• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.161-167
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• 2011

The soil moisture has an important effect on growth and development of highbush blueberry (HB), mainly because the root system, devoid of root hairs, is superficial. Moreover, the texture and organic matter content of Korean soil is different from the main producing counties, such as USA and Canada. To facilitate the growth and development of HB and long-term maintenance of productivity, the research related to soil moisture condition in Korea should be the priority. This study was performed to investigate the growth properties of the HB in various soil moisture conditions in order to determine the irrigation trigger point and optimum soil water potential. The texture of soil used in this experiment was loam. For the experiments, the soil was mixed with peatmoss at a rates 30% (v/v). Irrigation was scheduled at -3, -4, -5, -8, -15 and -22 kPa soil water potential then investigated leaf macronutrient, bush growth, and fruit properties. The leaf K content of HB showed the same trend in the soil water potential, but Leaf P and Mg content was highest in -5 and -22 kPa, respectively. The productivity and growth amount of HB showed the peak at the range of -4~-8 kPa as normal distribution pattern, and greatly decreased at above -15 kPa. Total dry weight and Cane diameter were highest at -4 kPa, plant width, fruit weight and yield were highest at -5 kPa, and plant height, cane number and shoot tension were highest at -8 kPa. Soluble solids content showed same trend in the soil water potential, but titratable acidity, anthocyanins and total polyphenols were not significantly different. Therefore, the optimal soil water potential for the development and a maximum production of HB were a range of -4~-8 kPa, and the recommended ideal irrigation trigger point was within -15 kPa.

• Journal of Bio-Environment Control
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• v.24 no.4
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• pp.296-300
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• 2015

This study was conducted to investigate optimal crop loads of 'Jinok' grape for unheated plastic house culture. The crop loads of 'Jinok' grapes were managed to be 1.3, 1.8, 2.2, 2.4, and 2.6t per 10a from 2012 to 2014. We measured vine growth and berry qualities. Crop loads were not significantly affected on plant height, trunk diameter, shoot length, and the internode length of 'Jinok'. However, the maturation of berries was delayed when the crop load was higher. And the harvest date was earlier about three weeks in an unheated plastic house compared to in an open field. The average berry weight was decreased by the higher crop load although higher crop loads made higher yields showing the lowest weight at 342g with the treatment of 2.6t per 10a and the highest weight at 363g with the treatment of 1.3t per 10a. Also, the soluble solids content showed a tendency that higher crop loads brought to lower degree Brix. The contents of P, K, Ca, and Mg in grape leaves and shoots were not significantly different by crop loads. To sum up, when crop loads were under the 2.4t per 10a, the berries were harvested as a marketable fruit having $15^{\circ}Brix$ in the cultivar 'Jinok' grape. This result could help to increase grower's benefit having improved quality of fruit for the sustainable production by the established cultivation techniques for the newly developed cultivar 'Jinok'.

• Journal of Bio-Environment Control
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• v.29 no.4
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• pp.354-364
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• 2020

This study was conducted to examine the potential of inducing salinity stress on cylindrical paper pot tomato seedlings to inhibit overgrowth. Potassium fertilizers, sulfate of potash (K₂SO₄), muriate of potash (KCl), and monopotassium phosphate (KH₂PO₄), were prepared as two solutions of (5 and 10) dS·m^-1 salinity level, respectively, to investigate the influence on tomato (Lycopersicon esculentum Mill.) seedling growth. We also investigated the adaptability and survivability of treated tomato seedlings with high-salinity potassium (10 dS·m^-1 KCl) to harsh environmental conditions (water deficit, low temperature, and storage conditions). Repeated addition of high-salinity level KCl, K₂SO₄, or KH₂PO₄ markedly decreased the dry matter of shoot and root, leaf area, and net assimilate rates (NAR) but increased the stem diameter of seedlings. Among the three sources, the relative growth rate of plant height (RGR_H) was most sensitive to KCl addition; increasing salinity levels of KCl solution decreased the RGR_H of seedlings. The compactness, which directly reflects the stocky growth index, increased in KCl or KH₂PO₄ treatments. After a week's water deficit, severely wilted seedlings were observed in control seedlings (untreated with KCl), but no wilted seedlings were observed in the KCl treated seedlings, and the relative water content (RWC) of the untreated seedlings significantly decreased by 23 %, while that of the pretreated seedlings only decreased by 8 %. The increase in ion leakage of KCl treated seedlings at low temperatures was less than that of untreated seedlings. Furthermore, there was far lower damage proportion on pretreated seedlings at (9, 12, and 15)℃ storage temperatures after 20 days, compared with on unpretreated seedlings. Our results suggest that high-salinity potassium fertilizer, especially KCl, is effective in preventing tomato seedling overgrowth, while it also improves tolerance.

