• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.177-183
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• 2010

Bum-type $CO_2$ generators are widely used in greenhouses for the purpose of $CO_2$ supply for photosynthesis and greenhouse heating. However harmful gases included in the air might give severe effects on the plant growth. For investigating the possible emission of harmful gases from commercial bum-type $CO_2$ generators, we carried out the analysis of the harmful by-products (NO, NOx, $NO_2$, CO, and VOCs) and $CO_2$ caused by using a bum-type $CO_2$ generator in greenhouses. And the harmful by-products from different type of fuels such as kerosene, LPG, and LNG were quantified. In order to minimize the uncertainties from a $CO_2$ generator, 4 different $CO_2$ generators were utilized in four plastic greenhouses and a glasshouse located at different places during the experimental works. The results showed that the concentration of NOx is proportional to $CO_2$ concentration. Levels of harmful gases in the most of greenhouses, where the new bum-type $CO_2$ generators were installed, were lower than 1.0 ppm when $CO_2$ concentration was set at 1,000 ppm. In case of LNG combustion, the concentration of CO reached out up to 300 ppm and pre-treatment for CO reduction, such as the adsorption process, would be inevitable to abate the adverse effects on plant growth.

• Journal of Bio-Environment Control
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• v.25 no.4
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• pp.302-307
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• 2016

The aim of this study was to examine the optimum wattage and installation height using nano-carbon fiber infrared heating lamp (NCFIHL) for heating energy saving and plug seedling production in plug seedling production greenhouse in winter season. NCFIHL of 700 and 900 W was installed over the bed ($1.2{\times}2.4m$) as 0.7, 1.0, and 1.3 m height, respectively, for the production of grafted watermelon seedling in venlo-type glasshouse. Watermelon (Citrullus lanatus (Thunb.) Manst.) 'Jijonggul' and gourd (Lagenaria leucantha Rusby.) 'Sunbongjang' were used as scions and rootstocks, respectively. The scions and rootstocks were grafted by single cotyledon ordinary splice grafting. Light intensity of NCFIHL was below the $1{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ in all treatment. Spectral distributions of NCFIHL presented mostly infrared area. When outside air temperature was below $10^{\circ}C$, 700 and 900 W NCFIHL installed with 0.7 m height treatment and 900 W NCFIHL installed with 1.0 m height treatment maintained the setting air temperature ($20^{\circ}C$) at night. In the result of taking thermal imaging, the grafted watermelons were getting warm fast in 900 W NCFIHL installed with 0.7 m height treatment at night. Compactness of the grafted watermelons was the greatest in 700 W NCFIHL installed with 1.3 m height treatment. The results indicate that NCFIHL installed above 1.0 m height using 700 W was suitable for production of plug seedling.

• Korean Journal of Ecology and Environment
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• v.46 no.2
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• pp.234-240
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• 2013

Increasing global $CO_2$ concentration and temperature is leading to the phenomenon of global warming and impacting the growth of plants. In order to determine the effects of global warming on the woody plants of Korea, five woody species, Pinus densiflora (Korea's dominant species), Ginkgo biloba (a commonly used street tree), Quercus glauca (dominant species in sub-tropical forests), Quercus gilva and Abeliophylum distichum (both endangered species), were grown at control (ambient $CO_2$+ambient temperature) and treatment (elevated $CO_2$+elevated temperature) conditions in a glasshouse, and were monitored for their ecological response. Shoot lengths and number of leaves were measured once a month from April to October in 2010, and were again measured in November 2011. Shoot lengths of P. densiflora, G. biloba and Q. glauca were not significantly affected by elevated $CO_2$ and temperature conditions. However. those of Q. gilva and A. distichum were both higher for plants grown under treatment than for those grown under control. The number of leaves of five woody species was not significantly affected by elevated $CO_2$ and temperature. These results indicate that P. densiflora, G. biloba and Q. glauca react more favorably than Q. gilva and A. distichum (each of which are designated as endangered plants) under global warming situations.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.44-44
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• 2017

