• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.1
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• pp.9-15
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• 2000

The objective of this study is to evaluate the use of RADARSAT and Landsat TM data for the monitoring of rice growth. The relationships between backscatter coefficients($\sigma$$^{0}$ ) of RADARSAT data and digital numbers (DN) of Landsat TM and rice growth parameters were investigated. Radar backscatter coefficients were calculated by calibration process and then compared with rice growth parameters; plant height, leaf area index (LAI), and fresh and dry biomass. When radar backscatter coefficient ($\sigma$$^{0}$ ) of rice was expressed as a function of time, it is shown that the increasing trend ranged from -22--20dB to -9--8dB as growth advances. The temporal variation of backscatter coefficient was significant to interpret rice growth. According to the relationship between leaf area index and backscatter coefficient, backscatter coefficient underestimated leaf area index at the beginning of life history and overestimated, at the reproductive stage. The same increasing trend between biomass and backscatter coefficient was shown. From these results, RADARSAT data appear positive to the monitoring of rice growth. Each band of time-series Landsat TM data had a significant trend as a rice crop grows during its life cycle. Spectral indices, NDVI[(TM4-TM3)/(TM4+TM3)] and RVI(TM4/TM2), derived from Landsat TM equivalent bands had the same trend as leaf area index.

• Horticultural Science & Technology
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• v.32 no.3
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• pp.330-339
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• 2014

Growth and anthocyanins of lettuce (Lactuca sativa L., 'Mid-season') grown under LED lamps with blue light in the range of 430-470 nm or with red light in the range of 630-670 nm were analyzed in this study. Cool-white fluorescent light was used a s the control. P hotosynthetic photon flux, p hotoperiod, air temperature, relative humidity, and $CO_2$ concentration in a closed plant production system were $201{\pm}2\;{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, 16/8 hours (day/night), $22/18^{\circ}C$, 70%, and $400{\mu}mol{\cdot}mol^{-1}$, respectively. At 21 days after light quality treatment, growth characteristics and anthocyanins content of lettuce as affected by the peak wavelength of blue or red LED were significantly different. Among peak wavelengths treated in this stusy, R1 treatment (peak wavelength 634 nm) and R6 treatment (peak wavelength 659 nm) were effective for increasing leaf width, leaf area, shoot fresh weight, and photosynthetic rate of lettuce. B5 treatment (peak wavelength 450 nm) and B4 treatment (peak wavelength 446 nm) increased the anthocyanins concentration and chlorophyll content in lettuce leaves, respectively. Anthocyanins in lettuce leaves increased linearly with decreasing hue value of leaf color and with increasing SPAD value of lettuce leaves. From these results, it was concluded that the red LED with peak wavelengths of 634 nm and 659 nm and the blue LED with peak wavelengths of 450 nm can be used as potential light spectra for increasing the yield and anthocyanins accumulation of leafy vegetable.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.1
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• pp.33-42
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• 2005

A field experiment was conducted to evaluate growth characteristics, forage production and crude protein yield according to cutting time of Soghum ${\times}$ Sudangrass Hybrid, and decide ideal harvesting time for use of soiling and silage. Experiment design was arranged with 7 different treatment T1(150 m), T2(200 cm), T3(boot), T4(heading), T5(milk), T6(dough) and T7(yellow stage), as a randomized block design. The results were as fellows : Cutting times of utilization during the course of a year was 4 times at T1 and T2, 3 times at T3 and T4, and 2 times at T5, T6 and T7. Accumulative plant length was the highest at T2(666cm), but T3 was the lowest as 402 cm. Mean Leaf length was the highest at T5(82.1 m) and lowest at T7(T1.8 m). Mean leaf width was the highest at T2 and lowest at T6. Stem diameter was orderly ranked as T3(10.7 mm)>T1(9.5)>T2, T5(9.3>T6(8.9)>T7(8.6)>T4(8.5). Stem hardness was orderly ranked as $T7(3.2 kg/cm^2$>T5, T6(2.3)>T3, T4(1.5)> T2(0.6)>T7(8.6)>T1(0.5). Mean of leaf number and leaf ratio was the highest at $T3(8.1\%)$ and $T2(45.3\%)$, respectively. The highest yield of fresh and dry matter was obtained at T4 and T6 as 113,246 and 24,249 kg/ha, respectively(P<0.05), and e lowest at T7 and T1 as 82,675 and 13,006 kg/ha, respectively(P<0.05). Crude protein yield was highest at T6(1.456 kg/ha) and lowest at T3 as 1,189 kg/ha. As mentioned above the result T1, T2 and T3 could be recommended as use of soiling, and T5, T6 and T7 as silage.