• Journal of Bio-Environment Control
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• v.26 no.2
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• pp.72-77
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• 2017

This study was conducted to examine the effect by application method and concentration of plant growth regulator (PGR) on the growth and runner production of strawberry (Fragaria ${\times}$ ananassa Duch. cv. Maehyang) in a velno-type greenhouse. The seedlings of strawberry were transplanted in pot ($64{\times}27{\times}18cm$) filled with commercial mixed medium (Tosilee) on February 22nd, 2016. The 6-benzylaminopurine (6-BAP) was applied with foliar spray or drench, respectively as 900, 1,200 or $1,500mg{\cdot}L^{-1}$ (50 mL per plant) at 3 weeks after transplanting. Nutrient solution was sufficiently supplied by the drip irrigation as EC $0.65dS{\cdot}m^{-1}$ for rooting during 7 days. After rooting, the 450 mL nutrient solution supplied per pot twice a day (10 min). Plant height and crown diameter of 'Maehyang' mother plant appeared no significantly difference. The other growth characteristics, such as root length, number of primary roots, leaf length, leaf width, leaf area and fresh and dry weights of the shoot or root, were significantly the greatest in the control. And, the SPAD value of strawberry was the highest as 44.2 in the drench with $900mg{\cdot}L^{-1}$. The foiler spray was more effective in runner production than drench, and the number of runners appeared high values at the 900 and $1,500mg{\cdot}L^{-1}$. Whereas, the number of strawberry plantlets was effective in the drench. The results indicate that both growth and the number of runners of strawberry plant were the best achieved by foliar spray application at the $900mg{\cdot}L^{-1}$.

• Journal of Wetlands Research
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• v.16 no.1
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• pp.61-72
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• 2014

To present a guideline on the construction and management of artificial wetlands for high biomass production, three emergent macrophytes (Phragmites australis, PA; Typha angustifolia, TA; and Zizania latifolia, ZL) were planted under two substrates conditions (general soil with and without moss peat) and two water levels (5 cm and 20 cm) and monitored for three years. ZL showed greater growth performance rather than the others not only at early growth phase in the first year [shoot height, 200 cm; above-ground dry weight (AGDW), 500 $g/m^2$] but also in the last year (ZL, 1,100 $g/m^2$; TA, 770 $g/m^2$; and PA, 450 $g/m^2$ of AGDW). ZL with rapid growth at the early growth phase was not affected by naturally introduced weeds, whereas slower and poorer growth of PA and TA at the early growth phase resulted in relatively higher introduction and establishment of natural weeds. In turn, such introduced weeds negatively contributed to the growth of PA and TA particularly under shallow water (5 cm) with the substrate condition including moss peat. We suggest a plant material with rapid and great growth at the early phase such as ZL for reducing possible negative influences by the natural weeds and wild animals for high biomass production in constructed wetlands. A pre-growing process in greenhouse prior to planting might be an useful option to raise the competitiveness of those species when planting PA and/or TA. In addition, we recommend that integrated weed management system with utilizing various options at the most appropriate timing must be applied for maintaining sustainable high biomass production at the artificial wetlands.

