• Journal of Korean Society of Forest Science
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• v.76 no.3
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• pp.230-240
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• 1987

Half-sib seedlings of Ginkgo biloba (one-year-old) were treated with various simulated acid rains(pH2.0, pH3.0, pH4.0 and pH5.0) to examine the effects of acid rain on leaf surface area, leaf injury, leaf chlorophyll content and photosynthetic ability of the leaf tissue. The seedlings were grown in a pot($4500cm^3$) containing one of three different soils(nurseryy soil, mixed soil and sandy soil). Simulated acid rain was made by diluting sulfuric and nitric acid solution($H_2SO_4:HNO_3=3:1$, V/V) with tap water and tap water(pH6.4), and treated by 5mm each time for three minutes during the growing seasons(April to October 1985). Acid rain treatments were done three times per week to potted seedlings by spraying the solutions. The results obtained in this study were as follows : 1. Leaf surface area per seedling at pH2.0 level was the lowest among the levels of pH, but those at other pH levels were not significantly different. 2. Leaf injury(injured leaf rate and injured leaf area) increased with decreasing pH levels of acid rain. 3. Leaf chlorophyll content measured during the period June through October was significantly different among the soil types, and that of the seedling in nursery soil was the highest. The lower pH levels of simulated acid rain was treated ; more leaf chlorophyll content was measured at the beginning of treatment, and the more it severely decreased at the late growing period. 4. Photosyntetic abilities, and the highest value was shown in nursery soil. Significand difference in photosynthetic ability among the levels of pH was observed only in August. Photosynthetic ability increased with decreasing pH levels at the beginning of treatment, but decreased rapidly after July.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.4
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• pp.413-421
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• 2023

Data on salt tolerance, optimal sowing depth, soil bulk density (pb) and cardinal temperatures required for the germination and emergence of perilla (Perilla frutescens (L.) Britt) are scarce for reclaimed land soil. An experiment was conducted across six temperature treatments (10, 15, 20 , 25, 30, and 35℃) to determine the cardinal temperature for perilla seed germination and four salinity levels (0, 20, 40, and 60 mM) to determine the salt tolerance. Another experiment was performed for quantifying the emergence response of perilla to pb (1.1, 1.3, and 1.5 g cm^-3), sowing depth (1, 2, 3, and 4 cm) and soil salinity. The results revealed that increased sodium chloride levels caused a significant reduction in the seed germination at Deulhyang and Sodam. The optimum upper limit temperature was less than 35℃. The optimal sowing depth and soil bulk density were 1 cm and 1.1 g cm^-3 respectively. Perilla seedling growth was inhibited at 1.9 dS m^-1 although varying responses were observed. These results aid our understanding of the germination and emergence rate of these crops and provide data for field cultivation to optimize crop sowing in reclaimed land.

• 한국약용작물학회:학술대회논문집
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• 2007.05a
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• pp.129-130
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• 2007

• The Korean Journal of Ecology
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• v.12 no.1
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• pp.21-35
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• 1989

It was found that seed germination and seedling growth of selected species were inhibited by phytotoxic substance released from black pine. The longer was the aqueous extraction time of black pine needles, the smaller was the relative germination and growth of the species were inhibited in aqueous leachate and rain leachate as well as in soil underneath the black pine trees. In addition, the growth of lettuce was suppressed in volatile substances from black pine needles. To detect phytotoxic substances of black pine needles, paper chromatography and high performance liquid chromatography were used and fourteen kinds of KDICical compounds were isolated and identified as phenolic acids including benzoic acids. The growth of lettuce was inhibited in the experiment using reagents identical to these KDICical substances and a great inhibition was observed in the concentration of less than 5$\times$ M.

• Proceedings of the Korean Society of Crop Science Conference
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• 2001.09a
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• pp.222-223
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• 2001

• 한국약용작물학회:학술대회논문집
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• 2011.09a
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• pp.114-115
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• 2011

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.158-173
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• 1993

The formulated mechanization packages for grain maize production have performed to the expected limit generating encouraging information. Besides physical feasibility , management factors viz ; production operation sequence, operations scheduling and machinery matching with respect to environment can still limit system suitability. A new production operation sequence was introduced to overcome weed problems and limitations of available working days. Proper operations scheduling will improve the initial soil-crop environment for better seedling establishment, and reduce the (). been identified as key factors to reduce capital investment and cost of proudction .

• The Korean Journal of Ecology
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• v.14 no.2
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• pp.121-135
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• 1991

A number of laboratory experimentes have performed to elucidate water-soluble of volatile substances from wormwood plant(artemisia princeps var. orientalis) as growth inhibitor or phytotoxicant. in germination tests with aqueous extracts of leaves, stems and roots of the wormwood plants, most tested species showed that relative germination ratio was inversely proportional to comcentration of the extracats. and seedling elongation and dry weight of the species were heavily inhibited with the extracts, incubated leaves, volatile substances of the leaves and soil underneath wormwood plants. gas Chromatography was employed to find out possible phytotoxic substances or growth inhibitors of wormwood leaves. ten substantes have isolated, and most of them were identified as terpenoids.

• Journal of Plant Biology
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• v.13 no.1
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• pp.1-12
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• 1970

The Nongkwang variety was sown directly in the field by the three methods of dibbling, drill seeding and broad-casting in non-, low- and high-salty areas, and compared with the growth of transplanted rice in each areas. The yield of rough rice was increased remarkably by direct sowing when compared with that produced by transplanting inboth salty areas, but in non-salty area, the former was decreased significantly. There was no significant difference in the yields of rough rice resulting from three seedling methods of direct sowing in each area. The direct sowing method was predominated in number of panicle, weight of panicle, ratio of matured grains, milling recovery percentage, and straw weight in both salty areas, and dicreased in panicle weight and ratio of matured grain in nonsalty area.

• Korean Journal of Organic Agriculture
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• v.5 no.2
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• pp.125-140
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• 1997

This experiment was carried out to investigate the effects of compost mixed with microorganism compost fermented for the production of high quality plug seedlings of tomato and red pepper. The results are summarized as follows. As a result of compost analysis, EC value was increased with increment of microorganism compost supplemented but lowered gradually in the late period of seedlings growth, pH value of microorganism compost fermented was 9.3 which is strong alkalinity. In the plot of 30 percent of microorganism compost fermented early growth of tomato seedlings was better in terms of plant height, leaf area and total dry weight. However, early growth of red pepper seedlings was shown in the plot of supplemented with 20 percent of microorganism compost fermented. The higher the mixing rate over 60 percent of micrroganism compost fermented to the soil used retarded the seedlings growth regardless of tomato and red pepper.