• Journal of Plant Biotechnology
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• 제35권2호
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• pp.127-132
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• 2008

In bioreactor cultures of plants, inoculum density is an important factor affecting growth and proliferation of the plantlets. To maximize shoot growth and proliferation of grape rootstock '5BB' in bioreactors, inoculum density varied at 15, 30, 45 and 60 single nodes in a 3-liter scale balloon type bioreactor, respectively and cultured for 40 days. Results suggested that the growth and the photosynthesis of the plantlet were greatly affected by inoculum density in the bioreactor. The inoculum density of 45 nodes resulted in the greatest growth (910.4 mg/shoot FW, 764.4 mg/root FW) followed by 30 nodes. $CO_2$ assimilation rate, stomatal conductance, transpiration rate of the plantlet were also highest at the inoculum density of 45 nodes. Significant reduces in shoot and root growth (426.5 mg/shoot FW, 248.4 mg/root FW) were observed at the inoculum density of 60 nodes. When the inoculum density decreased by 15 nodes, plantlets were malformed due to hyperhydricity, resulting in the highest transpiration rate and the lowest $CO_2$ assimilation rate. The plantlets stressed by the inoculum density at 15 nodes and 60 nodes showed larger number and irregular shape of stomata compared to the plantlets inoculated with 45 nodes.

• 한국토양비료학회지
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• 제49권5호
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• pp.548-554
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• 2016

Optimal range of soil physical quality to enhance crop productivity or to improve environmental health is still in dispute for the upland soil. We hypothesized that the optimal range might be established by comparing soil physical parameters and their interactions inhibiting crop growth. The parameter identifying optimal range covered favorable conditions of aeration, permeability and root extension. To establish soil physical standard two experiments were conducted as follows; 1) investigating interactions of bulk density and aeration porosity in the laboratory test and 2) determining effects of soil compaction and deep & conventional tillage on physical properties and crop growth in the field test. The crops were Perilla frutescens, Zea mays L., Solanum tuberosum L. and Secale cereael. The saturated hydraulic conductivity, bulk density from the root depth, root growth and stem length were obtained. Higher bulk density showed lower aeration porosity and hydraulic conductivity, and finer texture had lower threshold bulk density at 10% aeration bulk density. Reduced crop growth by subsoil compaction was higher in silt clay loam compared to other textures. Loam soil had better physical improvement in deep rotary tillage plot. Combined with results of the present studies, the soil physical quality was possibly assessed by bulk density index. Threshold subsoil bulk density as the upper value were $1.55Mg\;m^{-3}$ in sandy loam, $1.50Mg\;m^{-3}$ in loam and $1.45Mg\;m^{-3}$ in silty clay loam for optimal soil physical quality in upland.

• 한국약용작물학회지
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• 제21권5호
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• pp.372-379
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• 2013

The present study was investigated the effect of planting density on plant growth and yield of Panax ginseng C. A. Meyer. Sowing density is one of the most important factors affecting yield. The value of roots have affected by shape, color, weight and degree of disease injury in ginseng. Also, it needed to minimize elapsed time for 5 years including pre-planting field management and cultivation period. We were conducted to evaluate that planting densities and varieties on the growth, yield and missing rate. The direct sowing was treated seeds density as a four levels (seeds; 72, 90, 120, 144) and 10 different varieties with 3 years old ginseng roots. Root weight was significantly affected by planting density and variety, but the number of lateral root and yield were affected by only planting density. Growth index was related to variety and planting density. Also, Root shape index was affected by both varieties and planting densities. Suitable planting density and variety were 120 plant per 1.62 $m^2$ and Gopoong, respectively. Results showed that it was also a significant difference (p=5%) in variety of planting density on growth.