• Journal of Bio-Environment Control
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• v.25 no.3
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• pp.139-145
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• 2016

The objective of this study was to compare the growth and light use efficiency of red leaf lettuce grown under three types of combined light-emitting diodes (LEDs) and fluorescent lamps (FL) in a closed-type plant production system. The eighteen days-old lettuce seedlings of red leaf lettuce (Lactuca sativa L., 'Jeokchima') were transplanted to the close-type plant production system equipped with three types of combined LEDs with red (R, 655 nm), blue (B, 456 nm), green (G, 515 nm), and white (W, 456 nm + 558 nm) (R:B=8:2, R:W:B=8:1:1, R:G:B=8:1:1) and FL. The seedlings were grown under normal growth conditions ($20^{\circ}C$, $181{\pm}4{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, 12 h photoperiod) for four weeks. Lettuce plants grown under FL had significantly higher leaf shape index than those under all LED treatments. Although growth of shoots and roots was not show any significant difference among LED treatments, all of the LED treatments induced about 34% higher shoot fresh weight than that of the FL. On the other hands, the total power consumption of FL was 145 kW for 4 weeks, while the mean value of LED treatments was 54 kW, which was about 3 times lower value than that of the FL. The light use efficiency based on dry matter in LED treatments was about 34 mg/W and this was about 3.5 times higher energy saving value than the FL. In conclusion, this study showed that irradiation of optimal combined LEDs in closed-type plant production systems can improve the lettuce growth as well as maximize in light use efficiency through energy saving than the FL.

• Korean Journal of Medicinal Crop Science
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• v.8 no.4
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• pp.362-372
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• 2000

This study was conducted to obtain the basic information on the production of high yield and qualitied yam in Andong, major yam-producing district, in Kyongbuk province, using three major Yam cultivars, such as Danma, Jangma and Alata (round type). Alata showed the longest tuber width while Jangma showed the longest tube length. Danma showed the highest tube yield at 2,123 kg/10a. Tubes of Alata had higher dry ratio than those of other cultivars, suggesting that Alata could be used as good processing materials. Characteristics of top parts, such as vine length, leaf number, and lateral vine number showed typical sigmoid curves. Tuber characteristics such as length, width and fresh weight of tuber were linearly increased as the growth period was progressed. Relative growth rate (RGR) for new tuber and stem reached the highest value at 86 DAT (days after transplanting). There were similar tendencies among the cultivars in net assimilation rate (NAR). The highest crop growth rate (CGR) was appeared at 156 DAT regardless of cultivars. In the changes of leaf area ratio (LAR), there were significant differences among three cultivars. LAR were decreased at 86, 106 and 136 DAT for Alata, Danma and Jangma, respectively. However, specific leaf weight (SLW) was greatly increased at 176 DAT, and leaf area index (LAI) was decreased at 156 DAT in all cultivars.

• Journal of Bio-Environment Control
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• v.31 no.2
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• pp.104-113
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• 2022

Plants under the genus Orostachys have been known as medicinal plants. This study deems to determine the growth and leaf color of Orostachys japonica and O. boehmeri when subjected to various LED light sources. A total of seven LED light treatments were used, i.e. red (630 nm), green (520 nm), blue (450 nm), purple (650 and 450 nm), 3000 K white (455, 600 nm), 4100 K white (455, 590 nm), and 6500 K white (450, 545 nm) LEDs. Results showed that O. japonica plants showed favorable growth under 4100 K white LED, while O. boehmeri plants had a positive growth response under white light LEDs (3000, 4100, and 6500 K). In leaf color analysis, the use of green LED showed the greatest change in CIELAB L^* and b^* values which were relatively higher compared to other treatments indicating that leaves turned yellowish. Further statistical analysis using Pearson's correlation also suggested that there is a small negative association between dry weight and b^* values of O. japonica, and a negative moderate association between plant weights (fresh and dry weight) and leaf color (L^* and b^*) and positive association between said plant weights and a^* color values of O. boehmeri. Therefore, it is recommended to cultivate O. japonica under 4100 K white LED and O. boehmeri under 3000, 4100, 6500 K white LEDs.

• Journal of Bio-Environment Control
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• v.32 no.3
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• pp.234-241
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• 2023

This study was conducted to investigate the growth of lettuce (Lactuca sativa L.) and Korean mint (Agastache rugosa Kuntze) with microbubble in a closed-type plant production system (CPPS) with a deep flow technique (DFT). Lettuce and Korean mint were grown in CPPS for 23 days. Microbubble was treated for 5 minutes daily at 9:00, 13:00, and 17:00 for 16 days. The leaf length, leaf width, leaf area, and fresh and dry weights of lettuce and Korean mint were significantly lower in microbubble than in the control. The total root length, root surface area, and the number of root tips of lettuce and Korean mint were significantly lower in the microbubble than in the control. In the case of average root diameter, there was no difference between the treatments of lettuce. However, Korean mint significantly increased in thickness in the microbubble treatment, indicating variations among the different crops. The results of the research indicated that microbubble treatment in the DFT inhibited plant growth by inducing abiotic stress in lettuce and Korean mint.

