• Journal of Radiation Protection and Research
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• v.25 no.1
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• pp.11-19
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• 2000

The sensitivity analysis of input parameters for a dynamic food chain model DYNACON was conducted as a function of deposition date for the long-lived radionuclides $(^{137}Cs,\;^{90}Sr)$. Also, the influence of input parameters for the short and long-terms contamination of selected foodstuffs (cereals, leafy vegetables, milk) was investigated. The input parameters were sampled using the LHS technique, and their sensitivity indices represented as PRCC. The sensitivity index was strongly dependent on contamination period as well as deposition date. In case of deposition during the growing stages of plants, the input parameters associated with contamination by foliar absorption were relatively important in long-term contamination as well as short-term contamination. They were also important in short-term contamination in case of deposition during the non-growing stages. In long-term contamination, the influence of input parameters associated with foliar absorption decreased, while the influence of input parameters associated with root uptake increased. These phenomena were more remarkable in case of the deposition of non-growing stages than growing stages, and in case of $^{90}Sr$ deposition than $^{137}Cs$ deposition. In case of deposition during growing stages of pasture, the input parameters associated with the characteristics of cattle such as feed-milk transfer factor and daily intake rate of cattle were relatively important in contamination of milk.

• Korean Journal of Weed Science
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• v.14 no.4
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• pp.280-290
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• 1994

The germination and the nutrient culture tests in the growth chamber and pot experiment under two types of soil conditions were conducted to determine the selectivity of oxyfluorfen and chlormethoxynil in crops and weeds and for characterization of selective mode of action, the absorption study was also conducted with different absorption methods and application time using $^{14}C$-oxyfluorfen. Oxyfluorfen showed more growth inhibitory effects than chlormethoxynil. In the nutrient culture test, rice growth was greatly inhibited at 2-leaf stage than at 4-leaf stage, and the shoot parts were more inhibited than the root parts. By preemergence application of both herbicides, higher growth inhibition was observed in sandy loam soil than in clay loam soil. Absorption and translocation of $^{14}C$-oxyfluorfen were higher by foliar application than by root treatment, and selectivity of crops and weed species may be explained partly by the amount of absorption.

• The Korean Journal of Pesticide Science
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• v.3 no.2
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• pp.19-28
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• 1999

To investigate the physiological and biochemical differences between susceptible and tolerant species of Echinochloa species to the foliar applied cyhalofop-butyl and pyribenzoxim herbicides, herbicidal response, the rate of absorption, translocation and metabolism were studied. Among 148 individuals of Echinochloa species collected from 41 sampling sites in Korea which were classified into 7 geographical regions, based on morphological characteristics of plant and seed type, 46 lines were used for further studies. From them, E. crus-galli var. praticola collected from Hwanggan and E. crus-galli var. crus-galli collected from Namyangju were selected as the most susceptible species to cyhalofop-butyl and pyribenzoxim, respectively. Meanwhile, E. oryzicola(from Cheju) and E. crus-galli var. crus-galli(from Asan) were selected as tolerant species to cyhalofop-butyl and pyribenzoxim, respectively. Application of radio-labelled herbicides on the 1st leaf to both susceptible and tolerant Echinochloa species exhibited that the applied $^{14}C$-Cyhalofop-butyl and $^{14}C$-pyribenzoxim were more easily absorbed and translocated into stem tissues than root. Absorption of $^{14}C$-Cyhalofop-butyl increased rapidly at 1 h after application and reached the maximum at 12 h after application. However, the absorption rate of $^{14}C$-pyribenzoxim was not changed. Two metabolites from cyhalofop-butyl-treated plants and one metabolite from pyribenzoxim-treated plants were separated by TLC. The amount of metabolite 1 in cyhalofop-butyl-treated tolerant species was significantly higher than that in the susceptible one, suggesting differences in detoxification ability between susceptible and tolerant species.

• Applied Biological Chemistry
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• v.9
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• pp.125-147
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• 1968

