• Applied Biological Chemistry
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• v.11
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• pp.151-166
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• 1969

I. Fffects of nitrogen supplying level and culture condition on the top growth aod tubers formation of Ipomoea Batatas. 1) The low level nitrogen (A plot) 3 Milliequivalent per liter of nutrient solution stimulated tuber formation while the high level nitrogen ($B_1\;and\;B_2$ plot) of 10 milliequivalent per liter failed to form tuber though fibrous roots were seen much activated. The suppressive effect of nitrogen on tuber formation in presumed to result from the direct suppressive effect of nitrogen or a certain biocatalystic effect rather than from any indirect effect through the stimulation to growth of tops or the competition with carbohydrates. 2) The addition of milligram urea to nutrient solution stimulated the growth and increased fresh weight and dry weight of the aerial part while suppressed, a little, plant length. 3) The water culture method, which this experiment newly adopted, stimulated plant growth more than the gravel Culture method. And the treatment of low level nitrogen (A plot) in this water culture also saw a considerable degree of tuber formation, as in the case of gravel culture. 4) The foliar application of growth retardant B-nine suppressed the plant length only, with no other recognizable effect. II. Fffects of urea supplying level on the growth of IPOMOEA BATATAS. 1) The higher level of urea which was absorbed tby roots through nutrient solution suppressed top growth, such as plant length, number of leaves and fresh weight. And this can be attributed to the direct absorption of urea which was not ammonificated. 2) Although the higher level of nitrate nitrogen (B plot) made no tuber formation in previous experiment (Report-1), the higher level of urea nitrogen (A plot) made tuber formation possible in this experiment. The ratio of tuber to top was, however, less in higher level of urea than in lower level of urea, and the suppressing effect was larger on tuber than on top. 3) The foliar application of urea stimulated top growth while the higher level of urea absorbed by roots suppressed it, though the amounts of urea supplied in two experiments were same. Ratio of top to roots was larger in foliar application of urea (C plot) and less in root absorption of urea both of higher (B plot) and lower urea levels (A plot). III. Fffects of growth retardant etc. on the growth of IPOMOEA BATATAS in relation to urea application. 1) B-nine (N-dimethyl amino-succinamic acid) is recognized as a growth retardant, suppressed the plant length irrespective of urea levels. The treatment of gibberellin stimulated distinctly plant length, and the combined treatment of gibberellin and B-nine recovered completely the plant length which had been suppressed by B-nine. 2) B-nine increased fresh weight, especially, fresh weight of top both in lower and higher level of The degree of fresh weight increase varied according to concentrations of B-nine, of which the 0.15% of B-nine ($B_1$ plot) was the effective in higher level of urea. The effect of B-nine for increasing fresh weight was the largest in top next in tuber, and the least in fibrous roots. The ratio of fibrous roots to top was always decreased by B-nine application, which the ratio of tuber to top was contrary increased by B-nine in higher level of urea though decreased in lower level of urea. 3) Gibberellin treatment also increased fresh weight but the combined treatment ($B_3$+GA plot) of gibberellin and B-nine was even more effective than any of single treatments. Gibberellin and B-nine proved to be synergistic with fresh weight while reverse with plant length. 4) Considerable influences were abserved mainly in the length of plants and their fresh weight after B-nine treatment. So that B-nine may be reguraded as a metabolic controller rather than as an antimetabolite. 5) The surpressed growth of plants cause by higher level of urea was normalized by B-nine treatment. This fact suggested a further study on the applicability for practical use.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.237-243
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• 2013

Pesticides were sprayed on perilla leaf and leafy lettuce in a greenhouse and the reduction rate of pesticide residues on each vegetable by washing were tested. The reduction rate of pesticide residues by washing for 30 sec~3 min on perilla leaf were 3~63% in tap water, 2~58% in salt water, 6~74% in green tea water, and 8~86% in detergent solution. The detergent solution only showed significant difference in reduction rates compared to the tab water washing. Considering reduction effects of the washing duration, it was showed that the reduction rates were a pattern of inclining as the duration of washing process increased, but there was no significant difference in the reduction rates except the reduction rates between washing in the detergent solution for 1 min and 3 min. Comparing washing in flowing tab water and in stagnant tab water with leafy lettuce, the reduction rate by one time washing were 8~68% in flowing tab water and 7~64% in stagnant tab water. The water and the time used in this experiment were 17.5 L, 2.9 min with flowing tab water and 4 L, 1 min with stagnant tab water. The reduction rate by 3 times washing in stagnant tab water were 16.5~76.6%, and the water and the time used were 12 L, 3 min. Therefore, when the water and the time used to wash vegetables were considered, washing two or three times in stagnant tab water could be more effective than washing one time in flowing tab water.

