• Journal of Bio-Environment Control
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• v.22 no.3
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• pp.228-233
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• 2013

This study was conducted to examine the effect of light intensity and photoperiod of white LEDs as the artificial light source on the growth of leaf lettuce (Lactuca sativa L.) 'Seonhong Jeokchukmyeon' in a closed-type plant production system. Seedlings, transplanted at a density of $20cm{\times}20cm$ in a completely randomized design, were grown under white LEDs (FC Poibe Co. Ltd., Korea), at one of the 3 light intensities (100, 200, or $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$), and each with one of 3 photoperiods [12/12, 18/6, or 24/0 (Light/Dark)]. Plants were cultured for 22 days under the condition of $21{\pm}2^{\circ}C$, $60{\pm}10%$ RH, and $400{\pm}50{\mu}mol{\cdot}mol^{-1}\;CO_2$. The greatest leaf length and width, fresh and dry weights, and total anthocyanin content were obtained in the 24/0 photoperiod, regardless of the light intensity. Length of the longest root, fresh and dry weights, and number of leaves were greater in light intensity of $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ than 100 or $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Chlorophyll value was the greatest in the photoperiod 12/12 than 18/6 or 24/0. The results obtained suggest that plant grew the best kept by light intensity at 200 or $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, and photoperiod of 12/12 or 18/6.

• Korean Journal of Soil Science and Fertilizer
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• v.5 no.1
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• pp.9-15
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• 1972

Comparative analyses of canopy structure were conducted using newly bred high yield rice cultivars (IR 667-Suwon 213 and 214) and commercial varieties (Jinhung and Paldal) under the field condition. "Canopy score" as criteria of canopy structure was proposed. The results were summerized as follows: 1. IR667 line (IR8${\times}$Taichung Native 1${\times}$Yukara) showed lower canopy height, greater tiller openness, smaller leaf openness and leaf length ratio (flag leaf/3rd), shorter 4th and 5th internode length, greater diameter of 5th internode, consequently greater leaf area index, panicle weight and leaf weight ratio (leaf/leaf sheathculm) as merits, and greater leaf width, smaller leaf number(number of leaf/$m^2$)and specific leaf area($cm^2/g$) and faster destruction of canopy by senescence as demerits comparing with commercial varieties. 2. IR 667 line showed much higher "Canopy score", subsequently higher yield. 3. The quality of individual leaf was better in the commercial varieties indicating that the best combination for the better yield would be the leaf of commercial varieties with the structure of IR667 line.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.3
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• pp.173-178
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• 2003

To determine the optimum $\textrm{P}_2\textrm{O}_5$ rate for dry matter production of Achyranthes japonica Nakai a medicinal plant, in Jeju island, plants were grown in 2001 under ten fertilizer treatments comprising of two N (90, and 180kg/ha) and five $\textrm{P}_2\textrm{O}_5$ (0, 100, 200, 300, and 400 kg/ha) levels. Plant height leaf length and width, stem diameter, and main root length and diameter were not significantly affected by $\textrm{P}_2\textrm{O}_5$ rate while $\textrm{P}_2\textrm{O}_5$ fertilization of 100 kg/ha increased the number of branches, spikes, and roots per hill by 18,38 and 43%, respectively, compared with the unfertilized $\textrm{P}_2\textrm{O}_5$ treatment and decreased with further increases in $\textrm{P}_2\textrm{O}_5$ rate. The number of roots per hill was greatest with the application of 200kg $\textrm{P}_2\textrm{O}_5$. The highest utricle dry matter yield (2.92 t/ha) was obtained with the application of 100kg $\textrm{P}_2\textrm{O}_5$. However, as $\textrm{P}_2\textrm{O}_5$ rate increased from 0 to 100 and 200kg/ha, root dry matter yield increased from 2.36 to 3.55, and 3.80 t/ha, and then decreased to 3.14, and 2.86 t/ha at 300, and 400kg $\textrm{P}_2\textrm{O}_5$ rates, respectively. As $\textrm{P}_2\textrm{O}_5$ rate increased from 100 to 400 kg/ha, $\textrm{P}_2\textrm{O}_5$ recovery in aboveground parts decreased from 34.1 to 7.1%.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.4
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• pp.454-464
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• 1986

