• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.4
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• pp.329-339
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• 2021

Soybeans (Glycine max), one of major upland crops, require precise management of environmental conditions, such as temperature, water, and soil, during cultivation since they are sensitive to environmental changes. Application of spectral technologies that measure the physiological state of crops remotely has great potential for improving quality and productivity of the soybean by estimating yields, physiological stresses, and diseases. In this study, we developed and validated a soybean growth prediction model using multispectral imagery. We conducted a linear regression analysis between vegetation indices and soybean growth data (fresh weight and LAI) obtained at Miryang fields. The linear regression model was validated at Goesan fields. It was found that the model based on green ratio vegetation index (GRVI) had the greatest performance in prediction of fresh weight at the calibration stage (R²=0.74, RMSE=246 g/m², RE=34.2%). In the validation stage, RMSE and RE of the model were 392 g/m² and 32%, respectively. The errors of the model differed by cropping system, For example, RMSE and RE of model in single crop fields were 315 g/m² and 26%, respectively. On the other hand, the model had greater values of RMSE (381 g/m²) and RE (31%) in double crop fields. As a result of developing models for predicting a fresh weight into two years (2018+2020) with similar accumulated temperature (AT) in three years and a single year (2019) that was different from that AT, the prediction performance of a single year model was better than a two years model. Consequently, compared with those models divided by AT and a three years model, RMSE of a single crop fields were improved by about 29.1%. However, those of double crop fields decreased by about 19.6%. When environmental factors are used along with, spectral data, the reliability of soybean growth prediction can be achieved various environmental conditions.

• Korean Journal of Environment and Ecology
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• v.28 no.5
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• pp.574-587
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• 2014

In this study, vertical distribution patterns of Quercus mongolica Fisch. ex Ledeb. and Q. serrata Murray in Korea were recognized and possibility of introgressive hybridization and gene flow between Q. mongolica and Q. serrata in Mt. Jiri was inferred by flavonoid analyses. The most critical factor on distribution patterns was the altitude in accordance with temperature condition. A zonal distribution was recognized: Quercus mongolica zone in the upper area and Q. serrata zone in the lower area. In Central Korea, the range of vertical distribution of Q. mongolica was above alt. 100m, almost everywhere, whereas that of Q. serrata was from alt. 0 m to alt. 500(-700) m, and the species is rare above that altitude. But in Southern Korea, Q. serrata is found up to above alt. 1,000 m, whereas frequency of Q. mongolica reduces as elevation in decline and the species is rare below alt. 300 m, even though pure stands being formed on higher mountain slope. Altitudinal distribution of the two species, however, overlaps, where the two species occur together. Thirty-seven individuals of Q. mongolica and Q. serrata in Mt. Jiri and other area were examined for leaf flavonoid constituents. Twenty-three flavonoid compounds were isolated and identified; they were glycosylated derivatives of the flavonols kaempferol, quercetin, isorhamnetin, myricetin, and four compounds among the flavonoid compounds were acylated. Kaempferol 3-O-glucoside, quercetin 3-O-glucoside, quercetin 3-O-galactoside and its acylated compounds were major constituents and present in all individuals. Quercus mongolica is distinguished from Q. serrata by the presence of quercetin 3-O-arabinosylglucoside and by high concentration of three acylated compounds, acylated kaempferol 3-O-glucoside, quercetin 3-O-glucoside, quercetin 3-O-galactoside, and by relatively low concentration or lacking of rhamnosyl flavonol compounds. There are intraspecific variations in flavonoid profiles for Q. mongolica and Q. serrata, the flavonoid profiles for individuals of two species in hybrid zone (sympatric zone) tend to be similar to each other, qualitatively and quantitatively. These findings strongly suggest that gene exchange or gene flow occurs through the introgressive hybridization between Q. mongolica and Q. serrata in Mt. Jiri. Therefore, Quercus crispula, occupying morphologically intermediate position between Q. mongolica and Q. serrata, is suspected of being a hybrid taxon of two putative parental species.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.4
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• pp.370-375
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• 2016

The purpose of development new variety 'Miho' (Hordeum vulgare L.) is a favorite with livestock feed and develop varieties resistant to disease and lodging. 'Miho' was carrying out the growth habit of group III with green and mid-wide leaf. Awn that is related to preference of livestock is a semi-smooth awn. This cultivar had 96 cm of culm length, 650 of spikes $per\;m^2$. Heading date of 'Miho' was April 27, and maturing date on May 30, which were later than cultivar 'Youngyang'. It also showed strong winter hardiness, and similar resistance to shattering and bariy yellow mosaic virus (BaYMV) compared with those of check one. The best thing among the traits of a good quality with the plant green at the latter growing period. The average forage dry matter yield in the regional yield trial was about 13.1, 12.1 MT per ha in upland and paddy field, respectively, which were 9%, 2% higher than that of the check cultivar. It's also showed 6.8% crude protein, 27.1% ADF (acid detergent fiber), and 67.5% TDN (total digestible nutrients), including higher silage quality for whole crop barley. This cultivar would be suitable for the area whose average minimum temperature was above $-8^{\circ}C$ January in Korean peninsula.

