• Journal of Bio-Environment Control
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• v.19 no.2
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• pp.88-92
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• 2010

This study was conducted to compare the quality characters of 15 different tomato cultivars ('Dotearang Dia', 'Super Dotearang', 'Super sunroad', 'Hoyong', 'Mirokku', 'Baccuhs', 'Mascara', 'Poseidon', 'Radido', 'Madison', 'Rapsodie', 'Solomon', 'Amaral', 'Picasso', 'Tymaxx') and find out the correlation among the quality characters in order to get basic informations for exporting tomato. The $a^*/b^*$ value of fruit surface showed from 2.8 to 4.8, but there was no significant difference in fruit surface color value, such as $a^*$, $b^*$ and $a^*/b^*$ among the cultivars. The respiration and ethylene production rate also were not shown any significantly difference among cultivars. The firmness of fruit was higher in 'Picasso', 'Tymaxx' and 'Madison' cultivars. The contents of soluble solids was higher in 'Hoyong' and 'Dotearang Dia' cultivars. The vitamin C content was higher in 'Super Sunroad' and 'Dotearang Dia' cultivars. The titratable acidity was higher in 'Hoyong' cultivars. The sugar/acid ratio that depended on soluble contents was lower in 'Amaral', 'Picasso', 'Tymaxx' cultivars that showed lower soluble contents. Conclusionally, The firmness that was one of the most important quality character in exporting tomato was higher in European cultivars, but soluble solide and vitamin C content were higher in Japanese cultivars. The significant correlation coefficient values were determined (more than p = 0.05) between $a^*/b^*$ and other quality characters. The results suggested that surface color was the most suitable character represented tomato qualities. The high coefficient value (r = 0801) between $a^*/b^*$ and the contents of soluble solids. The firmness and the contents of soluble solids that is the most important factor for exporting showed significant negative correlation (r = -0.611).

• Journal of Bio-Environment Control
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• v.27 no.1
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• pp.54-63
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• 2018

Red and blue lights are effective wavelengths for photosynthesis in plants. In this study, we determined the effects of various combined ratios of red to blue LEDs on the quality of cherry tomato seedlings prior to transplantation, and their subsequent effects on the yield and quality of tomato fruits after transplanting. Two-week-old cherry tomato seedlings (Solanum lycopersicum cv. 'Cuty') were cultivated under various combined ratios of red (R; peak wavelength 655 nm) to blue (B; 456 nm) LEDs [red:blue = 41:59 (59B), 53:47 (47B), 65:35 (35B), 74:26 (26B), 87:13 (13B), or 100:0 (0B)] and fluorescent lamps and raised for 27 days. The cherry tomato seedlings were subsequently transplanted into a venlo-type greenhouse and cultivated for 75 days. At the seedling stage, the shoot fresh weight of seedlings in all RB combined treatments, except 0B and 59B, was higher than that of the control after 27 days of LED treatment. Shoot dry weight and leaf area also showed trends similar to that of shoot fresh weight. The stem length was significantly higher in 13B, 26B, and 35B treatments compared with the control and other treatments. In particular, the stem length of 26B plants was approximately 3.2 times longer than that of 59B plants. At 37 days after transplanting, the number of nodes was significantly higher in 26B and 47B plants, and the plant height of 26B plants was significantly higher than that of control and 59B plants. Total fruit yield in 26B plants, which was the highest, was approximately 1.6 and 1.8 times higher than that in control and 59B plants, respectively. Thus, the results of this study indicate that various combined ratios of red to blue LEDs directly affected to the growth of cherry tomato seedlings and may also affect parameters of reproductive growth such as fruit yield after transplantation.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.5
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• pp.500-506
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• 2008