• Journal of Food Hygiene and Safety
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• v.38 no.3
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• pp.164-169
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• 2023

Vegetables are rich sources of dietary fiber, which exhibit various health benefits. In the Republic of Korea, vegetables are consumed after cooking using different methods. However, they are most commonly eaten raw or blanched. In this study, chamnamul, sesame leaf, Fischer's ragwort, burdock root, and garlic stem from Korea were analyzed according to the Korean Food Code, and changes in dietary fiber content after blanching were compared. Blanching reduced the total dietary fiber (TDF) content in chamnamul (from 3.67±0.03 to 2.61±0.14 g/100 g), burdock root (from 4.95±0.40 to 3.89±0.10 g/100 g), and sesame leaf (from 4.32±0.12 to 3.65±0.17 g/100 g), but increased it in Fischer's ragwort (from 6.09±0.49 to 6.43±0.01 g/100 g) and garlic stem (from 4.52±0.35 to 5.09±0.04 g/100 g). Sucrose, glucose, and fructose were detected in the vegetables; however, sesame leaf did not have sucrose. Fresh burdock root had the highest sucrose content (1.71±0.07 g/100 g) whereas garlic stem had the highest glucose and fructose content (1.65±0.02 and 1.73±0.02 g/100 g, respectively) compared with other vegetables. Upon blanching, the free sugar content of vegetables decreased for all sugars except for sucrose, which increased in Fischer's ragwort (from 0.10±0.01 to 0.14±0.01 g/100 g) and garlic stem (from 0.76±0.00 to 0.83±0.01 g/100 g). These results can provide information on blanching-associated changes in the content of dietary fiber and free sugar in foods prepared using these vegetables.

• Journal of Bio-Environment Control
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• v.32 no.4
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• pp.353-358
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• 2023

This study aimed to investigate the growth and phenol content changes of basil (Ocimum basilicum L.) under five different light intensities and photoperiods, maintaining the same Daily Light Integral (DLI) conditions in a plant factory. Basil seeds were sown on a rockwool medium for four weeks and then transplanted. To maintain a DLI 17mol·m^-2·d^-1, light intensity and photoperiod were set at 16h-295, 18h-260, 20h-235, 22h-215, and 24h-200μmol·m^-2·s^-1 and cultivated for four weeks. The harvested results showed that basil plant height, number of lateral branches, and leaf number tended to decrease from the 16h-295 treatment to the 24h-200 treatment. Shoot fresh weight, dry weight, leaf area, leaf width, and leaf length were significantly higher in the 18 h-260 treatment. The total phenolic contents in the 18h-260 treatment was significantly higher by 51.3%, 172.7%, 111%, and 119.7% compared to the 16h-295, 20h-235, 22h-215, and 24h-200 treatments, respectively. Therefore, it is anticipated that cultivating basil under the condition of 18h-260 treatment could yield enhanced growth quality and an increase in total phenolic contents.

• Horticultural Science & Technology
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• v.34 no.2
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• pp.242-248
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• 2016

This research was conducted to determine the effects of four different substrates, expanded rice hulls (ERH), commercial substrates for strawberries (CSS), clay sand (CS), and loamy sand (LS), on the inhibition of anthracnose crown rot (ACR) in strawberry. Mother plants of 'Seolhyang' strawberry were transplanted into an elevated bed in March, 2013 and March, 2014 and the runners connecting mother plants and daughter plants were cut in early August of both years. After separation, growth characteristics of the daughter plants were measured and then each daughter plant was inoculated with conidial suspensions of Colletotrichum fructicola, one of several species of Colletotrichum that causes ACR in strawberries. The incidence of ACR as influenced by the different substrates was investigated in both years. The daughter plants grown on CSS had the highest values for shoot height, leaf area, and fresh weight. Those grown on ERH and LS substrates also displayed good above-ground growth characteristics except for fresh weight, but the daughter plants grown on CS had the poorest above-ground growth characteristics. The ERH and CS treatments resulted in the highest number of primary roots and the greatest root weight. The CSS-grown daughter plants had the highest ACR disease index, followed by the CS and LS treatments, but there were no significant differences among the three substrates. However, the ERH-grown daughter plants had a markedly lower ACR disease index on October 11, 2013 and October 7, 2014. The CSS-grown daughter plants had high nitrogen and potassium contents and low calcium content, whereas the ERH-grown daughter plants had low nitrogen levels and high silicon levels. The results of this study provide basic information on the ability of the different substrates tested to provide disease suppression of ACR in the propagation of strawberry transplants.