (p<.001), but above 60% of seeds germinated in all treatments. Difference of germination rates with 0 and 2cm water level was not significant (p = .571). With increase of elapsed time after seed dispersal, germination rates significantly decreased (p<.001), and seed viability was lost within 16 days. Considering both germination rate of seed and survival rate of seedling, survival rate of all dispersed seeds was only 5% when 8 days passed after seed dispersal. All 22-day-old seedlings (height: 1cm) died under flooding of twice level as its height. With decrease of light intensity from 100% to 30%, survival rates of seedling decreased from 90% to 33% (p<.001). In the case of 45-day-old juvenile (height: 20cm), survival rate was 70% under the water level same as its height. There was significant interactive effect of water level and light intensity on the growth of juvenile (height: p<.001, dry weight: p<.01), and survival rate of juvenile was 10% under +20cm-water level and 30%-light intensity condition. The following management plans for invasion of S. gracilistyla are recommended from these results. (1) Dry condition should be maintained at fringe of wetlands for about two weeks at seed dispersal and germination stage (early May~mid May). (2) Water level should be raised to about 5cm at fringe of wetlands for about two weeks at seedling stage (mid May~early June). (3) Water level should be raised to over 20cm at fringe of wetlands for a long time at juvenile stage. Planting trees for shading can raise management effectiveness (mid June~). (4) As water level manipulating is performed as fast as possible for controlling seedling and juvenile, management become easier and more effective.