• Journal of Sericultural and Entomological Science
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• v.25 no.1
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• pp.1-20
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• 1983

It has been known that the insect molting hormone and its analogues exist also in plant kingdom and their concentration has been found to be about 0.1~2.0% of dry matter, which is equivalent to $10^3{\sim}10^5$ times of those in insects. This study was carried out; 1) to isolate the phytoecdysones from Korean Achyranthes radix and characterize their physico-chemical properties. 2) to investigate the biological activity of this phytoecdysone on Bombyx mori larvae. The resuls were summarized as follows; 1. The extraction method of phytoecdysones was optimized by three consecutive reflux for 1hr using 200g of dried and milled radix per 1l methanol. 2. The purification from the crude extract was made by a series of steps such as precipitation of gum-type polymer with n-Butyl acetate, adsorption on technical grade silica and chromatography with neutral alumina. The conditions of each step were optimized and the resulting crude crystal was about 500mg per kg dry radix. 3. The crude crystal from the cultivated Achyranthes(Achyranthes japonia) contained ecdysterone (20-hydroxyecdysone) and inokosterone in the proportion of one to one. In order to separate these, a series of processes such as acetylation, separation by alumina column chromatography deacetylation by alcoholysis, deionization and crystallization were introduced and optimized 125mg of ecdysterone and 18mg of inokosterone per kg dry radix were thus obtained. 4. The wild Achyranthes (Achyranthes obtusifolia) radix was found to contain the ecdysterone only. A 285mg of ecdysterone was crystallized per kg dry radix. 5. Isolated ecdysterone, inodosterone and acetylated compounds were characterized by IR., UV., NMR spectroscopy, mp, TLC and densitometry. 6. Ligation experiment was undertaken to confirm the biological activity of the purified ecdysterone; the ecdysterone could induce larval-pupal metamorphosis in the ligated abdomen of 4th instar larvae injecting 0.5~1.0${\mu}g$. 7. By ecdysterone feeding experiment using artificial diet, it was elucidated that the critical time of feeding would be the first half of each instar resulting in increased weight of silk layer. 8. The ecdysterone was fed to 5th instar silkworm at the level of 1, 2, 3, 5ppm of dry feed of artificial diet containing 5% mulberry leaves for 72hrs. At 2ppm of the concentration. body weight and silk layer weight were arrived at maximum. But at higher concentrations body weight and silk layer weight decreased than the control group. At 2ppm of the concentration, body weight was increased by 12.5%. 9. Feeding 2ppm of ecdysterone at the later half of 5th instar, the duration of larvae was shortened.

• Journal of Bio-Environment Control
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• v.8 no.1
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• pp.19-29
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• 1999

This experiment was conducted to compare with the growth and fruit quality of Citrullus lanatus cv. Mudeungsan and Citrullus vulgaris cv. Dalgona grown in fertigation and soilless culture. Seeds were sown on April 16 and transplanted on April 24, 1998. Cultural systems used in fertigation and soilless culture beds using mixed substrate, coir dust (50%) and perlite (50%). In the plot of fertigation system, the number of leaves of cv. Dalgona were increased more than that of cv Mudeungsan, but leaf area shown inversed trend. Plant growth shown greater in soilless culture than those of fertigation culture. In regardless of cultural systems, soluble solid content in fruit was higher in the cv. Dalgona than that of cv. Mudeungsan, but fruit fresh weight was greater in cv. Mudeungsan compare to the cv Dalgona. Nitrate content in petiole sap of watermelon in regardless of cultivars and cultural systems was 11.4∼13.4mg/gFW on 15 days after transplanting, and then increased to 17.1∼20.6mg/gFW on the fruit growth stage. Phosphorous content was 3.7∼5.7mg/gFW in the early growth stage while decreased to 0.6∼1.1mg/gFW from maturing stage to harvesting stage. Potassium content was increased to 5.8∼6.6mg/gFW in the early growth stage while decreased to 4.0∼4.8mg/gFW from pollination stage to harvesting stage. Calcium content in spa petiole of watermelon was higher in soilless culture as 3.4∼4.1mg/gFW than 2.5∼3.5mg/gFW of fertigation culture, but calcium content in fertigation culture during maturing stage was higher than that of soilless culture. The tendency of magnesium uptake was higher in fertigation culture than that of soilless culture, and was similarly absorbed in the range of 0.9∼1.3mg/gFW in regardless of cultural method after pollination. It was demonstrated that cv. Mudeungsan can be adapted to soilless culture and improved the fruit quality. Consequently, hydroponic possibility for year round culture in the greenhouse was recognized.

