• Korean Journal of Agricultural Science
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• v.8 no.1
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• pp.3-10
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• 1981

In order to analyze growth and yield of rice population at the stand point of productive ecology, productive structure and growth rate of rice plants and effects of their related factors were studied. The results obtained were summarized as follows: 1. High crop growth rate was maintained throughout growing season when rice plants grew in population compared to a single rice plant. Since crop growth rate in rice stands were also higher at ripening stage, higher yields were obtained. 2. Higher crop growth rate of rice plants in population was maintained by the increase of leaf area rather than by net assimilation rate. 3. As the overgrowth of upper leaves of plant population in some rice varieties transmission of light into lower leaves was inhibited and thus most of them were eventually died before flowering. 4. In the case of rice population, the ratio of productive organ to non-productive organ, light transmission rate and nitrogen contents of active leaf blade were lower than individual rice plants under isolated condition.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.195-195
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• 2017

The water in the crop cultivation shows difference according to the variety of crop, cultivations period and climatic condition. The growth and development, quantity and fruit enlargements are affected by soil water conditions. In previous study, leaf area and photosynthesis are decreased by lower soil moisture. Other research reported that excess moisture condition at vegetative and reproductive growth period in cultivation of soybean caused highest reduction in crop growth rate (CGR) and dry weights of plant parts. In particular, the damage was bigger during vegetative growth stage than reproductive growth period. Soybean (Glycine max (L.) Merill) is useful and popular crop throughout the world. It is very popular crop in Korea, China, Japan and other Asian countries. Soybeans used in various way including soybean sprouts, paste, soymilk, oil and tofu. Two soybean cultivars grown in four different irrigation conditions were determined for physiological responses. In this study, we examined leaf area (LA), leaf dry weight (LDW), specific leaf area (SLA), root dry weight (RDW) and shoot height (SH) in different water conditions. 50mL/9day irrigation periods showed the lowest contents in LA, LDW, RDW, SH. Water deficit caused increase of leaf Water saturation deficits (WSD), Cheongjakong 3 and Taekwangkong showed increase of leaf water saturation deficits (WSD) in drought conditions and leaf water potential and stomatal conductance were decreased. Photochemical efficiency was decreased in 50mL/1day irrigation condition while, there was decrease of growth and development in 50mL/9day with drought.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.4
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• pp.390-398
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• 2018

Miscanthus is a perennial energy plant that reproduces via rhizomes and has C4 metabolism. The flowering pattern of a wild type M. sacchariflorus (WTM) is affected by environmental conditions such as photoperiod and soil water status. Geodae-Uksae 1 (Geodea), which is a new M. sacchariflorus cultivar, has a lower heading rate than WMS; however the mechanism with why this happens is unknown. To confirm the effects of drought or waterlogging stresses on the growth of WTM and Geodea at the reproductive stage, we investigated variations in morphological characteristics and nutrient contents of the two Miscanthus species after four months of three water treatments. Morphological traits of the two Miscanthus species under the drought condition were similar to those under the control condition. But, the height of Geodea increased by 30% in response to the waterlogging stress. In WTM, the heading rate under the drought condition was lowest, while there was no significant difference between the waterlogging and control conditions. In the two Miscanthus species, nutrient contents, such as sucrose, total N, $P_2O_5$, K and Mg, were the highest under the drought condition, wherea Ca and Mg contents under the waterlogging condition were more than three times lower than those under the drought condition. The current study results showed that drought stress accelerated senescence and then inhibited nutrient mobilization in WTM, while waterlogging stress promoted the growth. This study is the first report to confirm that waterlogging stress promotes flowering of M. sacchariflorus.

• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.290-297
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• 2010

The effect of supplemental light such as metal, Na and fluorescent lamp on the growth and productivity of tomato for 5 hours a day The growth rate of tomatoes under artificial light were increased 6~10% rather than the growth rate of tomatoes under no light treatment. Also the quantity and productivity of tomatoes under artificial light were increased rather than the quantity and productivity of tomatoes under no light treatment. Increasing profitability per 10a under artificial light were 9.4~28.2 million won.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.5
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• pp.431-436
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• 1994

The objective of experiment was to investigate the effects of sowing dates on forage yield and growth characteristics of rye in paddy field cultivation in midwest region of Korea. The field experiment treated with 5 levels of sowing dates was carried out at Yesan from october 1990 to june 1991. The field emergence rate and winter survival rate were decreased with delay in sowing dates by the days from sowing to emergence were took a long period of time. The crop growth rate were increased with early in sowing date. The fresh and dry weight of rye were increased with early in sowing date, but there was no significant differences between sowing date from Oct. 5 to Oct. 25. The highest fresh yield was obtained at flowering stage and the highest dry yield was obtained at milky stage. The ratio of leaf blade and leaf sheath in rye plant were decreased with earlier sowing date and delayed harvest, but the ratio of stem and inflorescence was vice versa.

