• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.293-301
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• 2019

The experiment was conducted to determine the performance of DME combustion gas when used as a fuel for DME burner for raising temperature and $CO_2$ concentration in greenhouse and also to examine its effects on chlorophyll content, and fresh and dry weight of lettuce and Chinese cabbage. DME-1 and DME-2 treatments consisted of average DME flow quantity in duct were $17.4m^3min^{-1}$ and $10.2m^3min^{-1}$ respectively to greenhouse-1 and greenhouse-2 and no DME gas was supplied to greenhouse-3 which was left as control (DME-3). DME supply times were $0.5hr\;day^{-1}$, $1hr\;day^{-1}$, $1:30hrs\;day^{-1}$ and $2hrs\;day^{-1}$ on week 1, 2, 3, and 4 respectively. Chlorophyll content and fresh and dry weight of lettuce and Chinese cabbage were measured for each treatment and analyzed through analysis of variance with a significance level of P<0.05. The result of the study showed that $CO_2$ concentration increased up to 265% and 174% and the level of temperature elevated $4.8^{\circ}C$ and $3.1^{\circ}C$ in greenhouse-1 and 2, respectively as compared to greenhouse-3 due to application of DME combustion gas. Although, the same crop management practices were provided in greenhouse-1, 2 and 3 at a same rate, the highest change (p<0.05) of chlorophyll content, fresh weight and dry weight were found from the DME-1 treatment, followed by DME-2. As a result, DME combustion gas that raised the level of temperature and $CO_2$ concentration in the greenhouse-1 and greenhouse-2, might have an effect on growth of lettuce and Chinese cabbage. At end of experiment, the highest fresh and dry weight of lettuce and Chinese cabbage were measured in greenhouse-1 and followed by greenhouse-2. Similarly chlorophyll content of greenhouse-1 and greenhouse-2 were more compared to greenhouse-3. In general, DME was not producing any harmful gas during its combustion period, therefore it can be used as an alternative to conventional fuel such as diesel and liquefied petroleum gas (LPG) for both heating and $CO_2$ supply in winter season. Moreover, endorsed quantify of DME combustion gas for a specified crop can be applied to greenhouse to improve the plant growth and enhance yield.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.316-325
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• 2009

Adequate conditions of water content and aeration of container media are major environmental factors in the production of pot plant. This experiment was carried out to find optimum physical property of media for the production of small potted Ardisia in capillary mat irrigation system. The plant materials used in this experiment were Ardisia pusilla and Ardisia japonica. Seven substrates were formulated by blending perlite or fresh rice hulls at 20%, 40%, 60% (v/v) with sphagnum peat. Total pore space (TPS) increased by blending sphagnum peat with fresh rice hulls, but decreased by blending sphagnum peat with perlite. As fresh rice hull (FRH) and perlite content increased, air filled pore space (AFP) of substrate increased but container capacity (CC) decreased. Substrate blended with fresh rice hull was higher AFP than blended with perlite and the rate of increase was higher for FRH-containing substrate. As AFP increased, the $CO_2$ concentration in the pot decreased and the $CO_2$ concentration of substrate blended with FRH was higher than blended with perlite. The fresh and dry weight of Ardisia pusilla and A. japonica was the highest in the substrate contained 60% FRH, but the ratio of shoot dry weight to root dry weight was the lowest. The optimum total pore space, air-filled pore space, water holding capacity of substrate for the growth of Ardisia pusilla and A. japonica in the capillary mat irrigation system were 82.8%, 25.6%, and 57.2% respectively.

• Plant Resources
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• v.4 no.2
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• pp.97-101
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• 2001

This study was carried out to determine the effect of sowing time on the flowering, growth and yield of Schizonepeta tenuifolia Briquet. Emergence and flowering dates in the sowing time from March 30 to April 30 were earlier than those of the other sowing times. In the sowing time from March 30 to April 30, length and diameter of main stem, number of node per main stem, number of branch per plant and fresh, and dry weight of stem were greater than those of the other sowing times. Yield components such as ear length, main stem length and diameter, branches per plant, number of node and ears per plant, yield of stem in fresh and dry were the highest at the sowing time from March 30 to April 30. Optimum sowing time of Schizonepeta tenuifolia Briquet were shown to be from March 30 to April 30 in southern areas of Korea.