• Journal of Korea Foresty Energy
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• v.21 no.1
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• pp.65-75
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• 2002

The study was carried out to determine the growth and biomass production of major deciduous trees including Betula platyphylla var. japonica, Betula schmidtii, Zelkova serrata, Acer mono, Prunes sargentii, and Ligustrum obtusifolium subjected to artificial shade treatment in nursery field. The six deciduous trees seedlings grow for 2 years under different light intensity of 100%, 38-62%, 22-28%, 7-20%, and 2-6% of the full sun light intensity. The results were as follows; In the seedling heights and root collar diameters of shade intolerant species like Betula platyphylla var. japonica and Betula schmidtii, the relative growth rates of seedlings grown in full sun showed 2 times as compared with those subjected to the shade treatment of 2-6% light intensities of full sun. In the shade tolerant species like Acer mono ant Ligustrum obtusifolium, the growth performances were better in the seedlings grown in 38-62% light intensities of full sun. Total dry mass including the dry mass of leaves, shoot and root were as a whole decreased with shade treatment. The ratio of the dry mass of leaves and stem increased the dry mass of root. T/R ratio of the seedlings increased by decreasing the relative light intensity. And the T/R ratio of 2-6% light intensities of full sun was ranged from 1.1~5.0 were greater in the full sun light was ranged from 0.6~3.2. Light intensity by artificial shade treatment decreased in deciduous trees when compared on the whole, it showed tendency that SLA increases, increased that seeing resemblant tendency in LAR and LWR and changed of light intensity is strong, it increased that showed difference as statistical. But, LWR of Betula platyphylla var. japonica increased gradually and showed tendency that decreases rapidly in the shade treatment of 2-6% light intensities of full sun. This result is thought that biomass production decreased by shading treatment influenced in physiological characteristics such as leaf area and decrease of the leaf amount.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.4
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• pp.149-157
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• 2008

We investigated chlorophyll contents and growth performances of five deciduous hardwood species growing in central temperate zone of Korean forest. Cornus controversa, Fraxinus rhynchophylla, Betula schmidtii, Prunus leveilleana, and Acer mono seedlings were grown under four different light intensity regime (full sunlight, $65{\sim}72%$, $29{\sim}40%$, and, $7{\sim}12%$ of the full sunlight) for the experiment. The chlorophyll contents of all of the species were highest in $7{\sim}12%$ of the full sunlight, while lowest under the full sunlight. The relative growth rate of root collar diameter and height were decreased with increasing shading level except for Acer mono that showed the highest relative growth rate under $29{\sim}40%$ of the full sunlight. Total biomass and root volumes of the seedlings studied decreased as the light intensity decreased with different shade levels. For Acer mono, however, the biomass and root volumes were highest in $29{\sim}40%$ of the full sunlight. The relative growth rate of root comparing to shoot decreased as shading increased, and as a result, the ratio of aboveground to belowground biomass increased. As the shading level increased, specific leaf area (SLA), leaf area ratio (LAR), and leaf weight ratio (LWR) of most species increased.

• Korean Journal of Environmental Agriculture
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• v.6 no.2
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• pp.39-45
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• 1987

A water culture experiment was conducted to investigate the effect of As content in a culture solution on the water status and growth of rice plants. Rice (Oryza sativa L. Line. Iri 316) seeds were germinated in bentonite and cultivated there for 30 days. Rice seedlings were transplanted into 3.5l pots containing the culture solution on May 1, 1985 and allowed to grow without As treatment for one month. Afterwards, they were grown in a culture solution maintaining the final concentration of As, 0, 1, 5, 10 and 15mg/1 renewing in the solution dissolved sodium arsenate at intervals of 3 to 7 days. Plants were cultivated in the green house during the growing period and harvested 60 days after As treatment. The results obtained were as follows: Transpiration of rice plants was decreased with the increase of the As level in the culture solution. Stomatal diffusive resistance and leaf temperature increased with increase of As levels though the humidity and the air flow rate in leaf decreased. Air flow rate, transpiration and stomatal diffusive resistance showed a highly significant correlation with As contents in shoots and roots of rice plants: Espally The air flow rate and transpiration revealed a significantly higher correlation with As contents in the root than that in the shoot, but diffusive resistance showed adverse tendency. High levels of As in the culture solution depressed plant height, no. of tillers, leaf width and dry weight of plant remarkably. Typical symptoms of As toxicity were root discoloration, and necrosis of leaf tips and margins, and leaf rolling during the sunny daytime were also another symptoms.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.34 no.2
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• pp.87-99
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• 2016