• Korean Journal of Environmental Agriculture
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• v.37 no.2
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• pp.79-86
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• 2018

BACKGROUND: Chinese cabbage biosynthesizes various phytochemicals including carotenoids and glucosinolates. Environmental stress has a major effect on the growth and yields of vegetables, and can significantly affect nutritionally important phytochemicals. Phytochemicals of plants are influenced by light, temperature, carbon dioxide, and growing conditions. The aim of this study was to investigate the effect of various light sources on carotenoid and glucosinolate contents in Chinese cabbage. METHODS AND RESULTS: [Experiment I] Set the control (field control, FC) on the ground. Using acrylic sunlight, experiments were set up transparency box (field transparency, FT), red box (field red, FR) and blue box (field blue, FB). [Experiment II] Set the control (chamber control, CC) in the greenhouse. Using plant growth chamber with artificial light, experiments were set up LED red (chamber red, CR), LED blue (chamber blue, CB), LED mixed red+blue (chamber red+blue, CRB) and fluorescent (chamber fluorescent, CF). After plant growth, Chinese cabbage was harvested at 110 days after sowing (DAS). The status of plants growth (leaf length, width, fresh weight etc.) was immediately investigated. Carotenoid and GSL contents were analyzed by HPLC. [Experiment I] Results documented that the ranges of total carotenoid contents were 25.39 ~ 58.80 mg/kg dry wt for lutein, 0.84~ 4.22 mg/kg dry wt for zeaxanthin, and 3.85~18.71 mg/kg dry wt for ${\beta}$-carotene. Lutein was the highest for the content and the largest for the variation as well. [Experiment II] Results documented that the ranges of total carotenoid contents were 24.66~137.96 for lutein, 2.51~20.65 for zeaxanthin, and 8.40~49.80 mg/kg dry wt for ${\beta}$-carotene. The total carotenoid contents of CR (156.62) and CB (115.90) were 1.6~2.3 times larger than the other treatments, and ${\beta}$-carotene content was about twice as high as that of the other treatments on the CR (38.74 mg/kg dry wt.). [Experiment I] Total GSL content was the highest in FT (19.76) that was higher 1.7 times than the lowest treatment ($11.39{\mu}mol/g\;dry\;wt$.). [Experiment II] The total content of GSL was highest in CRB (4.19) and lowest in CF ($2.88{\mu}mol/g\;dry\;wt$.). In the CRB, total GSL contents ($4.19{\mu}mol/g\;dry\;wt$.) was the highest. CONCLUSION: Total and individual carotenoid and GSL contents in Chinese cabbage show significant differences under different light sources. Red and blue lights contribute to significant carotenoids expression and antioxidant activity for nutrition and health benefits. These results concluded that the introduction of varying lights affected the synthesis of important nutrient compounds in Chinese cabbage. It is predicted that the application of good light source enhances the accumulation of functional compounds.

• Journal of Korean Society of Forest Science
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• v.66 no.1
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• pp.82-94
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• 1984

The variation of stomatal density and stomatal length of four species of oaks was studied for the purpose of examining the differences among populations and among individual trees within population. Nine populations of Quercus mongolica, four populations of Q. serrata and Q. variabilis respectively, and three populations of Q. acutissima were selected in the natural stands of oaks distributed through the whole country. Twelve leaves were sampled from each of 20 trees from each population. The length of 20 stomata and ten replications of stomatal density were measured from collodion replicas of each leaf under a microscope. Average stomatal densities and lengths ranged through $600-1000/mm^2$ and $19-26{\mu}m$ respectively in all of the species studied. The stomatal densities and lengths presented significant differences statistically at the level of 1 or 5% among populations and among individual trees within population in all the species. Quercus mongolica, especially, showed large variation among populations, while Q. variabilis did very narrow variation compared to the other species. The coefficients of variation of stomatal densities and lengths among individual trees within population exhibited small values of 3.7-12.0% and 1.4-5.3% respectively in all the populations of the species. The average stomatal densities of Q. mongolica showed statistically significant correlation of multiple correlation coefficient of $R_{df{\cdot}2.6}=0.868^*$ and multiple regression equation of $Y=0.041X_1(G.M.T.S.)+0.489X_2(G.M.H.S.)+22.37$ with the sum of growing season mean daily temperature and the sum of growing season mean daily humidity of the stand studied. However the average stomatal lengths showed no relation with the same meteological variables. The figures of frequency distribution of the measurements of leaves or the mean values of individual trees did not show normal distribution curves in some populations. The curves, as well as the results of ANOVA, exhibited the differences among populations.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.12
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• pp.1769-1775
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• 2016