• Microbiology and Biotechnology Letters
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• v.37 no.3
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• pp.280-286
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• 2009

To investigate anti-phytopathogenic fungal activity of Coptis chinensis, the methanol extract and its organic solvent fractions were prepared. Using the extract and the fractions, in-vitro spore-germination inhibition and mycelial-growth inhibition activities were evaluated against Colletotrichum gloeosporioides, Phytohpthora capsici, Pyricularia grisea, Rhizoctonia solani, Botryosphaeri dothidea, Glomerella cingulata, respectively. Treatment of the methanol extract (500 mg/mL) into the spore of phytopathogenic fungi completely inhibited germinations for 5 days, except B. dothidea, and showed strong antifungal activities against P. grisea and B. cinerea, and antioomycetes activity against P. capsici. The minimal growth inhibition concentrations of the methanol extract against P. grisea, B. cinerea and P. capsici were 300, 300, and 500 mg/mL, respectively. For practical application of C. chinensis in red-pepper field, the hot-water extract (1,000 mg/mL) was prepared in commercial facility, after evaluation of heat stability and solvent-extraction yields of antifungal substances. The 3-times leaf-spray of the extract from June to August, 2008 did not show any deleterious effect to red-pepper. In fact, the leaf-spray promoted plant growth including leaf, root and fruit. The average weight and rind of each fruit were increased to 119% and 117% comparison to those of without treatments. Our results suggest that C. chinensis is a useful source for control of red-pepper diseases and plant growth.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.6
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• pp.29-36
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• 2008

This study examined the de-icing agents' stresses on Pinus strobus and Pinus thunbergii by chlorophyll fluorescence analysis. The assumption of this study was that photosynthetic efficiency was changed by de-icing agents applied onto highways in winter by altering the concentration of the de-icier, types of de-icer and leaf surface coating liquid application. The practical purpose of this study was to investigate the de-icing gents stresses on Pinus strobus by the highway area where de-icing agents were used frequently and to discover out minimizing stratages to prevent further damages. or this simulation study, a sample plot was established in Bogae-myeon, Anseong, Gyeonggi-do and Pinus strobus and Pinus thunbergii were planted for the examination in April, 2005. Five types of de-icing agents - NaCl, $CaCl_2$, T product(NS40:low cWoride de-icer type), NaCl+$CaCl_2$ and T product+$CaCl_2$ - were selected and the their concentration was altered to 0%, 5%, and 9%. Five types of de-icing agents were applied to both trees treated by a leaf surface coating liquid and trees not treated by leaf surface coating liquid. For the fluorescence analysis, the leaf surface coating liquid, which was diluted by 10 times, was sprkinkled onto the two tree species three days prior to gathering samples. Sample leaves from the two tree species were gathered at 10 o'clock in the morning of mid-August, 2006 and brought to the laboratory within three hours to be dipped in different concentrations (0%, 5%, or 9%) of the five de-icing agents for two minutes. Then the eaves were placed on the filter paper dipped in each solution on a petri dish, sealed with polyethylene film and kept in a growth chamber at $22^{\circ}C$ for 72 hours. Out of the growth chamber, the leaves were treated with a chorophyll fluorescence reaction analyzer for 30 minutes to measure the initial light acceptance rate(Fo), maximum light acceptance ate(Fv/Fm), light acceptance usage(F' q/F' m) and optical electron delivery coefficient(qP). As a result, Pinus strobus' initial light acceptance rate(Fo) decreased as T product and NaCl increased in concentration, and $Cal_2$ did not reduce much with the eaf surface coating liquid application. Maximum light acceptance rate(Fv/Fm) and light acceptance usage(F' q/F' m) decreased sharply as T product and NaCl increased in concentration and NaCl+$CaCl_2$ and T product+$CaCl_2$ did not reduce much with leaf surface coating liquid application. Optical electrons delivery coefficient (qP) decreased as T product increased in concentration on trees without the leaf surface coating liquid application and all other de-icing agents did not show much reduction. As for Pinus thunbergii, the initial light acceptance rate(Fo) decreased as T product increased in concentration, but the maximum light acceptance rate(Fv/Fm) was not reduced much by changes in concentration. light acceptance usage(F' q/F' m) decreased as NaCl increased in concentration and optical electron delivery coefficient(qP) decreased as NaCl increased in concentration in both with and without leaf surface coating liquid application. In conclusion, it was possible to plant Pinus strobus if spraying leaf surface coating liquid or cleaning deicing salt to prevent the damage caused by deicing agents was more economical than replacing the trees. If not, it was better to plant Pinus thunbergii. Another way to decrease the deicing gents stresses of landscape plants would be planting the trees further away from the roads even though it might take longer period to display its planting functions.

