• 아시안잔디학회지
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• 제15권2호
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• pp.77-86
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• 2001

The experiments were carried out to investigate effect of shading rare on variegata appearance and leaf growth of variegated liriope (Liriope platyphylla Wang et Tang variegata Hort.) The plant was grown under four different light intensities such as 0(natural light intensity), 25, 50 and 75% shading conditions. Leaf variegata appearance was better in the light than in the shade. Leaf showed good growth at 0, 25% shading treatment, average leaf width and area of yellow part were highest at 0% shading treatment. As increased shading rate, number of stomate per unit area decreased. Total chlorophyll of the whole leaf and green part were reduced by increasing shading rate, while yellow part showed oppositely. In the epidermis, cell size of 75% shading treatment showed larger than those of 0% shading treatment.

• 아시안잔디학회지
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• 제5권2호
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• pp.95-114
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• 1991

This paper was designed to estimate the interaction of the first productivity, light conditions and to analyze the ecophysiological productivity, growth characteristics grown under various shading conditions in Zoysia japonica . The results summarized this experiment were as follows; 1.After transplanting the grass, increasing rate of leaf number and total leaf length was remarkahly high at the early growth stage in the control and the 30% shading plot. 2.The increasing rate of leaf area ratio (LA R) in all the experimental plot was remarkable high at the early growth stage after transplanting the grass. Especially, the control and 30% shading plot in compared with another plots, were remarkably high at rate of leaf area. 3.The length and the node number of rhizome in the control and 30% shading plot were also high and the difference was significantly large by the growth stage. 4.Chlorophyll content was very high at 36days after transplanting and then decreased. Increasing rate of shade resulted in its low content. The rate of chlorophyll a to b was decreased by in-creasing rate of shade. 5.The content of soluble sugar in the control and 30% shading plot was low at the early growth after transplanting and high at the late growth stage. Its content in the plot of 70% shading was remarkably low throughout the growth stage. 6.The increasing rate of standing plant in all the experimental plots was high at the early growth stage after transplanting. Increasing rate of shade was typically low through all the growth stage.

• Journal of Ecology and Environment
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• 제29권5호
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• pp.461-467
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• 2006

The growth pattern and the seasonal changes in nutrient contents of Humulus japonicus were investigated. Stem length of H. japonicus reached the maximum from 240 to 260 Julian date and the median value was found at 255 Julian date. The maximum leaf area was observed from 235 to 248 Julian date and the median value was at 240 Julian date. The maximum growth rate of the stem length ranged from 205 to 227 Julian date. The leaf area showed the maximum growth rate from 196 to 214 Julian date. The median date in the growth rate of the stem length and leaf area was 212 and 205 Julian date, respectively. The growth rate of H. japonicus was related to rainy season and precipitation. Phosphorus and sodium contents of H. japonicus were correlated with maximum potential rate of relative growth. Although stem biomass of H. japonicus was $ 1.5{\sim}3.5$ times larger than that of leaf, N content of the leaf ($4.48{\sim}5.27%$) was about 2 times higher than that of the stem ($2.00{\sim}3.62%$). High content of N might be responsible for the high growth rate of H. japonicus in summer. This result provides valuable information for appropriate timing for the removal of H. japonicus.

• 한국초지조사료학회지
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• 제8권2호
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• pp.104-109
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• 1988