• Proceedings of the Korean Society of Crop Science Conference
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• 2004.04a
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• pp.104-105
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• 2004

[ $\bigcirc$ ] In the phenology model of ORYZA2000, the effect of photoperiod on the developmental rate was a little ignored because most crop parameters were measured with IRRI varieties which are insensitive to photoperiod, therefore it is very difficult to apply this phenology model directly to Korean varieties which are usually sensitive to photoperiod. $\bigcirc$ After introducing PPFAC and PPSE to improve the phenology model, the precision of heading date prediction was improved but not satisfied. $\bigcirc$ In the growth simulation using data from several regions, yield tended to be overestimated under high nitrogen applicated condition. $\bigcirc$ The precision of yield was much improved by introducing nitrogen use efficiency, but still different between regions because of different soil fertility or property of irrigation water between regions

• Korean Journal of Agricultural Science
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• v.42 no.4
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• pp.299-304
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• 2015

This study was conducted to investigate growth characteristics to develop the technique to select resistant cultivar by wet injury at an early stage through the automatic irrigation maintaining 30, 20, 10 kPa respectively using native variety, Chunpoong, Yunpoong, Gumpoong and Sunun. The aerial growth was decreased at 10 kPa compared to 30 kPa. In addition, the survival rate was decreased by 66.6%, 62.3%, 33.8% at 30, 20, 10 kPa, respectively. The survival rate of Chunpoong and Gumpoong were higher than others at 10 kPa. While root growth characteristics such as root length, root weight, number of lateral root and side root were tended to decrease, root diam was no significant or increased. And the more humid condition is, the more the incidence rate of rusty root and rough skin were tended to increase. The epidermal thickness of Chunpoong and Gumpoong was increased but the figures of native variety, Yunpoong and Sunun were decreased at 10 kPa compared to 30 kPa. But, the tissue stiffness of root was decreased at 10 kPa compared to 30 kPa.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.5
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• pp.389-393
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• 2004

This study was carried out to investigate the difference of growth characteristics, yield and extract content between upland and paddy ginseng cultured with 4­year-old ginseng in 2003. Although upland ginseng showed larger variation in yield than that of paddy ginseng, the average of it was greater than that of paddy ginseng because it showed better growth of aerial part and higher survival rate than that of paddy ginseng. Moisture content of fresh root was $71.8\%\;(68.5\~73.1\%),\;and\;72.7\%\;(70.2 \~74.9\%)$ on average in upland and paddy ginseng, respectively. Paddy ginseng showed higher hardness in taproot, and higher rate of rusty colored root than that of upland ginseng. The ratio of taproot dry weight in upland ginseng was smaller than that of paddy ginseng, while that of lateral root was larger in upland ginseng. Ratio of marketable root (>60g) to total harvested roots was $13.7\%\;(0.82\~8.0\%)\;and\;7.7\%\;(1.6\~12.6\%)$ in upland and paddy ginseng, respectively. Extract content did not show distinct difference between upland and paddy ginseng, but it showed large variation from $16.1\;to\;25.1\%$ in taproot, and from $24.2\;to\;32.5\%$ in lateral root depanding on the ginseng field examined.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.326-331
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• 2018

Crop growth models are useful tools for understanding and integrating knowledge about crop growth. Models for predicting plant height, net photosynthesis rate, and plant growth of quinoa (Chenopodium quinoa Willd.) as a leafy vegetable in a closed-type plant factory system were developed using empirical model equations such as linear, quadratic, non-rectangular hyperbola, and expolinear equations. Plant growth and yield were measured at 5-day intervals after transplanting. Photosynthesis and growth curve models were calculated. Linear and curve relationships were obtained between plant heights and days after transplanting (DAT), however, accuracy of the equation to estimate plant height was linear equation. A non-rectangular hyperbola model was chosen as the response function of net photosynthesis. The light compensation point, light saturation point, and respiration rate were 29, 813 and $3.4{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, respectively. The shoot fresh weight showed a linear relationship with the shoot dry weight. The regression coefficient of the shoot dry weight was 0.75 ($R^2=0.921^{***}$). A non-linear regression was carried out to describe the increase in shoot dry weight of quinoa as a function of time using an expolinear equation. The crop growth rate and relative growth rate were $22.9g{\cdot}m^{-2}{\cdot}d^{-1}$ and $0.28g{\cdot}g^{-1}{\cdot}d^{-1}$, respectively. These models can accurately estimate plant height, net photosynthesis rate, shoot fresh weight, and shoot dry weight of quinoa.

• Korean Journal of Medicinal Crop Science
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• v.28 no.2
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• pp.111-118
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• 2020

Background: Cnidium officinale is a medicinal crop sensitive to high temperature. It is necessary to develop environment control technology that can reduce environmental stresses such as high temperature. This study was conducted to develop technology for stable production of Cnidium officinale by reducing damage owing to high temperature by applying shading treatment of varying duration, and structure. Methods and Results: Black shading nets were used from May to September or November; shading structures such as pillar, flat roof, and tunnel type structures were installed. Environmental changes, rate of photosynthesis, and growth characteristics were investigated. The shading treatment reduced temperature by 3℃. The rate of photosynthesis and yield with shading treatment were higher by 134% and 127%, respectively, than those with full sunlight. The ratio of shading area ranged from 50% to 71% according to the type of shading structure. The effect of environmental control on growth varied depending on the type of shading structure. Conclusions: The shading treatment reduced damage owing to high temperature, shading rate of 55% - 75% was recorded between the period May - September, and the flat roof type shading structure was considered the most suitable among shading methods.