This experiment was carried out as a part of the studies on reasonable application of nitrogen in rice plant to determine: (I) Nitrogen absorption. and rooting of rice seedlings as affected by urea foliar application at late seedling stage (II) Effect of leaf prunning and foliar application of urea at late heading stage on the maturation and yield of rice (III) Effect of foliar application of urea and its time during the stage of ear formation on yield of rice plant. Results obtained are summarized as follows. Exp.I: Nitrogen absorption and rooting of rice seedlings as affected be urea foliar application at late seedling stage. 1 : The foliar application of urea plots$(T_{1},T_2)$ snowed mare N-content than non-urea foliar application plot(T0) at lane seedling stage, being significant among treatments and foliar application of urea seemed more effective in increasing the N-content of seedlings. and promoted root settlement and early growth alter the transplanting. 2 : The carbon contents of the plants of $T_1$, and $T_2$ at late seedling stage increased than T0, and the carbon contents. of $T_1$ and $T_2$ plots became higher in amount in proportion to the nitrogen absorption as compared with those of $T_0$. 3 : C/N ratio appeared significant among soil application plots($N_1, \;N_2$) and foliar application of urea plots ($T_1$, $T_2$ and $T_0$). C/N ratio was lower in case of increased amount of nitrogen. The higher contents of nitrogen and carbon and lower C/N ratio resulted in the increment of root numbers and root lengths. Exp.II: Effect of leaf prunning and foliar application of urea at late heading stage on the maturation and yield of rice. 1 : There was a highly significant decrease in the maturing rate by severe leaf prunning. In the mean time, significant increase in maturing rate was observed with urea foliar application and it was found the more frequent application the more effective for higher maturing rate with a moderate significance. A correlationship between the level of prunning and maturing rate was enumerated to 0.961 of correlation coefficient, which indicated an increased maturing rate by the increased number of remaining leaves. 2 : The 1.000 grain weight, grain weight and hulled rice yield increased by leaf prunning in order (plot a$A_1$, $A_3$, $A_2$ and $A_0$ were 89.8%, 89.4%, 87.8% and 87.5% respectively, showing the highest of rate in $A_1$ and $A_3$ in methods of ear fertilization and being highly significant between its treatment. 3 : 1000 grain weights were highly significant between time of application, showing a tendency of increase of weights with the time lagging until days before earings as that of maturing rates. High significance was recognized between methods of ear fertilization, showing the highest in $A_2$ 23.18 gr. 4 : Yields per $3.3m^2$ were not significant between time of ear fertilization, whereas were highly significant between methods of ear fertilization. Those of $A_1$, $A_3$, $A_2$ and $A_0$ were 1.486 kg, 1.491 kg, 1.381 kg and 1.328 kg, respectively, showing the highest in $A_1$ and $A_3$. 5 : Hulling ratios showed significant different between time of ear fertilization, showing the highest in $T_2$, whereas those of methods of ear fertilization were highly significant between its treatment, Those of $A_1$, $A_3$, $A_2$ and $A_0$ were 84.72%, 84.06%, 83.29%, and 82.56% respectively, showing the highest m $A_2$ and $A_3$ among others. 6 : Yields of hulled rice per $3.3m^2$ showed significant different between time of ear fertilization, showing the highest in $T_1$ 1.192 kg. Whereas, those were highly significant between methods of ear fertilization. Those of $A_1$, $A_3$, $A_2$ and $A_0$ were 1.259 kg, 1.254 kg, 1.149 kg and 1.095 kg, respectively, showing the highest in $A_1$ and $A_2$. 7 : Contents of nitrogen on rice plant increased in case of nitrogen application as ear fertilizer and showed that the case of urea foliar application was more effective than that of soil application, showing the increased nitrogen content of rice plant was accompanied by carbon content.

• Nuclear Engineering and Technology
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• v.15 no.2
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• pp.110-116
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• 1983

The absorption and translocation of strontium-90 by soybean plant, Glycine max, was studied by applying strontium-90 solution on the foliage or on the soil surface right after the first flowering time under greenhouse conditions. The results are summarized as follows. In the foliar application of strontium-90, only a small portion of the radioactivity was translocated to other parts of the plant and most of it remained in the applied leaves, which should cause soil contamination after falling. In the soil surface application of strontium-90, much of the radioactivity was absorbed through the root and translocated to stems and leaves by different patterns depending on the growth stage.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.4
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• pp.356-362
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• 1984

A field experiment was carried out to investigate the sulfur effects on yield, growth and nutritive qualities of soybean in the different fertilizer application methods. Ammonium sulfate and super-phosphate were applied to the soil with levels of 0, 2, 4, and 6Kg S/10a and potassium sulfate, ammonium sulfate and thiourea were applied by foliar application with 2KgS/10a. The results obtained were as follows; 1. Grain and dry matter yield of soybean were increased by the increase of sulfur application and sulfur application showed positive effect on yield components. 2. Sulfur application increased the sulfur content and decreased N/S ratio in grain of soybean. 3. Protein content was increased by raising sulfur application up to 4Kg S/10a. Sulfur application influenced on amino acid composition of soybean protein. Cysteine and methionine contents were increased by sulfur application. 4. Lipid content of soybean grain and inorganic ion absorption by soybean plant were not influenced significantly by sulfur application. 5. In application effects, there was no significant difference among sulfur fertilizers, but foliar application was more effective than soil application.