• Journal of Ecology and Environment
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• 제37권4호
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• pp.177-184
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• 2014

This study was conducted to develop allometric equations and to determine the stem density and biomass expansion factor (BEF) for the estimation of the aboveground and belowground biomass of Cryptomeria japonica in Jeju Island, Korea. A total of 18 trees were harvested from the 40-year-old C. japonica stands in Hannam experimental forest, Jeju Island. The mean biomass of the C. japonica was $50.4Mg\;ha^{-1}$ in stem wood, $23.1Mg\;ha^{-1}$ in root, $9.6Mg\;ha^{-1}$ in branch, $4.6Mg\;ha^{-1}$ in needle and $4.3Mg\;ha^{-1}$ in stem bark. The diameter at breast height (DBH) was selected as independent variable for the development of allometric equations. To evaluate the performance of these equations, coefficient of determination ($R^2$) and root mean square error (RMSE) were used and results of the evaluation showed that $R^2$ ranged from 71% (root biomass equation) to 96% (aboveground biomass equation) and the RMSE ranged from 0.10 (aboveground biomass equation) to 0.33 (root biomass equation). The mean stem density of C. japonica was $0.37g\;cm^{-3}$ and the mean aboveground BEF was $1.28g\;g^{-1}$. Furthermore, the ratio of the root biomass to aboveground biomass was 0.32.

• 한국작물학회지
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• 제46권5호
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• pp.407-410
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• 2001

This study was conducted to determine the optimal planting distance in cultivation of yacon (Polymnia sonchifolia Poeppig ＆ Endlicher). Plug seedlings were planted with 6 different plant densities of 80 $\times$ 60, 80 $\times$ 50, 70 $\times$ 50, 70 $\times$ 45, 70 $\times$ 40 and 60 $\times$ 45 cm. The plant height and the petiole length were increased with increasing the planting distance. The tallest plant height of yacon was 165.4cm with the plant density of 80 $\times$ 60 cm. However, branch number per plant, leaf number on main stem and stem diameter were not significantly difference among planting densities. Tuberous root was harvested 31.42 tons/ha in 70 $\times$ 50 cm spacing. The ratio of heavier tuberous roots than 200 g to total tuberous roots decreased significantly according to increase of planting density. Fresh weights of shoot and root, contain the crown bud, were decreased, as planting distance was shorter. Tuberous root number was fewer but its weight was heavier in wide planting than in dense planting. We think that optimal planting density is about 30,000 plants/ha, if it were to be 70 cm row spacing, intrarow spacing should calculate about 47cm.

• 한국약용작물학회지
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• 제18권2호
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• pp.93-97
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• 2010

Cultural practices of Asparagus cochinchinensis in highland area were performed for a potential medicinal crop. These studies were examined to propagation methods, planting densities, nitrogen treatments, and cropping years. The results are summarized as follows. The adequate number of buds per tuberous root was 4 for vegetative propagation because the number of tuberous root harvested was 16.8 and the yield was also the highest, exhibiting 1,060 kg/10a. The suitable planting time for vegetative propagation was later than early April. If the earlier tuberous roots were planted, the less they emerged. The highest emergence rate was obtained from the planting density of $30{\times}20cm$ as 97.2% while the yield was highest in the $30{\times}15cm$ density, exhibiting 1,883 kg/10a with emergence rate at 94.9. It seemed that the higher planting density promoted plant height growth and yield in Asparagus cochinchinensis. The highest fresh weight was recorded at 6 kg/10a of nitrogen fertilizer into the sandy loam soil compared to the level of 0, 3, 9 kg/10a. The yield was increased with cropping years. However, the proper harvesting time was the second year of cultivation because the rate of weight increase was maximized in the 2-year-old tuberous root. The yield in the third year was decreased as compared to that of the second year.

• 한국토양비료학회지
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• 제16권2호
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• pp.126-130
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• 1983