• Journal of Biosystems Engineering
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• v.33 no.2
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• pp.106-114
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• 2008

This study was performed to analyze the distribution of air current speed, $CO_2$ concentration, and photosynthetic photon flux (PPF) in a closed transplants production system (CTPS) for producing quality transplants. And the effect of PPF on the growth of potato (Solanum tuberosum L. cv. Dejima) plug seedlings was analyzed. Uniformity of the air current speed in CTPS was improved by installing perforated floors in duct for air circulating and by adjusting of air flow rate of the fan connected to air conditioning unit used in this study, Measured $CO_2$ concentrations were measured $409{\pm}13$, $950{\pm}25$, and $1,550{\pm}35\;{\mu}mol{\cdot}mol^{-1}$ for setting values of 400, 950, and $1,550\;{\mu}mol{\cdot}mol^{-1}$, respectively. Uniformity of PPF by adding each one the single fluorescent lamp of 20 W at both ends of the single fluorescent lamps of 40 W was highly improved. While the average PPF measured under the twin fluorescent lamps of 55 W installed at regular intervals of 10 cm was decreased by increasing the vertical distance from the lighting sources, the ratio of average PPF measured at both ends to PPF measured in the center was 74-79%. Five levels ($100{\pm}9$, $150{\pm}14$, $200{\pm}17$, $250{\pm}24$ and $300{\pm}31{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) of PPF were provided to investigate the effect of PPF on plant height, fresh weight and dry weight of potato plug seedlings produced in CTPS. Plant height was decreased by increasing PPF. Maximum fresh weight and dry weight were shown under PPF of $250{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Thus PPF of $250\;{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ was enough to produce quality potato transplants under air temperature, photoperiod, and relative humidity of $20^{\circ}C$, 16/8 h, and 70%, respectively. It was concluded that quality indices such as plant height, fresh weight and dry weight could be improved by illuminating of adequate PPF from artificial lighting sources.

• Journal of Bio-Environment Control
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• v.29 no.1
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• pp.1-8
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• 2020

The influence of growth regulators (NAA and BA) and sucrose concentrations (0, 3, 5, 7, 9%) on in vitro rapid-propagation of virus-free sweet potato [Ipomoea batatas (L.) Lam.] was investigated with single-node or shoot-tip culture of two cultivars ('Matnami' and 'Shinhwangmi'). The survival rate and growth of shoot-tip explant was also investigated under the presence or absence of light (blue and red LED = 7:3, 150±5 μmol·m^-2·s^-1 PPFD) during minimal-growth in vitro conservation at 15℃. Vine length, vine diameter, fresh weight and dry weight were enhanced without callusing of explant in the MS medium supplemented with 0.2-0.5 mg·L^-1 BA. The growth of single-node and shoot-tip explants were significantly enhanced with the increase of vine length, number of leaf, number of root, fresh weight, and dry weight in the solid medium containing 5% sucrose and 0.2 mg·L^-1 BA. Vine elongation of shoot-tip explants were highest in the liquid medium containing 3% sucrose than the solid medium. The survival rate of minimal-growth in vitro conservation was 100% in 5 months under the presence of light (LED, 150±5 μmol·m^-2·s^-1 PPFD) at 15℃, but the explants in dark condition died in 3 months. The light was absolutely necessary for the in vitro conservation under minimal-growth conditions of virus-free sweet potato plantlets at 15℃, and the high density of explants (10 plantlets per Petri Dish) was increased the efficiency of mass conservation.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.1
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• pp.123-126
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• 1993

Hand dibbling in rows produced higher (p < 0.05) fresh and dry matter (DM), fodder yield, higher plant density and cob yield than broadcasted. However, the varying seed rates (40, 50 and 55 kg/ha) did not affect (p < 0.05) the fresh and DM yield and cob yield except for 30 kg/ha seed rate which produced the lowest (p < 0.01). However, the overall average fresh fodder yield and the fresh and DM yield of cob were 24.97, 10.04 and 6.90 t/ha respectively. The overall average plant height (cm), cob/plant (nos.) plant/ha, (nos.) cob/ha (nos.) and weight (g) of one cob were 178, 1.11, 664141, 70104 and 145 respectively for both the sowing methods and the four seed rates. Crude protein contents of maize plant and cob by-products (8.12% and 7.34% respectively) indicated promising cattle feeds along with human food.

