• Korean Journal of Environment and Ecology
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• v.6 no.1
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• pp.1-8
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• 1992

Artificial acid rain (pH 3.0, 4.0 and 5.0) was treated on the seeded pots of 4 species to examine its effects on germination, leaf injury and seedling growth. Artificial acid rain was prepared by diluting sulfuric acid with ground water and ground water (pH 6.5) was used as control. Artificial acid rain was sprayed to seeded pots three times per week. About 5mm of artificial acid rain was treated each time from early April to early October, 1991. Germination, seedling establishment, leaf injury, soil acidity and seedling growth were measured and compared among the treatments. The results were summarized as follows; 1. Germination and seedling establishment rate of Pinus thunbergiana was highest on the pH 4.0 pot whereas that of Picea abies was highest on the pH 3.0 pot. Those of Pinus densiflora and Abies holophylla were not significantly differed among the treatments. 2. The differences in seedling height of all species were not significantly differed among the treatments. 3. Seedling dry weight of Pinus densiflora differed significantly among the treatments. but that of Pinus thunbergiana did not differ. 4. With decrease of pH value of artificial acid rain. the number of injured needle and injured individual tended to be increased. 5. The differences of soil acidity were significant among the treatments for all species.

• Proceedings of the Korean Society of Crop Science Conference
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• 1989.10a
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• pp.18-19
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• 1989

• Proceedings of the Korean Society of Crop Science Conference
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• 1990.05a
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• pp.24-25
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• 1990

• Proceedings of the Korean Society of Crop Science Conference
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• 1990.05a
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• pp.26-27
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• 1990

• Journal of Forest and Environmental Science
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• v.17 no.1
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• pp.1-17
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• 2001

Forming a part of "Cooperative Practical Study for the Modernization of the Management of National Forest", this study was conducted to provide overall ecological information for the natural regeneration of major tree species on the basis of community structural attributes in the deciduous forest ecosystem. Followings are summarized characteristics of the natural regeneration for the selected tree species. Betula costata : Although large number of seeds are dispersed by wind, they require mineral soils to germinate. Thick litter layer could be an obstacle to germinate. After germination, the seedling requires large amount of light for successful establishment. Acer mono : Characterized by high shade tolerance and weak drought resistance, the seedling should be overcasted with more than 50% of canopy coverage. High stand density should be maintained to produce good quality of timber. The potential of coppice may be high. Ulmus laciniata : Since this species needs high rate of troll moisture and light, around 60% of canopy coverage should be maintained to retain moisture and incoming light. The competition with other vegetation should be removed for the favor of successful seedling establishment. Fraxinus mandshurica : This species requires moist mineral soils to germinate. After germination, the seedling needs large amount of light and moisture for successful establishment. Site preparation should be applied to reduce competition with weedy vegetation. Fraxinus rhynchophylla : Interval of large seed crops may be highly varied. Thick litter layer could be an obstacle to germinate. Site preparation should be applied to reduce competition with weedy vegetation so as to achieve successful seedling establishment. Quercus mongolica : Including the difficulty of seed supply by the consumption, thick litter layer and mountain bamboo cover could be the obstacle to germinate. More than 50% of relative light intensity is necessary to achieve successful seedling establishment. Kalopanax pictus : Thick litter layer could be an obstacle to germinate. The seedling needs large amount of light and moisture for successful establishment. Abies holophylla : In spite of high shade tolerance, the growth rate in sapling stage may be extremely slow. Cornus controversa : Seeds (drups) are consumed and dispersed by animals, tending to be not sufficient in seed supply. This species requires large amount of light for successful germination and seedling establishment. Tilia amurensis : The difficulty of seed supply might be expected with low seed purity and double dormancy. Since thick litter layer could be an obstacle to germinate, the species requires moist mineral soils for successful germination. The potential of coppice may be extremely high.