• Journal of Bio-Environment Control
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• v.20 no.1
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• pp.27-32
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• 2011

This study was carried out to investigate characteristics of new garlic cultivar 'Alkae' and to identify the effect of scape removal on bulb characteristics and growth of garlic cultivar 'Alkae' and 'Namdo'. Bolting time and harvesting time were earlier about 20 days in 'Alkae' than those in 'Namdo'. 'Alkae' was inferior to 'Namdo' in top growth as plant height, number of leaves, leaf area, SPAD value, diameter of leaf sheath, and so on. but root developing was better in 'Alkae'. Bulb weight of' Alkae' was 17% more than that of 'Namdo', harvested on proper time. The ratio of bulb weight over 40 g was almost double in 'Namdo' as 48% with 'Alkae' as 25%. Occurrence of bulb cracking was more considerable in 'Alkae' and the number of clove per bulb was 1.9 more in 'Alkae' than 'Namdo', but the ratio of bulb rot during storage was higher in 'Namdo' than 'Alkae'. In treatments of scape removal, SPAD value did not show any difference between two cultivars. Leaf dryness was earlier and harder than control and leaf area showed the same tendency as leaf dryness, and there were no significant differences among the methods of scape removal. The bulb weight and the ratio of bulb weight over 40 g at 50 days after the harvest of 'Alkae', 'Namdo' were more 10%, 12% and 27%, 44% in scape removal treatment than control. and there were no significant differences among the methods of scape removal. So, scape removal was very effective to increase large bulb production in the two garlic cultivals and the effect was higher in 'Namdo' than 'Alkae'. The ratio of bulb cracking and the occurrence of bulb rot were almost same in with the scape removal and non removal groups And also there were no significant differences among the methods of scape removal.

• Korean Journal of Organic Agriculture
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• v.10 no.1
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• pp.75-86
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• 2002

This study was conducted to investigate the effects of pig manure composting using starch pulp m growth and yield characteristics of potato cropping. Four treatments ; No compost, 1 : 1 : 0, 1 : 0.75 : 0.25 and 1 : 0.5 : 0.5 the mixing ratio of pig manure, saw dust, and dehydrated starch pulp and composting by Piling and blowing methods. Plant heights in first growth stage were higher for the treatment of saw dust compost and starch pulp compost than the treatment of chemical fertilizer, but after the stage, there were no significant difference among treatments. The number of stolons were met for 10.9 in 1 : 0.5 : 0.5 treatment, following 1 : 0.75 : 0.25 and 1 : 1 : 0. On the other hand, tuber diameter and top dry matter weight tended to be larger for manure treatment than no treatment but there was no significant difference. Total number of tubers were largest for 1 : 0.5 : 0.5, and those for 1 : 1 : 0 and 1 : 0.75 : 0.25 were similar. Tuber yields of not more than 80g tended to be different, but those of between 81g and 120g and more than 120g were apparently larger for the compost treatment than no treatment. The ratio of marketable tubers appeared large to be about 86% for 1 : 0.75 : 0.25 and 1 : 0.5 : 0.5 treatments. Ratio of infected common scab on potato tubers tended to be highest for 1 : 0.5 0.5 but there were no statistical significance. However, when compost was made by mixing starch pulp in future, the solutions to the occurrence of infected common scab must be considered, The contents of N. P, K and Ca in leaves were larger for the compost treatment than no treatment, but no significant difference was observed, Accordingly, the effects of treating starch pulp compost on growth and yield characteristics of potato cropping were more affirmative than those of saw dust compost.

• Korean Journal of Soil Science and Fertilizer
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• v.2 no.1
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• pp.31-38
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• 1969

This experiment was carried out to determine the effect of different levels of phosphate and potash firtilizers applied on yields and quality of leaf tobacco. It was done at all varying levels of phosphate and potassium fertilizers $S_0$ (non-fertilizer plot);N:P:K=0:0:0 (Kg/10a) $S_1$ (1/2 amount plot);N:P:K=10:7.5:10 (Kg/10a) $S_2$ (standard plot);N:P:K=10:15:20 (Kg/10a) $S_3$ (1.5 times plot);N:P:K=10:22.5:30(Kg/10a) $S_4$ (2.0times plot);N:P:K==10:30:40 (Kg/10a) Urea was applied as nitrogen, triple superphosphate as phosphate, potassium sulfate as potash source. The total amount of fertilizers was applied as basal dressing per one plant. This experiment was carried out by using randomized block design with 3 replication. The results obtained in terms of yields and quality are summarized as follows. 1. By increasing the amounts of phosphate and potassium fertilizers, growing status of the largest leaf length, the largest leaf width and stem size of tobacco increased in the order of $S_4>S_3>S_2>S_1>S_0$. 2. By increasing the amount of phosphate and potassium fertilizers, yield was increased in the order of $S_4>S_3>S_2>S_1>S_0$, This increase showed generally high significance among various levels of treatments. 3. The regressive equation was derived from the relationship between treatment levels and tobacco leaf yield. The most desirable treatment level for the maximum yield was estimated as the 2.87 times as much as the treatment level of phosphate and potasium fertilizers of standard plot. 4. By increased application of phosphate and potash fertilizers, the contents of $P_2O_5$ and $K_2O$ in the tobacco leaf became greater while the content of nicotine was decreased. Thus, a negative correlation between fertilizer application and nicotine content has been observed.