This study was carried out to characterize 127 recently developed cultivars of Rose of Sharon (Hibiscus spp.) in Korea and foreign Countries for landscape uses. The examined factors were growth characteristics such as tree height of a 1-year grafted plant(cm), plant type, growth habit, leaf characteristics such as shape and size, flower characteristics such as color, shape, size, and red eye during 2014 and 2015 for landscape uses. The results are obtained as follows; Hibiscus hybrid 'Daewangchun', 'Daeil', 'Lohengrin', 'Yeonam', 'Joomong', 'Jina', and H. syriacus 'Honggarosu' had vigorous shoot growth and tall tree size of 100cm. New Hibiscus cultivars, Hibiscus hybrid 'Daewangchun' and 'Daeil', having vigorous growth, uniform plant habit, upright, and compact branches were developed through interspecific crosses between H. syriacus 'Samchully' (♀) and H. sinosyriacus 'Seobong' (♂). This newly developed cultivar 'Daewangchun', 'Daeil', 'Lohengrin', 'Yeonam', 'Joomong', 'Jina', and H. syriacus 'Honggarosu' having tall vigorous growth d unique flower with long red eye can be used as street tree or specimen plant in landscape. Otherwise, H. syriacus 'Tamla', 'Melrose', 'Bidan', 'Hi Lea', 'Byeollee', 'Byunghwa', 'Mibak', 'Hanyang', 'Chungam', 'Lil Kim Violet', 'Jongmoo', 'Eunhasu', Hibiscus hybrid 'Saehanseo', and Hibiscus hybrid 'Yousoon' were selected as small tree of 30~39cm. They had dwarf form in tree seemed to be suitable for pot or flower bed planting on both indoor and outdoor conditions. H. syriacus 'Antong', 'Chungjo', and 'Lil Kim' were less than 30 cm of tree size. H. syriacus 'Antong', 'Chungjo', and 'Lil Kim', characterized by its compact, upright and outwardly spreading plant habit; freely branching habit; dark green-colored leaves; good garden performance. Therefore, the new cultivars with tall and small tree size were a promising cultivar as a ground covers or pot planting as woody landscape plant.

• Journal of Korean Society of Forest Science
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• v.107 no.4
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• pp.351-360
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• 2018

This study was conducted to analyze the responses of chlorophyll contents and growth of Pinus densiflora and Quercus variabilis seedlings on distance from the well and $CO_2$ flux after the artificial $CO_2$ release. From June 1 to 30, 2016, $CO_2$ gas was injected at the rate of $6L\;min^{-1}$ at the study site in Eumseong. Chlorophyll content was analyzed in the middle of July, 2016, and root collar diameter (RCD), height (H), and biomass were measured in May and December, 2016 after planting 2-year-old P. densiflora and 1-year-old Q. variabilis seedlings in May, 2015. The chlorophyll content of P. densiflora seedlings did not show a significant correlation with $CO_2$ flux, whereas the chlorophyll content of Q. variabilis seedlings showed a significant negative correlation with increasing $CO_2$ flux (P<0.05). The RCD and H growth rates of both species showed the significant difference in the distance from the well of the $CO_2$ anthropogenic release treatment. In particular, the RCD and H growth rate of P. densiflora seedlings and the RCD growth rate of Q. variabilis seedlings increased significantly as the seedlings were closer to the well, but the H growth rate of Q. variabilis seedlings decreased significantly. In addition, as the $CO_2$ concentration in the ground increases, ${\Delta}R/S$ ratio increases in both species, suggesting that the high $CO_2$ concentration in the soil promotes carbon distribution relative to the root part. The results of this study can be used as data necessary to monitor the $CO_2$ leakage and physiological and growth responses of both species to leakage of stored $CO_2$ in the future.