• Journal of Korean Society of Forest Science
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• v.47 no.1
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• pp.1-15
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• 1980

The occurrence of witches' broom of Rhus javanica was first noticed in Korea by the author in 1979. Subsequently, studies were made on the symptomatology, etiology, and transmission of the disease, as well as the effect of some antibiotics on the disease development. The results of these studies are summarized as follows: 1. Symptoms of the infected plant were characterized by dwarfing of the tree accompanied by yellowing and brooming of the foliage. 2. Electron microscopy of witches' broom diseased Rhus javanica plant revealed the occurrence of numerous mycoplasma-like organisms (MLO's) in the phloem tissue cells (sieve tube elements and phloem parenchyma cells) of the rachis and midribs of infected leaves. 3. The MLO's were bounded by a single unit membrane and contained ribosome-like granules and strands presumed to be DNA. It also appears that the MLO multiply possibly by budding as well as binary and plurinary fission. 4. In the midrib of healthy leaves, vascular bundles were collaterally discontinuous. In the diseased leaves, however, xylems were connected to each other and phloem cells showed an atrophy. Granules, which were prominent in the normal abaxial epidermis, were not observed in the peidermis of diseased leaves. 5. Electron microscopy revealed crystals or osmopholic granules in the phloem parenchyma cells, and that normal stacks of grana were not developed in the chloroplasts of infected levels. 6. The disease was experimentally transmitted by grafting. Budding was more effective than crown grafting for transmitting the disease. The disease has been transmitted by grafting even when complete union of stocks and scions has not taken place. The disease agent was not transmitted by sap inoculation. Insect transmission has not been confirmed. 7. Dipping the roots of infected plants into the 500 ppm and 1,000 solutions of either tetracycline HCI or oxytetracycline, HCI was more effective on temporary remision of the symptoms than spraying the 100 ppm and 200 ppm solutions of the same antibiotics. A greater effect was achieved through dipping into 1,000 ppm than into 500 ppm.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.4
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• pp.518-524
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• 1995

In this study physicochemical characteristics such as crude lipid, crude protein and total sugar contents have been analyzed with samples taken at different developing stages and growing sites, Bongsan-ri(steam-roasted green tea) and Buchun-ri(roasted green tea) area. Leaf area of new leaf was larger in Buchun-ri(7.23cm$^2$) than in Bongsan-ri(6.93cm$^2$). Variation of leaf area by the developing stages was the largest at between stage II (May 5) and stage III(May 18). Dry matters ratio of tea leaf were 26.3% in Bongsan-ri and 26.6% in Buchun-ri. Water content, ash, water-soluble matters, total sugar content of green tea sampled in Bongsan-ri and Buchun-ri were 5.6, 6.1, 33.1, 4.6 and 6.2, 5.8, 35.2, 2.8%, respectivley. Crude lipid, total nitrogen and water-soluble protein, inorganic matters content of green tea sampled in Bongsan-ri and Buchun-ri were 2.8, 5.1, 1.1, 2.56 and 2.2, 5.7, 1.0, 2.34%, respectively. At the later developing stages crude lipid, total sugar contents were increased, whereas total nitrogen had low content. Vitamin C, Vitamin E and Vitamin A content of green tea produced in Bongsan-ri and Buchun-ri area were 413mg%, 71.8mg%, 32.15IU and 311mg%, 52.3mg%, 25.68IU, respectively. Vitamin C and Vitamin E content were increased toward the later sampling stages. Water-soluble matters and water-soluble protein content of green tea prepared by the steam-roasted method and the roasted method were increased by 0.11, 0.13 and 0.09, 0.08%, respectively, compared to unroasted check. Crude lipid content of green tea prepared by the steam-roasted method and the roasted method were decreased by 0.13 and 0.24%, respectively. Total nitrogen content of green tea prepared by the steam-roasted method and the roasted method was changed 0.019 and 0.036%, respectively and total nitrogen content showed minute different between two methods.

• Applied Biological Chemistry
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• v.8
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• pp.87-93
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• 1967

1) For the micro-analysis of mercury in plant materials, the method of Furutani was shown to be the simplest and most efficient way and the recovery of the assay was about 98%. 2) When the rice grain was soaked in 1/1000 diluted solution of organo-mercury fungicide for 8 hours at the end of March, the amounts of mercury residues in the brown rice and unhulled rice were 8.8 to $9.5\;{\mu}g/g$ seeds and 10.1 to $10.7\;{\mu}g/g$ seeds, respectively. 3) By washing the treated rice seeds with running water for three days, tile residual mercury concentration was reduced to 1/4 to 1/5; thus the mercury residues were 1.86 to $1.92\;{\mu}g/g$ for brown rice and 1.96 to $2.93\;{\mu}g/g$ for unhulled rice. 4) The residual mercury was present more in the unhulled rice than in the brown rice, either before or after washing of the treated seeds. 5) Among the different rice varieties, no difference was observed in mercury residues by seed treatment and washing.