• Korean Journal of Environmental Agriculture
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• v.25 no.1
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• pp.47-57
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• 2006

This study was carried out to select the Eco-tree for successful phytoremediation of abandoned metalliferous mines. We examined vegetation and heavy metal concentrations of woody plants in abandoned mining areas, and also conducted seed germination and seedling growth experiment on contaminated soils from Gahak and Geumjeong mines. Pinus densiflora, Robinia pseudoacacia, Lespedeza bicolor and Alnus japonica showed high frequency in the survey areas and had high heavy metal concentrations compared to other species. Heavy metal concentrations were higher in roots than in leaves and stems. The seed germination rate was in the order of P. densiflora, L. bicolor, R. pseudoacacia, and Alnus japonica from the incubactor and greenhouse experiment. In the incubator experiment germination rate was highest in the control soil for P. densiflora and A. japonica. Germination rate of P. densiflora was highest on the 100% contaminated soil for Gahak mine while germination rate decreased with increased percentage of contaminated soil for Geumjeong mine. In the greenhouse experiment germination rate was lowest on the 40% contaminated soil for Gahak mine while germination rate was lowest on the 20% contaminated soil for Geumjeong mine and increased with increased percentage of contaminated soil. Shoot growth was highest for L. bicolor while root growth was highest for R. pseudoacacia except for 20% contaminated soil in Geumjeong mine.

• Journal of Applied Biological Chemistry
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• v.54 no.4
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• pp.258-264
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• 2011

The Korean edible mountainous vegetable, byeongpungssam, Cacalia firma Komar. (CFK) is a wild plant found in the intermountain areas in Korea. The aim of this study was to investigate its free radical scavenging activity using 1,1-diphenyl-2-picryl-hydrazyl, 2,2-azinobis(3-ethylbenozothiazoline- 6-sulfonic acid) diammonium salt, ferric reducing/antioxidant power assays, an electron spin resonance spectroscopy. We also examined its protective effect against oxidative DNA damage using agarose electrophoresis of ethanol extract of CFK. The protective activity of the extract against the DNA damage induced by HO${\cdot}$ radicals was compared to epicatechin, ascorbic acid and trolox as reference antioxidant compounds. Total phenolic content in the extract was determined spectrometrically according to the Folin-Ciocalteu procedure and calculated as gallic acid equivalents. Total polyphenolic content of the extract was measured in the leaves ($161.53{\pm}1.07{\mu}g/g$) and shoot ($142.45{\pm}0.56{\mu}g/g$). The antioxidant potential of the extracts against some radicals and DNA damage by HO${\cdot}$ radicals showed over 60%, respectively.

• Korean Journal of Weed Science
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• v.17 no.1
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• pp.31-43
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• 1997

This study was carried out to investigate classfication of weedy rice (Oryza sativa) based on isozymes esterase and peroxidase, growth and developmental difference of weedy rices and rices grown under dry and water condition, and weedy rice control and tolerant difference of weedy rices in various herbicides using weedy rices collected from thirteen strains of Chonnam, one Chonbuk, two Kyeongki and two rice cultivars. 1. The collected weedy rices were classified into three groups based on isozyme esterase and peroxidase using polyacrylamide gel electrophoresis(PAGE) method. The classified groups were not same each other. 2. Plant height was taller in collected weedy rices than rice cultivars at 18 days after seeding under dry and water conditions, but number of leaves, shoot fresh weight, root fresh weight and root length were not significantly different between collected weedy rices and rice cultivars. In addition, growths of collected weedy rices were greater in dry- than water-condition. 3. After thiobencarb(S-4-chlorobenzyl diethythiocarbamate), molinate(S-ethyl hexahydro-1H-azepine-1-carbothioate) and oxadiazon(5-tert-butyl-3(2,4-dichloro-5-isopropoxyphenyl)-1,3,4-oxadiazol-2-one) were applied at 6 days before seeding, the weedy rices controlled 100% by thiobencarb at 2.1kg ai/ha and 024kg ai/ha oxadiazon treatment but controlled 26% to 67% by molinate at 6.5kg ai/ha. Rice due to the herbicides was injured severely(25% to 100%) in flood condition at time of rice seeding after oxadiazon at 0.48kg ai/ha and 2.1kg ai/ha thiobencarb application, except for molinate which injured rice slightly(4% to 13%) in drain condition. The collected weedy rices to all experimented herbicides showed slight intraspecific variations. The intraspecific variations of weedy rices decreased in the order of thiobencarb>molinate>oxadiazon.