To find main factors to affect tobacco culture and quality, NC 2326 (Nicotiana tabacum L.) was cultivated in Korea and in the United States under different plant density, fertilization, mulching and curing. Among the chemical characteristics of the both experimental soils, the organic matters were similar concentration in both locations but effective phosphorous contents were higher in Oxford in the United States. Plant height, length and width of the largest leaf, leaf thickness, and midrib ratios were larger in Oxford than in Suwon in Korea. Also they were larger in non mulching system than in mulching system. But the total numbers of the leaves were decreased in non mulching system. The content of nicotine was higher in the plant grown in Suwon than in Oxford. The concentrations of nicotine and sugar tend to increase in mulching system comparing of non mulching system. During the growing, the concentration of non-volatile organic acids was higher in Suwon, while it was lower in cured leaf produced in Suwon. Also the contents of total fatty acids were lower in the harvested leaf grown in Suwon, but not in cured tobacco. Forty three compounds identified among the volatile oils from these experimental samples were quantified. The concentrations of the major components related to the tobacco flavour such as damascone, damascenone, solanone, nor-solanadione, and megastigmatrienones were higher in the cured tobacco produced in Oxford rather than in Suwon.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.2
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• pp.200-206
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• 1996

Experiment was conducted to get the information about physico-chemical properties of flue-cured tobacco on the degree of maturity cultivated in paddy-upland rotated field, and compared to upland ones. For the samples of this experiment, 3~4 leaves at each stalk position were harvested from the bottom of plants. Physico-chemical properties of cured leaves were determined from the samples collected at weekly intervals, and of obtained from 4 stalk positions. For the degree of maturity, harvested leaves were separated with visual characters into four classes such as immature, mature, ripe, and mellow. Regardless of stalk position, the order of shrinkage rate with length and width of leaves was mellow> immature> ripe> mature, and ripe leaves from paddy field showed higher shrinkage rate than those of upland. Nicotine and total nitrogen contents were decreased with the degree of maturity while reducing sugar content were showed a reverse tendency. Ripe leaves from paddy field had lower reducing sugar contents, comparing with upland tobacco. Filling capacity of cured leaves from paddy field was decreased with degree of maturity, but there was no difference between upland and paddy tobacco. Shatter index was increased in the oeder of immature > mellow > mature > ripe. Chemical components of cigarette smoke from paddy field tobacco were little higher in $CO_2$ total particulate matter and tar contents, while combustibility was little lower than that of upland tobacco. It was also evaluated that paddy field tobacco was unfavorable for the non-volatile organic and higher fatty acids contents comparing with upland tobacco.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.2
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• pp.156-160
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• 2020

Emergence and early growth changes of stratification condition of tea (Camellia sinensis) seeds were investigated in 7 treatments (control, pH 4, pH 10, 70% ethanol (EtOH), 10 mM H₂O₂, 100 mM H₂O₂, and physical shock (5.9 J)). Ethanol treatment was toxic and did not induce emergence. The emergence rate was 36.7% in the control, 26.7% under pH 10, 46.7% under pH 4, 48.3% under physical shock, 51.7% under 10 mM H₂O₂, and 65.0% under 100 mM H₂O₂ treatments. It was higher by approximately 178% in the H₂O₂ treatment as compared to the control. Plant height was 6.5 cm in the control, 6.6 cm under pH 10, 7.6 cm under pH 4, 7.8 cm under physical shock, 8.3 cm under 10 mM H₂O₂, and 9.1 cm under 100 mM H₂O₂ treatments. Leaf length and leaf width were also higher under the H₂O₂ treatment. Therefore, hydrogen peroxide treatment induced emergence and increased the uniformity of early growth.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.254-259
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• 1998