• Journal of Korean Society of Forest Science
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• v.111 no.4
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• pp.630-643
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• 2022

This study was conducted to derive the fresh weight and dry weight estimation formulas of Pinus densiflora and prepare a weight table using them. Aone-variable formula using only the diameter at breast height (DBH) and a two-variable formula using DBH and height were used to calculate the fresh and dry weight. Each equation was verified using statistics, such as fit index, standard error, and residuals. Theoptimal equation was evaluated for applicability by calculating the weight as a coefficient derived from a statistical verification. W = bD+cD² was selected for the one-variable equation, while W = aD^bH^c was selected for the two-variable equation. The fit index of the former was 0.87-0.92, while that of the latter was 0.94-0.98, both of which showed a good fit. A new weight table was prepared using the optimal estimation formula, and it was compared and analyzed with a previous weight table. Analysis results showed that Gangwon pine had higher values in the previous weight table, while pines in the central region had higher values in the newly created weight table.

• Asian Journal of Turfgrass Science
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• v.5 no.1
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• pp.23-32
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• 1991

The purpose of this study was to determine the vegetative growth of two cool season turfgrasses during summer season in Korea. Ten respective cultivars of Kentucky bluegrass [Poapratensis L.] and perennial ryegrass [Lolium perenne L.] were exposed to unshaded, 30% and 60% shade for 4odays. First mowing height was 7cm, and then clippings were harvested every ten days at the same height. Shading increased the total length of clippings of all cultivars of two turfgrasses, but fresh and dry weight were significantly decreased. The highest shoot length obtained at 30% shade in Kentucky bluegrass and at 60% shade in perennial ryegrass. 'Rugky', 'Sydsport', 'Wabash' and 'Baron' of Kentucky bluegrass and 'Repel', 'Omega II', 'Ovation', 'Linn', 'Bell' and 'Manhattan' of perennial ryegrass showed relatively high tolerance to shade. Especially, in 'Citation II' perennial ryegrass, fresh and dry weight were increased by 30% shade. The number of tillers generally decreased with increasing shade. In 30% shade, 'Midnight' Kentucky bluegrass and 'Omega II' perennial ryegrass were least reduced and 'Baron' Kentucky bluegrass and 'Pennant' perennial ryegrass were most reduced. The cultivars of lower growth habit in full sunlight showed shade tolerance compared to those of higher growth habit.

• Korean Journal of Medicinal Crop Science
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• v.23 no.4
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• pp.271-276
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• 2015

This study was conducted to investigate the effect of shading degree and rooting media on the growth of Caragana sinica and Sedum middendorffianum after cutting. In C. sinica, the highest rooting rate was obtained in cuttings planted in horticultural soil (Sunshine Mix #1) and peat moss mixture (peat moss : perlite = 1 : 1, v/v) under one layer of 35% shading and in cuttings planted in kanumatsuchi soil mixture (kanumatsuchi soil : decomposition of granite = 1 : 1, v/v) under non-shading. Whereas, regardless of shading degree, most cuttings of S. middendorffianum rooted in both horticultural soil and peat moss mixture. Cuttings of C. sinica showed the highest root length, 10.4cm in kanumatsuchi soil mixture under one layer of 35% shading but the highest fresh and dry weight of roots in kanumatsuchi soil mixture under non-shading. In S. middendorffianum, the highest root length, fresh and dry weight of root were obtained in cuttings planted in horticultural soil under non-shading. With these results, we recommended that cuttings of C. sinica should be propagated in kanumatsuchi soil mixture under non-shading and cuttings of S. middendorffianum in horticultural soil under non-shading.

• Plant Breeding and Biotechnology
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• v.5 no.4
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• pp.363-370
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• 2017

In this study, Quercus acutissima seedlings were subjected to drought for 30 days then analyzed to determine their response to water deficit. The growth phenotype, chlorophyll fluorescence response, fresh weight, dry weight, photosynthetic pigment levels, soluble sugar content, and malondialdehyde (MDA) were measured to evaluate the effects of drought on plant growth and physiology. The growth phenotype was observed by infrared (IR) digital thermal imaging after 30 days of drought treatment. The maximum, average, and minimum temperatures of drought-treated plant leaves were $1-2^{\circ}C$ higher than those of the control. In contrast, the fresh and dry weights of the dehydrated leaves were generally lower than those of the control. There were no significant differences between treatments in terms of chlorophyll a, chlorophyll b, total chlorophyll, and carotenoid levels. Nevertheless, for the drought treatment, the $F_v/F_m$ and $F_v/F_o$ ratios (chlorophyll fluorescence response) were lower than those for the control. Therefore, photosynthetic activity was lower in the dehydrated plants than the control. The drought-stressed Q. acutissima S0536 had lower soluble sugar (glucose and fructose) and higher MDA levels than the controls. These findings may explain the early growth and physiological responses of Q. acutissima to dehydration and facilitate the selection of drought-resistant tree families.