• Korean Journal of Medicinal Crop Science
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• v.7 no.2
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• pp.101-106
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• 1999

These studies were carried out to investigate the quality of green tea processed by different 1st-pan-firing time and to select the best conditions of green tea processing. The results were as follows. At harvesting tea plant leaf, tea plants had 4 leaves, each leaf size was $6.4cm\;{\times}\;2.4cm$, and weight of 100 buds was 40.2g. The content of moisture of green tea was decreased with the prolongation of 1st-pan-firing time, and the yield of green tea at 10 min. pan-firing time was the highest value of 20.12%. After processing green tea, 1st 10 min. pan-fired one had much more contents of total nitrogen(TN 5.41%) and total amino acid(T.A.A; 3,282mg/100g) and less content of tannin(13.22%) and caffeine(1.64%) than the other treatments. The content of chlorophyll and vitamin C went down with the extension of 1st pan-firing period. Sixteen kinds of free amino acid including theanine as a good taste component of green tea were isolated and measured by HPLC. T.A.A contents were in the range of $2,447{\sim}3,192mg/100g$ and among various pan-firing methods, 10 min. 1st pan-fired one had the highest content of T.A.A. The taste-determinants such as theanine, aspartic acid, serine, glutamic acid and arginine in green tea liquor, occupied as much as $89.4{\sim}90.0%$ of T.A.A.s. Among these, theanine was more than 50%, Lightness and yellowness of green tea were increased with delay of pan-firing time, while green color appeared to be more distinct at 10 min. 1st pan -firing time than other treatments. Besides, it gained the highest score of sensory evaluation among them. These above results suggested that 10 min. pan-fired green tea was considered to be the best level as pan-firing time of green tea processing.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.2
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• pp.62-68
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• 2018

This study investigated the effect of light intensity on the removal of particulate matter by Dieffenbachia amoena 'Marianne' and Spathiphyllum spp.. An acrylic chamber ($600{\times}800{\times}1200mm$, $L{\times}W{\times}H$) modeled as an indoor space and a green bio-filter ($495{\times}495{\times}1000mm$, $L{\times}W{\times}H$) as an air purification device were made of acrylic. The removal of particulate matter PM10 and PM1, the photosynthetic rate, stomatal conductance, and number of stomata of Dieffenbachia amoena 'Marianne' and Spathiphyllum spp. were measured according to three different levels of light intensity (0, 30 and $60{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}PPFD$). Regarding the length of time taken for PM10 to reach $1{\mu}g$, the Dieffenbachia amoena 'Marianne' showed a significant difference according to the presence or absence of light, and there was no significant difference shown between light intensity of 30 and $60{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}PPFD$. As for the Spathiphyllum spp., there was no significant difference between 0 and $30{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}PPFD$, while a significant difference was shown at $60{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}PPFD$. After 90 minutes, the PM1, PM10, and $CO_2$ residuals of the Spathiphyllum spp. were lowest at $60{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}PPFD$. The remaining amount of PM1 and PM10 was lower with the Spathiphyllum spp. than with the Dieffenbachia amoena 'Marianne', even at $0{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}PPFD$. With both plants, the higher the light intensity, the higher the photosynthetic rate, while the stomatal conductance did not show any significant difference. Spathiphyllum spp. showed a higher photosynthetic rate and stomatal conductance and a greater number of stomata than Dieffenbachia amoena 'Marianne', and stomata were observed in both the front and back sides of the leaves. The air purification effect of Spathiphyllum spp. is considered to be better than Dieffenbachia amoena 'Marianne' at the same light intensity due to such plant characteristics. Therefore, in order to select effective indoor plants for the removal of particulate contamination in an indoor space, the characteristics of plants such as the photosynthetic rate and the number and arrangement of stomata according to indoor light intensity should be considered.