A field experiment was conducted in order to investigate the seasonal changes of leaf grwoth and related characteristics in three cultivars of orchardgrass; Potomac, Kay and Sumas. The results were summarized as follows: 1. Leaf elongation was increased in a nearly linear phase during first and third cutting stages. It was increased slowly in early 10 days to 15 days after cutting and increased rapidly there-after during the rest cutting stages. In cultivars, Potomac was showed higher leaf elongation than other cultivars during all cutting stages. There was no difference of leaf width within cutting stages, but the leaf width of fall regrwoth was narrow. Sumas had relatively short and wide leaves. 2. Leaf dry weight and leaf area in first cutting stage were larger than others. Leaf area was increased rapidly form 15 days after cutting and leaf weight was increased rapidly from 20 days over all cutting stages. The increase in leaf area and dry weight were slow down after 30 days. 3. Number of epidermal cells was increased rapidly after cutting and the rate of increase was slow down after 30 days. In a cross section of leaf tissue, the part of mesophyll was occupied with about 60% of total area and larger area than other tissue, the part of mesophyll was occupied with about 60% of total area and larger area than other tissues. Leaf tissue had a large vacancy at early growth period after harvest and was filled gradually with mesophyll. This result was related to the increase of leaf dry matter.

• 아시안잔디학회지
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• 제26권1호
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• pp.1-7
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• 2012

본 연구는 국내 잔디 주 생산 단지인 전라남도 장성군 지역에 재배되고 있는 한국잔디의 형태적 다양성 평가 및 상기 지역에서 수집된 잔디의 생육속도 등 이용성을 평가해 보고자 수행되었다. 총 101개 개체를 수집하였다. 수집개체를 온실에 포트 상태로 생육시킨 후 형태적 특성을 조사하였다. 형태적 특성으로는 엽폭, 초장, 잎각도, 잎집 길이, 털 유무, 포복경 길이, 엽색 등의 변이를 비교하였으며, 특이성 개체 7개를 선발하였다. 생육속도를 조사하기 위해 한국잔디 기존 대조품종 8개와 국내 주 생산단지에서 수집된 계통 7개 그리고 육종계통 3개를 비교하였다. 장성징역 수집 잔디 101개체의 평균 엽폭은 3.4 mm로 나타났으며, 잎각도는 45.8도, 초장은 21.6 cm, 최하위 엽의 높이는 5.0 cm 그리고 엽장은 14.1 cm의 특성을 보였다. 피복속도 조사결과 CY6097, CY6069 등이 스프리그 식재 5개월 후 각각 70%, 68.3%의 피복률을 나타내었다. 가장 느린 생육속도를 보인 금잔디의 31.7% 대비 약 2배 빠른 피복속도였다. CY6069의 경우는 피복속도가 안양중지 60.0% 보다 빠르면서도 마디간 길이가 5.1 cm로 짧게 나타나 고품질 계통으로 가치가 있는 것으로 나타났다. 상기 특성 평가를 통해 잔디재배 주 생산단지인 장성 지역에서 생육속도가 빠르며, 고품질의 계통의 대표종을 선발할 수 있었다.

• The Korean Journal of Ecology
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• 제21권4호
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• pp.329-335
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• 1998

The growth of Phytolacca L. grown under three light regimes at three nutrient concentrations was analyzed. The effect of shading treatment on plnat growth was greater than that of nutrient treatment. Plant dry mass increased more than 5-fold during 21 days under 33% and 100% irradiances, whereas that was strongly reduced under 8% irradiance. Net assimilation rate decreased with plant growth irrespective of light and nutrient treatments, though the highest net assimilation rate was shown under 100% irradiance. Under 33% irradiance leaf area in plants supplied with nutrient solution increased to such extent as to compensate reduction in net assimilation rate, whic maintains almost identical growth rate with that under 100% irradiance. The relatonship between total plant nitrogen and leaf nitrogen content was dependent on the growth irradiance. Moreover, leaf nitrogen and specific leaf weight were also changed depending on the light and nutrient conditions. Based on these findings, it is suggested that the adaptive characteristics of Pokeberry plant to light and nutrient conditions may contribute to rapid extension of Pokeberry habital in Korea rocently.