Enhanced phytoremediation with EDTA or PSM(Phosphate solubilizing microorganism) was studied using green foxtail (Setaria viridis) in columns packed with 1,200 mgPb/kg contaminated soil to investigate the effects of EDTA or PSM on the plant uptake and vertical migration of Pb. EDTA, equimolar amount of total Pb in the column soil, was administered in two methods: the one was treated with 1/6 aliquots of the equimolar EDTA every week for 6 weeks and the other was treated with single dose of the equimolar EDTA before 14 days of harvest. The results showed that higher concentrations of Pb accumulated in the biomass of green fowtail after the chemical or biological treatment. The plant-root Pb concentration in PSM treatment(M), EDTA aliquot treatment(ES), and single dose treatment(E) was 2.6, 3.0, and 3.3 times higher, respectively, than that in the plant-root of control(164.7 mg/kg). The plant-stem Pb concentration in the M, ES and E treatment was 27, 37, and 40 times higher than that in the stem of control(8.1 mg/kg). The translocation factor, the ratio of shoot/root Pb concentration, was 0.6 in the two EDTA treatment, 0.5 in the M treatment, and 0.05 in the control, respectively. The largest amount of Pb was phyto-extracted in the E treatment whereas vertical migration of EDTA was significant in the ES treatment. This result showed that a single large dose of EDTA before harvest serves better for enhanced phytoremediation of Pb. Although, treatment with PSM showed less Pb phytoextraction by the plant but enhanced both the growth of plants in the column and microbial dehydrogenase activity in the soils. Therefore, enhanced phytoextraction of Pb with PSM treatment can be an alternative option for EDTA treatment, which is toxic to plants and soil ecosystem.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.1
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• pp.11-17
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• 2003

pH value of sampled fogwater at source regions (above highway and road) in Yongin sites showed the lowest value and was increased after passing the forest stands. Changes of ion concentrations through the forest stands showed a lowering tendency at sampling sites. The fogwater passing the forest stands (Quercus mangolica and Pinus rigida) surrendered acid pollutants to crown and stem from the atmosphere. It was concluded that environmental moisture in the atmosphere is acidified in fogwater. The influence was extended to the pure zone, and the frequency of acid rain has increased. The forests are assumed to remove air pollutants because ion concentrations in fogwater decreased after passing the forests. The fogwater which functions as a local sink for pollutants (H$_2$SO$_4$, HNO$_3$, etc.) falling on plant surfaces is considered to effectively remove acid pollutants. But if the deposition of pollutants exceeds the capacity of purification, it would damage the forest ecosystem. Further investigation is necessary to identify tree species tolerant to acid pollutants.

• Journal of Food Hygiene and Safety
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• v.30 no.1
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• pp.28-34
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• 2015

This study is to investigate microbiological hazards which can be used as fundamental data to adequately control leeks hazards and develop leeks GAP model for those who want to get GAP system. The microbiological investigations on cultivation environments (soil and water), crops (leeks), personal hygiene (workers' hands, clothes and gloves) and working tools (boxes) have been conducted for one year, so the period was classified under non-cultivation, cultivation, and post harvest. Total bacteria was detected from soil (4.0~6.7 log CFU/g), leeks (4.6~5.1 log CFU/g), hands (ND~3.3 log CFU/hand) and gloves ($ND{\sim}5.4\;log\;CFU/cm^2$) while nothing was detected from the other samples. The coliform contamination of leeks (4.8~5.0 log CFU/g) was more high than that of soil (3.9~4.2 log CFU/g). In case of foodborne pathogens, only B. cereus was detected at the level of 0.5~4.6 log CFU/g (or hand, $100cm^2$). Fungi was observed at the level of 2.1~3.8 log CFU/g (or hand, $100cm^2$) excepting water and some working tools. These results demonstrate that the contamination of leeks is comparatively higher than that of soil sample. The reason may be the cross-contamination by biological hazards presenting on soil. Therefore, it is necessary to properly control soil and fertilizer for safety against biological hazards.

• Journal of Bio-Environment Control
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• v.9 no.4
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• pp.193-200
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• 2000

The object of this study is to investigate the quality change of sweet basil grown with selenium(Se) in hydroponic culture. Sweet basil was cultured with 1 fold herb nutrient solution as suggested by European vegetable R & D Center in Belgium. Before three weeks harvest, sodium selenate(N $a_2$Se $O_4$) was supplied to 2 and 4 mg. $L^{-1}$ in the nutrient solution. Sweet basil was stored at 1$0^{\circ}C$ using 40um ceramic film and PET (polyethylene terephalate) for 15 days in modified atmosphere(MA) storage condition. The weight loss of sweet basil was higher in non-treatment compared to Se treatments in both of two films but it was decreased over 5% in PET treatment. Se concentrations in leaf tissues increased in the response to the treated levels of N $a_2$Se $O_4$concentrations, and this tendency was appeared similar results after storage. There was no significant effect of packing materials on volatilization of Se in sweet basil. The total chlorophyll and essential oil content was increased with increasing N $a_2$Se $O_4$concentration in nutrient solution. The amount of volatilization flavor was not higher at N $a_2$Se $O_4$4mg. $L^{-1}$ treatment compare to others during storage. Se content was 112.73 ug. $g^{-1}$ dry mass at 2 mg. $L^{-1}$ treatment before storage and the decrease of Se content was observed by 50% at 15 days after storage. The condition, which N $a_2$Se $O_4$2mg. $L^{-1}$$^{plement}$ in nutrient solution during growth stage and stored with 40um ceramic film on 1$0^{\circ}C$are acceptable for maintaining of sweet basil quality. Moreover it can be a proper Se concentration for human health. Overall, Se treatment in nutrient solution has effect on promoting and maintaining quality of herb during storage life. Also, there was not significant change of essential oil compounds by volatilization of Se.mpounds by volatilization of Se.