• Journal of Practical Agriculture & Fisheries Research
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• v.18 no.1
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• pp.93-100
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• 2016

This research was conducted to determine a pre-germinated herbicides with iron-coated seeds in water and wet hill seeded rice. Days of rice seedling emergence was the faster germination at the application of benzobicyclon > oxadiazon > thiobencarb > butachlor and the sealed iron-coated seeds with pre-germinated seeds> pre-germinated seeds> iron-coated seeds with pre-soaking. The seedling establishment was relatively high in untreated control and benzobicyclon among seed treatments by 63.7% and 75.7%. There was 100% seeds killed of pre-germinated seeds in terms of herbicide phytotoxicity and sealed iron-coated seeds with pre-germinated seeds in butachlor but benzobicyclon was of safe with 2% rice seeds killed. Infant rice seedling height was of 9.2-12.9cm in benzobicyclon and 11.9-16.3cm in untreated control and thus there was relatively normal development and growth at the initial rice seedling.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.2
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• pp.95-100
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• 1998

Seedling establishment of soybean [Glycine mar (L.) Mer-rill] is an important factor for soybean production in the field. The objective of this study was to determine the distribution of chemical composition in the emerging organs during seedling development in soybeans. Three soybean cultivars (Hill, Paldalkong, and Jangyeobkong) were planted at the Research Farm of College of Natural Resources, Korea University, on May 26, June 5, and June 14. Protein, oil, sugar, and starch contents were measured in each organ at each developing stage. Mean dry weight of three soybean cultivars decreased until VE stage and increased after this stage. Protein content of whole seedling did not change significantly during the seedling growth stage, but the amount in cotyledons markedly decreased with each growth stage increment. About 88% of the cotyledon protein was translocated to the other parts of the seedling at the V2 stage. Oil content of cotyledons sharply decreased until the V1 stage. Sugar content of the seedling was not detected at VE stage and starch content of seedlings increased slightly at VE and VC stages. For the changes of each metabolic component, the amount for whole plants decreased until the V1 stage and started to increase after this stage. The results of this study provide evidence for the breakdown of carbohydrates and oil at the initial stage of seedling growth.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.4
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• pp.320-327
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• 1990

Experiments were conducted to investigate the method to raise seedling establishment rate and the optimum seeding dates and rates in direct seeding culture using transplanter under submerged field condition in Chuncheon area during 1986 to 1988. Direct seeding on submerged field using transplanting machine after sowing on seedling growing box contained with paddy or upland soil was possible. Higher rate of seedling establishment was obtained in case of sowing sprouted seed and intermittent irrigation after sowing. Seedling establishment rate was higher both in April 30 or May 10 seeding plot. Minimum daily average air and soil temperature to ensure more than 70 percent seedling establishment was 14.8$^{\circ}C$ and 16.3$^{\circ}C$ respectively. Optimum sowing date in the direct sowing was early May and optimum sowing rate was 200g per box, 6kg per l0a. In this case rice grain yield was 481kg per l0a and this is almost same yield level compared hand and machine transplanting.

• 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.

• Journal of The Korean Society of Grassland and Forage Science
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• v.10 no.2
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• pp.65-69
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• 1990

An experiment was carried out ot determine the effects of seeding rates and seedbed preparations on the establishment and yield of surface-sown pasture species. Establishment of orchardgrass was significantly increased by the lowest seeding rate of 20 kg/ha as compared to 30 and 40 kg/ha, but no differences were found between the seeding rates of ladino clover. Both raking and burning significantly improved the establishment of pasture species in comparison with non-treatment. There was a significant difference between the raking and burning for the establishment of orchardgrass, but no significant difference was found between the two treatments for that of ladino clover. Increasing seeding rate of pasture species did not enhance the yield of surface-sown pasture, but both the raking and non-treatment significantly increased the yield of pasture species. The results suggest that both the raking and burning can improve the establishment but increasing seeding rate over 20 kg/ha and burning may not increase the yield.