• Korean Journal of Medicinal Crop Science
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• v.7 no.2
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• pp.89-93
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• 1999

This study was carried out to investigate the effects of planting density, time and frequency of pinching on growth and yield of Lycium chinese Miller cultivated in vinyl house. This experiment was conducted at the experimental field of Cheong-yang Agriculture High School, Cheong-yang, Chung-nam province, in 1997 to 1998. The number of flowers, fruit setting number and dry weight of fruits per branch were increased as the spacings were wider, but the fruit yield per unit area was decreased up to the narrowest spacing plot of $60\;{\times}\;20cm$. The good results of growth status and fruit yield was obtained at the early pinching in May 5. As the more frequent pinching were treated, the more number of flowers and fruits per branch were produced, showing increase of fresh and dry yield, because of much more branches per plot.

• Journal of Environmental Science International
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• v.5 no.5
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• pp.585-592
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• 1996

Trifluralin (2, 6-dinitro-N, N-dipropyl-4- (trifluormethyl) benzenamine) was applied preemergent to soybean in plots drained or nondrained, in louisiana. Plots 14.6 ha were arranged to give 1683 g/ha of trifluralin. The half life of trifluralin in the top 15 cm of soil was 42.6 darts and f6.0 days in nondrained plot and drained plot, respectively. The concentrations of trifluralin in surface runoff water and subsurface runoff water were 0.62 ng/ml-0.02 ng/ml and 11.06 ng/ml-0.02 ng/ml, respectively. The concentration of trifluralin in runoff water was smaller than 2 ng/ml for trifluralin of U.S. Environmental Protection Agency advisory. Total loss of trifluralin in runoff water was 0.021 % of applied amount at drained plots during three month after application. Trifluralin was moved hardly in the water. Subsurface drainage -reduced trifluralin losses because concentration of trifluralin in the subsurface runoff water in drained fields was low.

• Korean journal of applied entomology
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• v.23 no.4 s.61
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• pp.237-241
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• 1984

The trichogrammatidae ego parasite of the green rice leafhopper (GRLH), paracentrobia andoi, were investigated to know their parasitic activities after overwintering in the paddy banks and fallow fields, their seasonal variation and per cent parasitism in the paddy fields of Gyeongnam provincial O.R.D. at Jinju from 1982 to 1984. The parasitic activities of Paracentrobia andoi after overwintering in the Paddy banks in early Masch were high and tended to decrease remarkably since early April by moving to the fallow fields. The parasitic rate of paracentrobia andoi on GRLH was $21\%$ between late April and early May. the peak of egg laying period of GRLH. The per cent parasitism of the wasps in fallow fields was an average of $0\%$ in Gyeochang and Namji and $9.6-29.2\%$ in Namhae, Kimhae and Jinju. The parasitic activites of Paracentrobia andoi had three peakrs in paddy field, however, the highest peak was ovserved between mid- August and early October. The per cent egg parasitism of Paracentrobia andoi was an average of $16.5\%$ on second generation of Nepotettix cinctireps and $36.7\%$ on third generation of the leafhopper.

• Journal of Bio-Environment Control
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• v.17 no.2
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• pp.110-115
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• 2008

To evaluate growth chracteristics, vitamin C content and antioxidative activity of Sedum sarmentosum, 13 local strains were cultivated in the field. Keumsan, Bucheon, and Pocheon strains had narrow and oblong leaf, long hight, and slender stem compared to the other strains. Wanju and Gunsan strains were not formed flower stalks, and did not flower during the flowering time. Vitamin C contents were ranged from 407.8 to $434.4\;mg{\cdot}kg^{-1}$, and it was high in Gwangyang, Buan, Wanju, and Gunsan strains. But vita min C contents didn't show a significant difference among strains. In antioxidative activity between fresh and freeze dried shoots, electron donating abilities (EDA) were ranged from 45.0 to 66.5% in MeOH extract of fresh shoot, and from 61.3 to 66.5% in MeOH extract of freeze dried shoot. Gwangyang, Suncheon, Wando strains showed high EDA compared to the others. Vitamine C content and antioxidant activity were highest in Gwangyang strain.