• Journal of Bio-Environment Control
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• v.24 no.3
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• pp.173-177
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• 2015

This experiment was conducted to determined the optimum planting density for the production of high quality bitter gourd (Momordica charantia L.) adapted in spring cultivation with the unheated greenhouse condition. 'Erave' variety was planted at three different planting densities (235, 305, $380plants{\cdot}10a^{-1}$) on March 26. The training method was six lateral vines with pinching the main one. The light intensity was lower in the higher planting density than the lower one. Net photosynthetic rates of the bitter gourd leaves in the higher density were significantly lower (41 to 71%) than the lower one. There was no difference in the fruit characteristics among treatments. But the root weight was heavier in the lower planting density ($235plants{\cdot}10a^{-1}$) as 113.1g than 96.0g of the higher planting density ($380plants{\cdot}10a^{-1}$). The number of the harvested fruit also higher in the lower planting density ($235plants{\cdot}10a^{-1}$) with 60.7 than 39.9 of the higher planting density ($380plants{\cdot}10a^{-1}$). The average fruit weight was the highest in the plot of $305plants{\cdot}10a^{-1}$ as 338.7g and lowest in the lower planting density ($235plants{\cdot}10a^{-1}$) as 285.2g. The total yield of $305plants{\cdot}10a^{-1}$ density was $5,359kg{\cdot}10a^{-1}$, which was higher than $4,068kg{\cdot}10a^{-1}$ of the lower planting density ($235plants{\cdot}10a^{-1}$). Marketable yield was increased by 24% in the planting density of $305plants{\cdot}10a^{-1}$($4,767kg{\cdot}10a^{-1}$) as compared to the lower density in $235plants{\cdot}10a^{-1}$($3,629kg{\cdot}10a^{-1}$) and increased by 13% in the planting density as $380plants{\cdot}10a^{-1}$($4,137kg{\cdot}10a^{-1}$). Therefore, the planting density of bitter gourd was desirable in $305plants{\cdot}10a^{-1}$ density for the higher yield and quality in the protected cultivation.

• Journal of Environmental Science International
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• v.22 no.9
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• pp.1181-1186
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• 2013

Due to climate change, the occurrence of abnormal weather conditions has become more frequent, causing damage to vegetable crops grown in Korea. Hot pepper, Chinese cabbage and radish, the three most popular vegetables in Korea, are produced more in the field than in the greenhouse. It has been a trend that the time for field transplanting of seedlings is getting earlier and earlier as the spring temperatures keep rising. Seedlings transplanted too early in the spring take a longer time to resume the normal growth, because they are exposed to suboptimal temperature conditions. This study examined the influence of air temperature during seedling growth on the time required to reach the first fruit maturity and yield of hot pepper. Seedling plants of 'Super Manita' hot pepper was grown in temperatures $2.5^{\circ}C$ and $5.0^{\circ}C$ lower than the optimum temperature (determined by the average of temperatures for the past 5 years). Seedlings were transplanted into round plastic containers (30-cm diam., 45-cm height) and were placed in growth chambers in which the ambient temperature was controlled under natural sunlight. The growth of seedlings under lowered temperatures was reduced compared to the control. The mineral (K, Mg, P, N) concentrations in the leaf tissues were higher when plants were grown with the ambient temperature $2.5^{\circ}C$ lower than the optimum, regardless of changes in other growth parameters. Tissue calcium (Ca) concentration was the highest in the plants grown with optimum temperature. The carbohydrate to nitrogen (C/N) ratio, which was the highest (18.3) in the plants grown with optimum temperature, decreased concomitantly as the ambient temperature was lowered $2.5^{\circ}C$ and $5.0^{\circ}C$. The yield of the early harvested fruits was also reduced as the ambient temperature became lower. The first fruit harvest date for the plants grown with optimum temperature (June 27) was 13 days and 40 days, respectively, earlier than that in plants grown with $2.5^{\circ}C$ (July 10) and $5.0^{\circ}C$ (Aug 6) lower ambient temperatures. The fruit yield per plant for the optimum temperature (724 g) was the greatest compared to those grown with $2.5^{\circ}C$ (446 g) and $5.0^{\circ}C$ (236 g) lower temperatures. The result of this study suggests that the growers should be cautioned not to transplant their hot pepper seedlings too early into the field, since it may delay the time of first harvest eventually reducing total fruit yield.