This study was focused on finding out the potential problems associated with organic farming system. The effect of composted animal manures subsequent inoculation of microbes on growth and yield of tomatoes (Lycopersicon esculentum Mill. 'Minicarol') were examined to develop a proper organic farming practice. Plant heights were greater in composted manure treatment than in conventional practice, whereas widths of leaves were higher in conventional field. Chlorophyll contents between various amount of composted manure application were gradually decreased and showed no significant differences after 45 days of planting. The yield in the treatment applied 12 ton of composted animal manure per 10a as pre-planting fertilizer and following microbial inoculation were only 50-60% compared to that of conventional farming. However, yield increased up to 80% when additional composts were applied to the treatment received 6 ton of composted animal manure per 10a in the middle of cultivation. Microbial inoculation followed by composted manure application induced rapid decrease of nitrogen content in soil. However, the density of microorganisms was significantly increased. Tomatoes produced through organic farming were clear in color, Further, soluble solid and acid content were increased. The highest level of acid and solids were observed in the treatment applied 12 ton of digested swine manure per 10a. Although nitrogen content including ammonium and nitrate rapidly increased after application of composts, these were significantly reduced approximately 4-5 weeks after planting. The level of phosphorus, potassium, magnesium and calcium showed gradual decrease compared to nitrogen.

• The Korean Journal of Pesticide Science
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• v.19 no.4
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• pp.399-401
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• 2015

This study investigated the plant growth promoting activity of geraniol on Chinese cabbage (Brasscia campestris ssp. Pekinensis Rupr.), Pak Choi (Brassica rapa L.), Crown daisy (Chrysanthemum coronarium L.), Iceberg lettuce (Lactuca sativa L.) and Leaf perilla (Perilla frutescens Britt.). Geraniol at 0.5 to $10mg\;L^{-1}$ promoted radical growth of Chinese cabbage Pak Choi, Crown daisy, Iceberg lettuce and leaf perilla by >30%. In the pot experiments, geraniol treatment at $20mg\;L^{-1}$ by drenching increased up to 190% of the aerial part growth promotion. By comparison, foliar application showed 124% promoting activity only at $100mg\;L^{-1}$.

• Journal of Bio-Environment Control
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• v.16 no.3
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• pp.199-204
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• 2007

This experiment was conducted to investigate the effect of nutrient solution strength on the growth of miniature multiflora P. amabilis and P. Taisuco Red Jewel at two growth stages during four months cultivation in an ebb and flow system. Early stage plants gained the biggest leaf length and width when nutrient solution strength was EC 0.5 or $1.0dS{\cdot}m^{-1}$ in P. amabilis, and EC $1.5dS{\cdot}m^{-1}$ in P. Taisuco Red Jewel. Root length and weight were the greatest when nutrient solution strength was EC $0.5dS{\cdot}m^{-1}$ in both cultivars and this trend was also found in middle stage plants. Fresh and dry weights of leaves increased as nutrient solution strength was elevated and were the greatest when nutrient solution strength was EC $1.5dS{\cdot}m^{-1}$ in P. amabilis. On the contrary elevation of nutrient solution strength decreased fresh weight of roots, being the greatest when nutrient solution strength was EC $0.5dS{\cdot}m^{-1}$. This trend was also found in P. Taisuco Red Jewel and P. amabilis at middle growth stage. The T/R ratio and chlorophyll content increased with nutrient solution strength and were the greatest regardless of cultivar and growth stage when nutrient strength was EC $1.5dS{\cdot}m^{-1}$.

• Current Research on Agriculture and Life Sciences
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• v.6
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• pp.19-24
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• 1988

The present experiment was undertaken to study the influence of light intensity on plug establishment of zoysia-82, chewings fescue and red fescue. The results obtained are summarized as follows : In chewings fescue and zoysia-82, plant height and leaf length were increased and leaf width was decreased by reducing light intensity. But in red fescue, plant height and leaf length measured at 90 and 120 days after plugging under 9% of incident light were shorter than those under 30% of incident light. Percent ground cover was decreased by reducing light intensity in chewings fescue, red fescue and zoysia-82. Each part of dry weight in three species was getting lighter by reducing light intensity. Decrease of light intensity in zoysia-82 causes increasing chlorophyll a, b, and total chlorophyll content. But red fescue and chewings fescue had the most plentiful chlorophyll under 30% of incident light. Chewings fescue and red fescue had the lowest concentration of chlorophyll a/b under natural light intensity. But zoysia-82 had the lowest concentration of chlorophyll a/b under 30% of incident light. Tillering number of chewings fescue and red fescue was decreased by reducing light intensity. Internode length of zoysia-82 was longer in the order of : 1) 30% of incident light, 2) natural light, 3) 9% of incident light. And internode diameter was decreased by reducing light intensity.