토양의 물리적(物理的) 특성(特性)이 작물(作物)의 뿌리 발달에 미치는 영향(影響)을 구명(究明)하기 위하여 배수등급(排水等級), 토성조건(土性條件)이 상이(相異)한 대맥포장에서 토양물리성과 층위별(層位別) 뿌리 분포(分布)를 조사(調査)한 결과(結果)는 다음과 같다. 1. 배수(排水)가 양호(良好)할수록 총뿌리량은 증가(增加)되고 깊게 분포(分布)하였으며 동일(同一)한 배수등급(排水等級)에서는 토양이 세립질(細粒質)일수록 총뿌리량이 많은 경향(傾向)이었다. 2. 토양의 경도(硬度)는 가비중과 밀접(密接)한 관계가 있었으며 토성(土性)이 세립질(細粒質)일수록 유의성(有意性)이 높았다. < 식토(埴土) ($r=0.837^{**}$), 식양토($r=0.678^*$), 사양토($r=0.654^*$) > 3. 심토(深土)의 가비중과 뿌리량과는 고도(高度)의 유의성(有意性)있는 부(負)의 상관($r=-0,846^{**}$)이 있었으며 가비중이 $1.4g/cm^3$이상(以上) 되면 대맥 뿌리 발달은 현저(顯著)히 떨어졌다. 4. 심토(深土)의 가비중은 배수(排水)가 불량(不良)하고 토성(土性)이 조립질(組粒質) 일수록 감소(減少)되었으며 특(特)히 배수(排水)가 약간불량(若干不良)한 경우(境遇)와 약간(若干) 양호(良好)한 식토(埴土)에서는 기상이 20% 미만(未滿)으로 작물(作物) 생육(生育)이 불량(不良)하였다. 5. 대맥의 뿌리 신장(伸長)에는 표토(表土)는 경도(硬度), 토심(土深) 10~30cm는 가비중과 기상, 30~50cm는 기상의 영향(影響)이 컸다.

• 원예과학기술지
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• 제29권3호
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• pp.201-210
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• 2011

This experiment was conducted to investigate physical and chemical characteristics by volume fractions of root media using peatmoss, perlite, and vermiculite, along with effects on the growth of pot chrysanthemums (Dendranthema ${\times}$ grandiflorum 'Vemini') in a C-channel mat irrigation system. To evaluate the physico-chemical properties of 20 root media, the bulk density, particle density, total pore space, pore space, ash content, organic matter, pH, and electrical conductivity were measured and data were analyzed using principal component analysis (PCA). PCA scores revealed that physico-chemical properties changed by the blending of peatmoss, perlite, and vermiculite. The 20 root media were divided into three main groups by hierarchical cluster analysis. At the end of the experiment, the pH and EC of the root media were measured from media divided into four layers. The pH of root media without plants showed a strong linear relationship and the pH of root media with plants increased exponentially. The change of EC in the root medium was indicated as a hyperbolic curve. Plant growth characteristics according to growth in the 20 root media were analyzed by PCA. It was found that the mixing ratios of the root media affected plant growth characteristics. Therefore, mixing ratio is an important factor for pot-plant production in a subirrigation system.

• Communications for Statistical Applications and Methods
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• 제17권2호
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• pp.223-229
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• 2010

We consider the asymptotic results of the variance ratio statistic when the underlying processes have moving average(MA) unit roots. This degenerate situation of zero spectral density near the origin cause the limit of the variance ratio to become zero. Its asymptotic behaviors are different from non-degenerating case, where the convergence rate of the variance ratio statistic is formally derived.

• 생물환경조절학회지
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• 제25권2호
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• pp.100-105
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• 2016

양파 정식기 작업에 적합한 상토 개발을 위해 원예용 유기질 주재료(피트모스, 코이어)의 적합성을 조사했다. 유기질 재료를 무기질 재료(황토 등)와 혼합하여, 묘 출현율, 생육 및 기계정식 적응 특성 등을 조사하였다. 조사 결과 피트모스 혼합 처리구, 코이어 혼합 처리구 모두 묘 출현율, 생육 및 상토 용적밀도에서 유사했으나, 피트모스 혼합 처리구가 코이어 혼합 처리구에 비해 더 높은 상토 응집성을 보였다. 피트모스 혼합 상토의 높은 응집성은 양파 묘 정식 시 뿌리부 무게 증가 등의 효과를 가져와서 정식기 작업 효율성을 증진시키는데 도움을 줄 수 있을 것이라고 생각된다. 이러한 이유로, 양파 정식기 작업에 적합한 상토 개발 시 피트모스를 유기질 주재료로 선정하는 것이 적합하다고 최종 판단하였다.