• Journal of Bio-Environment Control
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• v.23 no.1
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• pp.56-59
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• 2014

Apex removal is a common practice in artichoke cultivation to harvest heads of lateral shoots. This experiment was carried out to investigate the effect of apex removal by different planting times on the growth and yield of Artichoke (Cynara scolymus L.) in open field. Two treatments (apex removal and no apex removal) at three different planting times ($1^{st}$: Sep. 27, 2011, $2^{nd}$: March 29, 2012, and $3^{rd}$: Sep. 21, 2012) were tested using 'Green Globe' variety. There was no difference in the head characteristics and the number of harvested head between the treatments. The head weight was heavier in no apex removal of 242.7 g than the apex removal of 170.8 g. The yield also increased in no apex removal by 25% (1,249 kg/10a) compared to the apex removal of 997 kg/10a at the first planting time. At the second planting time, there was no difference in the head weights between the treatments. But the number of the harvested head was higher in no apex removal with 10.8 than 8.2 of the apex removal. The yield of no apex removal was 2,660 kg/10a, which was higher than 1,848 kg/10a of apex removal. At the third planting time, the head weight increased in no apex removal with 253.5 g compared to the apex removal with 218.7 g. The yield of no apex removal was 1,405 kg/10a, which was higher than 1,148 kg/10a of the apex removal. All the tests at 3 different planting times showed that the artichoke yields were higher in no apex removal than in apex removal. Therefore, it is desirable to cultivate artichoke without removing the apex for the higher yield and labor saving in open-field cultivation in Jeju island.

• Journal of Bio-Environment Control
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• v.23 no.4
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• pp.376-382
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• 2014

This work was conducted to investigate the variation of growth and yield among three generations ($TC_0$, $TC_1$, and $TC_2$) in the field cultivation of virus-free sweetpotato (Ipomoea batatas) plants. Virus-free generations of three cultivars ('Matnami', 'Shinhwangmi', and 'Yeonhwangmi') were cultivated with $75{\times}25cm$ planting density on May 20th, covered with black vinyl film. At 30 days after planting, vine growth in $TC_0$, $TC_1$, and $TC_2$ was significantly increased as compared to the farmer's plant, and vine length in $TC_0$ showed the highest growth among treatments. At harvesting time after 120 days, vine diameter, number of node, and number of branch in $TC_0$, $TC_1$, and $TC_2$ were more increased than farmer's plant, but were not statistically significant. Fresh weight of shoot in $TC_0$, $TC_1$, and $TC_2$ was significantly increased as compared to the farmer's plant, but was not statistically significant among generations or cultivars. Number of tuber per plant and mean weight of tuber in $TC_0$ and $TC_1$ showed significant increasement, but that in $TC_2$ did not show significant difference as compared to the farmer's plant. Weight of tuber per plant in $TC_0$, $TC_1$, and $TC_2$ was significantly increased as compared to the farmer's plant. Marketable yield, percentage of marketable tuber, and percentage of small tuber (40 to 200g) in $TC_0$, $TC_1$, and $TC_2$ was significantly increased as compared to the farmer's plant. The large tuber over 300g showed the lowest percentage in $TC_0$. Marketable yield in $TC_2$ was significantly decreased as compared to $TC_0$, and was not significantly different as compared to the farmer's plant. Marketable yield in 'Matnami' was highest among cultivars. From this results, Farmers are required to renew every three years to maintain the yield and quality of virus-free plants. However, the exchange period of virus-free plants is desirable to renew every 2 or 3 years according to the degree of virus reinfection.