Recently, the occurrences of extreme flooding and drought, often in the same areas, have increased due to climate change. We tested the hypothesis that wetland species could help upland species under flood conditions; that is, the roots of wetland crops may supply $O_2$ to the roots of upland crops by a series of experiments conducted in both humid Japan and semi-arid Namibia (See Iijima et al, 2016 and Awala et al, 2016). Firstly, flooding tolerance of upland-adapted staple crops-pearl millet (Pennisetum glaucum) and sorghum (Sorghum bicolor) mix-cropped with rice (Oryza spp.) was investigated in glasshouse and laboratory experiments in Japan. We found a phenomenon that strengthens the flood tolerance of upland crops when two species-one wetland and one drought tolerant-were grown using the mixed cropping technique that results in close tangling of their root systems, hereinafter referred to "close mixed-planting". This technique improved the photosynthetic and transpiration rates of the upland crops subjected to flood stress ($O_2$-deficient nutrient culture). Oxygen transfer was suggested between the two plants mix-cultured in water, implying its contribution to the phenomenon that improved the physiological status of upland crops under the simulated flood stress. Secondly, we further tested whether this phenomenon would be expressed under field flood conditions. The effects of close mixed-planting of pearl millet and sorghum with rice on their survival, growth and grain yields were evaluated under controlled field flooding in semi-arid Namibia during 2014/2015-2015/2016. Single-stand and mixed plant treatments were subjected to 11-22 day flood stress at the vegetative growth stage. Close Mixed-planting increased seedling survival rates in both pearl millet and sorghum. Grain yields of pearl millet and sorghum were reduced by flooding, in both the single-stand and mixed plant treatments, relative to the non-flooded upland yields, but the reduction was lower in the mixed plant treatments. In contrast, flooding increased rice yields. Both pearl millet-rice and sorghum-rice mixtures demonstrated higher land equivalent ratios, indicating a mixed planting advantage under flood conditions. These results indicate that mix-planting pearl millet or sorghum with rice could alleviate flood stress on dryland cereals. The results also suggest that with this cropping technique, rice could compensate for the dryland cereal yield losses due to field flooding. Mixed cropping of wet and dryland crops is a new concept to overcome flood stress under variable environmental conditions.

• Korean Journal of Soil Science and Fertilizer
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• v.13 no.3
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• pp.85-91
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• 1981

In order to evaluate effectiveness of zinc source on uptake of zinc by rice plant, a pot experiment carried out using ZnEDTA and $ZnSO_4$ in a glasshouse. The results obtained were summarized as follows: The effectiveness of zinc source on uptake of zinc by rice plants was different with different soil. Namely ZnEDTA was more efficient than $ZnSO_4$ in increasing yield of zinc and concentration of zinc in the plant grown on Jecheon calcareous soil. In case of Keumgok acid soil, however, no superiority of ZnEDTA treatment was found. The plant growing status of ZnEDTA treated calcareous soil was also shown that larger number of tillers per hill, bigger height of the plant and good yield of dry matter production than those of the plant grown on $ZnSO_4$ treatment. Regardless of the zinc source, smaller number of tillers per hill, shorter height of the plant, and the lowest yield of dry matter were shown in the treatment of zinc and straw mixed with both soils. It seemed that more applied zinc was to be fixed by the straw application resulting in poor zinc yield. The extent of the zinc fixation showed markedly in Jecheon calcareous soil.

• Korean Journal of Soil Science and Fertilizer
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• v.6 no.3
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• pp.193-197
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• 1973

1. Two desert perennial plant species (Lycium andersonii Gray and Atriplex confertifolia (Torr. & Frem) Wats.) were grown in soil in a glasshouse with different sources of Na ($NO_3{^-}$, $Cl^-$, $H_2PO_4{^-}$) to evaluate their effects upon cation-anion balance in the plants. 2. Each anion greatly increased in leaf with only minor, if any, interactions with other anions 3. The miliequivalent sum of anions measured (N. P. Cl), increased in each plant part with the soil applications. 4. Simultaneously there were usually modest increases in the me. sum of cations. 5. The cation-anion ratio was decreased markedly when $NaNO_3$ was added. The ratio was usually over one. 6. Maximum content of Cl and N in leaves with L. andersonii. was 13.5%, and 6.37% respectively, when each was added. 7. Sodium concentrations were higher for the Atriplex species than for L. andersonii. 8. There were some compensations among other cations as sodium was increased, so that a somewhat constant sum of cations was maintained although there were significant differences among different sources of Na. 9. L. andersonii appeared to be an accumulator of Li.

• Journal of Bio-Environment Control
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• v.22 no.2
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• pp.81-86
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• 2013