Aerial parts (leaves and stems) of radish are usually discarded due to the distinct undesirable flavors associated with inappropriate preparations, despite their many health benefits. In this study, we examined the role of extrusion process in the removal of off-flavors and elevation of antioxidant activity in radish (Raphanus sativus L.) leaves and stems. To optimize the extrusion conditions, we changed the barrel temperature (110, 120, and $130^{\circ}C$), screw speed (150, 200, 250, and 300 rpm), and moisture content (20, 25, and 30%). The polyphenol and flavonoid contents significantly increased in extruded radish leaves and stems (ER) under optimum extrusion conditions ($130^{\circ}C$, 250 rpm, and 20%). Under extrusion conditions, we compared off-flavors (as amount of sulfur-containing compound) levels between ER and non-extruded radish leaves and stems (NER) by an electronic nose. A total of six peaks (sulfur-containing compound) were similarly detected in both ER and NER, whereas the ER showed reduced off-flavors. Levels of glucosinolate (${\mu}g/g$), which can be hydrolyzed into off-flavors during mastication or processing, were significantly decreased in the ER. From these results, extrusion processing can be an effective method to increase anti-oxidant activity and removal of off-flavors in radish leaves and stems.

• Korean Journal of Environmental Agriculture
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• v.32 no.3
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• pp.193-200
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• 2013

BACKGROUND: Plant factory system of an artificial light type using Light-Emitting Diodes (LEDs), fluorescent light, or metal halide lamp instead of sun light is an ultimated method for plant production without any pesticides regardless of seasonal changes. The plant factory is also completely isolated from outside environmental conditions such as a light, temperature, or humidity compared to conventional greenhouse. Light-environment control such as a quality or quantity in the plant factory system is essential for improving the growth and development of plant species. However, there was little report that the effects of various light qualities provided by LEDs on Ledebouriella seseloides growth under the plant factory system. METHODS AND RESULTS: Ledebouriella seseloides seedlings transplanted at urethane sponge were grown in the plant factory system of a horizontal type with LED artificial lights for 90 days. Yamazaki solution for hydroponic culture of the seedlings was regularly irrigated by the deep flow technique (DFT) system on the culture gutters. Electrical Conductivity (EC) and pH of the solution was recorded at 1.4 ds/m and 5.8 in average, respectively during the experimental period. Number of unfolded leaves, leaf length, shoot fresh and dry weight of the seedlings were three times measured in every 30 days after beginning of the experiment. Blue LEDs, red LEDs, and fluorescent lights inside the plant factory were used as light sources. Conventional fluorescent lamps were considered as a control. In all the treatment, light intensity was maintained at $100{\mu}mol/m^2/s$ on the culture bed. Fresh weight of the seedlings was 3.7 times greater in the treatment with the mixture radiation of fluorescent light and blue+red LEDs (1:3 in energy ratio; Treatment FLBR13) than in fluorescent light treatment (Treatment FL). In FLBR13 treatment, dry weight per seedling was two times greater than in FL or BR11 treatment of blue+red LEDs (1:3 in energy ratio; Treatment BR11) during the culture period. Increasing in number of unfolded leaves was also significantly affected by the FLBR13 treatment comparing with BR11 treatment. CONCLUSION(S): Hydroponic culture of Ledebouriella seseloides seedlings was successfully achieved in the plant factory system with mixture lights of blue, red LEDs and fluorescent lights. Shoot growth of the seedlings was significantly promoted by the FLBR13 with the mixture radiation of fluorescent light, blue, and red LEDs under 1:3 mixture ratio of blue and red LEDs during the experimental period compared to conventional light conditions.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.4
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• pp.390-396
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• 2009

To select optimal shade material in paddy soil, growth characteristics and ginsenoside contents were investigated in new cultivar, 'Cheonpoong' of three-year-old ginseng cultured under three kinds of shade materials such as three-layered blue and one-layered black PE (polyethylene) net (TBPN), blue PE sheet (BPSS), and aluminium-coated PE sheet (APSS). The order of light transmission ratio and air temperature by shade materials were BPSS > APSS > TBSB among three shade materials. Average soil water tension in PDC and IDC was 64 mbar (absolute soil moisture, 25%) and 123 mbar (absolute soil moisture, 17%), respectively, and soil water tension in IDC was changed more distinctly than that of PDC by season and shade materials. Yield in PDC was distinctly decreased more than that in IDC because of the increase of discolored-leaf and rusted-root ratio. BPSS and TBPN among three shade materials were the most effective on the increase of yield in PDC and IDC, respectively. Ratio of rusty-colored root showed not significant difference by drainage class and shade materials. Contents of panaxatriol ginsenoside (Rg1, Re and Rf) were decreased in PDC, while it of panaxadiol ginsenoside (Rb1, Rc and Rd) were increased in IDC. Total ginsenoside contents of IDC was distinctly higher than that of PDC, and BPSS showed the highest contents among three shade materials regardless of poorly and imperfectly drainage class.