• 한국연초학회지
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• 제4권2호
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• pp.41-50
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• 1982

To investigate tile effects of growth characteristics on the yield, price per Kg, chemical contents and physical properties in Burley tobacco, ten varieties including Burley 21 were tested in this study. The results obtained are summarized as follows. 1 Forty to fifty days after transplanting, CCR (Crop Growth Rate) was the highest. RCR (Relative Growth Rate) increased up to 40 days, but decreased 50 days when maturation began. High- yielding varieties showed high CCR and RCR till 60 days. 2. Total alkaloid content of cured leaf increased about three times than that of topping stage, but the increased rates were some what different among varieties. 3. Leaf area, stalk diameter, stalk height and days to flower showed positive correlations to yield, whereas leaf thickness and weight per unit leaf area showed negative. 4 Varieties which are high in cured leaf weight ratio and weight per unit leaf thickeners showed relatively poor quality. 5 Nitrogen content was high in leafy and larger stalk diameter variety. 6. There are positive correlation between weight per unit leaf thickness and filling power. The time of combustion was positively correlated to leaf thickness and weight Per unit leaf. 7. It can be concluded that many characteristics are related to the yield, but not quality. It is, there fore, easy to Predict tile yield, but difficult to forecast the qualiffy.

• Weed & Turfgrass Science
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• 제6권1호
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• pp.55-60
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• 2017

Shade affects turf quality by reducing light for photosynthesis. The shade tolerance of the tropical grasses, Digitaria longiflora and Axonopus compressus were evaluated against Stenotaphrum secundatum (St. Augustinegrass). The grasses were established under shade structures that provide 0%, 50%, 75% or 90% shade level for 30 days. A suite of leaf traits, recorded from similar leaf developmental stage, displayed distinct responses to shade conditions. Leaf length, relative to control, increased in all three species as shade level increased. The mean leaf extension rate was lowest in St. Augustinegrass (80.42%) followed by A. compressus (84.62%) and D. longiflora (90.78%). The higher leaf extension rate in D. longiflora implied its poor shade tolerance. Specific leaf area (SLA) increased in all species with highest mean SLA increase in D. longiflora ($348.55cm^2mg^{-1}$)followed by A. compressus ($286.88cm^2mg^{-1}$) and St. Augustinegrass ($276.28cm^2mg^{-1}$). The highest SLA increase in D. longiflora suggested its lowest performance under shade. The percent green cover, as estimated by digital image analysis, was lowest in D. longiflora (53%) under 90% shade level compared to both species. The relative shade tolerance of the three turfgrasses could be ranked as St. Augustinegrass > A. compressus > D. longiflora.

• 식물병연구
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• 제13권1호
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• pp.20-23
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• 2007

2002년부터 2005년까지 4년간 벼 흰잎마름병 초발병 조사결과 2002년보다 초발병일이 20$\sim$30일 이상 빨라지고 있음을 확인하였다. 벼 흰잎마름병 발병시기 및 병반면적율에 따라 수량이 감소하였는데 병반면적률이 10% 이하에서는 피해가 적었으나, 병반적율이 증가함에 따라서 수량감소가 점점 많아졌고, 25% 이상일 때부터 수량감소 및 현미천립중 등에서 현저히 낮아지고 병반면적율이 50% 이상이고 유수형성기 발병시 수량 29%, 현미천립중 2.3g, 현미완전립률 18%까지 감소되었다. 밥맛의 기준이 되는 식미치인 점도에서도 병반면적율이 증가함에 따라 낮은 식미치를 보였다.

• 한국자동차공학회논문집
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• 제4권6호
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• pp.229-235
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• 1996

The tapered leaf spring is regarded as the adequate tool to improve ride quality and to reduce vehicle weight of commercial vehicles. These effects are due to minimizing the contact area of each leaf by reducing the number of leaves and by optimizing the thickness profile of each leaf. But in adapting the tapered leaf spring to improve ride quality, we often have some problems of bad pitching and bouncing motion. This paper shows the basic properties of tapered leaf spring by rig tests and how to improve ride quality of a vehicle with tapered leaf springs, compared with multi-leaf spring. From the results of vehicle tests and rig tests it is concluded that the ride quality was effected by the dynamic spring rate and the friction of the tapered leaf spring.