This experiment was carried out to select white asparagus varieties suitable for shading culture in greenhouse. Eight white and one green varieties were tested. Seeds were sown in 72-cell trays in a glasshouse on 24 Dec. 2008 and the seedlings were transplanted in a P.E house on 22 May 2009. Planting distances were 30 cm apart in a raw and 125 cm between the raws. For white asparagus production, small tunnel ($210cm{\times}160cm$) was established inside the P.E house, and covered with black and white P.E film (0.1 mm) on 5 March 2010. Days to sprouting took 5 days in 'Ravel' variety and took 16 to 18 days in 'Backlim', 'Horlim', 'Herkolim' varieties. The number of spear was highest in 'Ravel' with 6 and lowest in 'Backlim' with 3.7. The spear weight was heaviest in 'Herkolim' with 25.6 g and lightest in 'Ravel' with 15.6 g. The highest total yield was in 'Herkolim' with 296 kg/10a, followed by 'Super welcome' with 275 kg/10a and lowest in 'Rapsody' with 176 kg/10a. Marketable yields in 'Super welcome' and 'Herkolim' were 241 kg/10a and 239 kg/10a, respectively, and the yield was lowest in 'Rapsody' with 139 kg/10a. The L grade (over 20 g of spear weight) was highest in 'Herkolim'. Accordingly, 'Herkolim' was the most suitable white asparagus variety among the tested varieties for shading cultivation in greenhouse.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.4
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• pp.132-140
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• 2006

This investigation into unfermented soybeans, which were left from the soybeans used to make cheongguk-jang, was conducted to find out its availability of the application to the environmental-friendly fertilizers. The test of cultivating lettuce, using 1/5000a Wagner pot, was carried out inside the affiliated farm glasshouse, belonged to University of Chung-Nam National. The results showed that in the category of leaf length, the control and cheongguk-jang soybeans treatment plot had similar outcomes and in the category of the extract of the cheongguk-jang soybeans, it increased by about 26~33%. And in the categories of width and number of leaves it showed that the extract treatment increased by about 9~20%, in compared to the control. Finally, in the category of fresh weight, the results showed that cheongguk-jang soybean and the extract of the cheongguk-jang soybean effectively increased by about 9~27%, and that pig manure compost treatment plot with the extract of the cheongguk-jang soybean also significantly increased by about 26%, compared to the control. Accordingly, the unfermented soybean left in the production of cheongguk-jang and the extract of the cheongguk-jang soybean are considerably appeared to be valuable environmental-friendly fertilizers.

• The Korean Journal of Pesticide Science
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• v.3 no.1
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• pp.90-95
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• 1999

For the control of the greenhouse whitefly, Trialeurodes vaporariorum entomopathogenic fungi were isolated from forest soils and infected insects. We selected three strains, which showed high pathogenicity and named as SFB-582(Beauveria sp.), SFP-198(Paecilomyces fumosoroseus) and SFV-1053(Verticillium sp.) respectively. Particularly, at the concentration of $10^{7}$ conidia/ml, P. fumosoroseus SFP-198 had the highest pathogenicity, $91.4{\pm}3.5%$ in laboratory. In glasshouse application, $91.4{\pm}3.5%$ SFP-198 showed high protective values($80{\sim}90%$) regardless of developmental stages, which were similar with that of Verticillium lecanii F-903 already reported. Four kinds of formulations of entomopathogenic fungi were developed, formulation with surfactant Silwet L-77 gave best control of greenhouse whitefly(over 90%). These results suggest that P. fumosoroseus SFP-198 is a promising candidate as a microbial pesticide for the control of T. vaporariorum.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.3
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• pp.225-232
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• 2015

We evaluated the effect of mixed liquid fertilizer (MLF) on growth responses of plants and soil chemical properties. A pot experiment with red pepper (Capsicum annuum L.) using loam soil was conducted for 81 days in a temperature-controlled glasshouse, and four N fertilization treatments were laid out in a completely randomized design with three replicates: control (C), chemical fertilizer treatment (CF), and two rates (MLF-0.5 and MLF-1.0) of MLF treatment. Soils were periodically sampled and analyzed for pH, EC(Electrical Conductivity), total N, inorganic N and total C, and some growth characteristics of red peppers were measured. During the experimental periods, the pH of MLF soils was higher than that of CF soils. Soil EC increased right after application of CF or MLF, and the intial increase persisted in CF and MLF soils at the end of experiment. Soil total-N increased right after application of CF or MLF, and this initial increase persisted only in MLF-1.0 soils. Soil inorganic N content initially increased in CF or MLF-1.0 soils, but the initial increase disappeared in 56 days after transplanting. Soil total-C was maintained higher in MLF-1.0 soils and lower in CF soils than in control soils, and the intial increase in MLF-1.0 soils finally disappeared to the level of control soils. Plant height, dry weight of plant organs (shoots, roots and fruit), and the number, diameter and length of red pepper fruits were greatest in CF plants. On the other hand, the effect of MLF-application was different depending on the rate of application. However, no consistent effect of N treatments on some major elements of the organs of red peppers was observed. The amounts of N taken up by plants were 1.3 g for CF, 0.8 g for MLF-1.0, 0.5 g for MLF-0.5 and 0.4 g for control treatments. The results of this study showed that mixed liquid fertilizer (MLF) could appropriately serve as an alternative to chemical N fertilizer in red pepper cultivation.