• Korean Journal of Environmental Agriculture
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• v.13 no.2
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• pp.175-182
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• 1994

The experiment was performed to investigate the effects of simulated acid rain of several pH levels (2.0, 3.0, 4.0, and 5.0) on growth, injury, pigment compositions and leaf surface morphology of the seedlings of Amaranthus tricolor L. by foliar application. The growth of the tops and roots was markedly retarded below pH 3.0 and speck spots appeared on the leaf. Seven different peaks were detected by the absorption spectra of pigments of the leaf. But cv. Early splendor did not show the peaks at 473nm and 535nm, and nor did cv. Tricolor show the peaks at 476nm and 546nm. The pigment composition of leaves was affected by strong acid rain. As pH levels decreased, chlorophyll content increased. Leaf surface was eroded by acid rain, and leaf surface tissues were broken down and collapsed at the lower pH levels.

• Journal of Radiation Protection and Research
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• v.43 no.2
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• pp.50-58
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• 2018

Background: In terms of the Level 3 probabilistic safety assessment (Level 3 PSA), ingestion of food that had been exposed to radioactive materials is important to assess the intermediate- and long-term radiological dose. Because the ingestion dose is considerably dependent upon the agricultural and dietary characteristics of each country, the reliability of the assessment results may become diminished if the characteristics of a foreign country are considered. Thus, this study intends to evaluate and analyze the ingestion dose of Korean during a severe accident by completely considering the available agricultural and dietary characteristics in Korea. Materials and Methods: This study uses COMIDA2, which is a program based on dynamic food chain model. It sets the parameters that are appropriate to Korean characteristics so that we can evaluate the inherent ingestion dose of Korean. The results were analyzed by considering the accident date and food category with regard to the $^{137}Cs$. Results and Discussion: The dose and contribution of the food category depicted distinctive differences based on the accident date. Particularly, the ingestion dose during the first and second years depicted a considerable difference by the accident date. However, after the third year, the effect of foliar absorption was negligible and exhibited a similar tendency along with the order of root uptake rate based on the food category. Conclusion: In this study, the agricultural and dietary characteristics of Korea were analyzed and evaluated the ingestion dose of Korean during a severe accident using COMIDA2. By considering the inherent characteristics of Korean, it can be determined that the results of this study will significantly contribute to the reliability of the Level 3 PSA.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.1
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• pp.68-78
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• 1997

Laboratory and greenhouse studies were conducted to determine differential sensitivities on absorption of $^{14}$ C-oxyfluorfen and the anatomical responses in wheat and barley to protoporphyrinogen oxidase-inhibiting herbicides [oxyfluorfen (2-chloro-1- (3-ethoxy -nitrophen-oxy)-4-(trifluoromethyl) benzene, acifluorfen(5-[2-chloro-4-(trifluoromethyl) phenoxy]-2-nitro-benzoic acid), bifenox(methyl-5-(2, 4-dichlorophenoxy)-2-nitrobenzoate) and oxadiazon(5-tert-butyl-3-(2, 4-dichloro-5-isopropoxyphenyl)-1, 3, 4-oxadiazol-2-one)]. I$_{50}$ value of the tolerant wheat cultivars to oxyfluorfen was about 10$^{-4}$ , whereas that of the susceptible barley cultivars was about 10$^{-6}$ M, showing significant difference between the two groups. When foliage were applied with acifluorfen, bifenox or oxadiazon, the oxyfluorfen-tolerant wheat showed less decreased in shoot fresh weight and chlorophyll content than the susceptible barley. Also, when soil-applied with these herbicides test plants showed similar tendency in foliar application. Electrolyte leakage from the tissue treated with these compounds was the more influenced in the barley than the wheat. Malondialdehyde(MDA) production as index of lipid peroxidation was greater in the barley than the wheat by treatment of these compounds. Therefore, the differential sensitivities of wheat and barley to protoporphyrinogen oxidaseinhibiting herbicides was showed by our greenhouse and in vitro experiment. The absorption rates of $^{14}$ C-oxyfluorfen were higher in the barley than the wheat. And this tendency was showed appararitly difference by increase of treatment durations. After the oxfluorfen and oxadiazon treatment, the tolerant wheat did not show the structural damage in leaf surface, but the susceptible barley was damaged in the leaf waxy layer. However, the acifluorfen and bifenox treatment showed no difference between wheat and barley. The anatomical changes by these compounds treatment were not observed in the tolerant wheat but epidermal cell and mesophyll cell were highly broken in the susceptible barley.

• 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.