• Journal of Life Science
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• v.24 no.10
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• pp.1092-1101
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• 2014

In this study, the distribution patterns of Quercus mongolica and Q. serrata in Korea were investigated, and the possibility of introgressive hybridization and gene flow between Q. mongolica and Q. serrata in Mt. Seorak was inferred by flavonoid analyses. The most critical factor in the vertical and horizontal distribution patterns of Q. mongolica and Q. serrata was the temperature, in accordance with latitude and altitude. The species showed a zonal distribution, with a Q. mongolica zone in the upper area and a Q. serrata zone in the lower area. In Mt. Seorak, Central Korea, the range of the vertical distribution of Q. mongolica was generally above an altitude of 100 m, whereas that of Q. serrata was an altitude of 0-400 m (-500) and rarely above an altitude of 500 m. However, in Mt. Jiri, Southern Korea, Q. serrata was found up to an altitude of 1,000~1,200 m, whereas the frequency of Q. mongolica was reduced at lower elevations and the species was rare below an altitude of 300 m, although pure stands were found on higher mountain slopes above an altitude of 1,200 m. The altitudinal distribution of the two species overlapped, where the two species occurred together. The leaf flavonoid constituents of thirty-four individuals of Q. mongolica and Q. serrata in Mt. Seorak and Mt. Jiri, Korea were examined. Twenty-four flavonoid compounds were isolated and identified. These were glycosylated derivatives of flavonols kaempferol, quercetin, isorhamnetin, myricetin. Five compounds among the flavonoid compounds were acylated. Kaempferol 3-O-glucoside, quercetin 3-O-glucoside, quercetin 3-O-galactoside, and its acylated compounds were major constituents and present in all individuals. Quercus mongolica is distinguished from Q. serrata by the presence of quercetin 3-O-arabinosylglucoside, a high concentration of three acylated compounds (kaempferol 3-O-glucoside, quercetin 3-O-glucoside, and quercetin 3-O-galactoside), and a relatively low concentration or lack of rhamnosyl flavonol compounds. Intraspecific variations, however, were found in the flavonoid profiles of Q. mongolica and Q. serrata, and the flavonoid profiles of individuals belonging to the two species in a hybrid zone (sympatric zone) tended to be similar, qualitatively and quantitatively. These findings strongly suggest that gene exchange or gene flow occurs through introgressive hybridization between Q. mongolica and Q. serrata in Mt. Seorak.

• Journal of Bio-Environment Control
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• v.25 no.2
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• pp.111-117
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• 2016

The objective of this study was to analyze the microclimate and the growth of tomato and lettuce in the greenhouses covered with spectrum conversion films using different phosphor particles sizes. Two spectrum conversion films using phosphor particles larger than $10{\mu}m$ (Micro-film) and smaller than 500 nm (Nano-film) in radius, and poly-ethylene (PE) film were used in double-layered greenhouses as outer coverings. PE films were used as inner coverings in all the greenhouses. Thickness of the films for inner and outer coverings was 0.06 mm. Tensile strength, elongation, and tearing resistance of the Micro- and Nano-films were not different from those of the PE film. Transmittances at a wavelength of 300-1100 nm were a little higher at the Micro-film and lower at the Nano-film than that of the PE film, respectively. Air temperatures at the Micro- and Nano-films were over $2^{\circ}C$ higher than at the PE film, but no significant difference was observed between the two light conversion films. The soil temperature at the Nano-film was $1.5^{\circ}C$ and $3^{\circ}C$ higher than at the Micro- and PE films, respectively. The yields of tomato at the Micro- and Nano-films were 12% and 14% higher than at the PE film, but no significant difference was observed between the two spectrum conversion films. The total soluble solid showed no significant differences among all the films. The yields of lettuces at the Micro- and Nano-films were 27% and 59% higher than at the PE film. Hunter's red (a) value of the lettuce leaf was the highest at the Nano-film. In this experiment, tomatoes requiring high irradiation were better at the Nano film, while lettuce requiring low irradiation better at the Micro film.