• Korean Journal of Plant Resources
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• v.14 no.1
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• pp.38-42
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• 2001

This study was conducted to stable direct sowing cultivation with seedling growth promotion by plant growth regulator treatment in onion seed(Allium cepa L.) The emergence percentage of soaked seed in BA, GA$_3$, and kinetin solution were higher than control seed, and those were 93.0, 94.3, 93.8%, respectively. The plant height was significant elongation in growth regulators treated seed, and those effects were high GA$_3$, kinetin and BA in the order, and the extend were high as increasing the growth regulator solution concentration in GA$_3$ and BA, and that was reverse in kinetin. The No. of leaf was increased in growth regulators treated seed, and the extend were similar among the growth regulators. The No. of root was increased significantly in growth regulators treated seed, and the extend were high in GA$_3$, BA and kinetin in the order.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.4
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• pp.512-517
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• 1995

Effects of nitrogen top-dressing method on quality of barley were evaluted over amount of 2 and 4 kg per 10a on volcanic ash soil in Japan under regrowth stage, productive tiller stage and heading stage. 55% milling time was longer by the amount of top- dressing, but that was not influenced by the times of top-dressing. And glassiness, whiteness, hardness and 8 minute- millng rate were not influenced by times and amounts of top-dressing. Crude protein rate of grain was increased by amount of nitrogen top-dressing, but that did not correlated with time of nitrogen top-dressing. Crude protein rate of grain was positively correlated with 55% milling time. But that did not correlated with whiteness of 8 minute-milled grain. 8 minute-milling rate was negatively correlated with whiteness of 8 minute-milled grain. There was no visible difference of protein matrix with scanning electron microscope in different nitrogen levels.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.1 no.1
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• pp.26-31
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• 1963

1. This experiment was conducted with paddy rice in replicated field plot of clay load in Chung Puk College. This experiment has been intended to find out the suitable polt for increasing the yield of rice plant among the 36 plots which consist of 3 factors; deep plowing, heavy fertilizer and thick planting. 2 According to the standard and the heavy fertilizer applications, spikes and grains per phyung have been compared. It has been find out that the higher yield can be obtain in such plots as these; (1) the plot with standard fertilizer application, 15cm plowing depth and 400 hill per phyung, (2) the plot with two times as much fertilizer application, 30 cm plowing depth and 300 hills per phyung, (3) the plot with three times as much fertilizer application, 30cm plowing depth and 300 hills, or 45cm plowing depth and 400hills per phyung. 3. In the yield of brown rice, there has been significant difference in each main factor: hills per phyung, the plowing depth and the amount of fertilizer, and in the first order interaction; depthxfertilizer, depthxhills and hillsxfertilizer, and in the 2nd order interaction; depthx hillsxfertilizer. 4. In the plots with 30cm plowing depth, thick, planting of 200∼300 hills per phyung and two times as much fertilizer, the yield of rice has been superior to others.

• Research in Plant Disease
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• v.10 no.1
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• pp.13-16
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• 2004

A basal stem rot disease of potato (Solanum tubersum) grown on hydroponic system in greenhouse was found in Jeju-city, Jeju Province of Korea in January 2001. The symptoms occurred on basel stem and root, and than plants eventually were died. The casual fungus isolate from basal stem rot symptom and identified to be Pythium myriotylum on the basis of mycological characteristics; Main hyphae wide were 8.4 ${\mu}{\textrm}{m}$ in size. Oogonia were spherical, smooth, mostly terminal in shape and 26.4∼31.2 ${\mu}{\textrm}{m}$ in size. Antheridia were 9.6∼14,4${\times}$4.8-9.6 ${\mu}{\textrm}{m}$ in size. Oospores were spherical, smooth, aplerotic in shape and 21.6∼26.4 ${\mu}{\textrm}{m}$ in size. This is the first report on the basal stem rot of potato caused by P. myriotylum in Korea.

• Research in Plant Disease
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• v.12 no.3
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• pp.278-283
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• 2006

The effect of calcium cyanamide($CaCN_2$) on suppression of clubroot of Chinese cabbage was evaluated in the fields infested with Plasmodiophora brassicae at National Institute of Highland Agriculture, Pyeongchang, Korea, from 2002 to 2003. Calcium cyanamide was found to be more effective in reducing disease severity than flusulfamide dust powder. The optimal dosage of calcium cyanamide for control of clubroot of Chinese cabbage was 61 kg/10a. When calcium cyanamide was incorporated into soil at 5, 10, 15 and 20 days before planting(DBP), maximum disease suppression was obtained in the plot with calcium cyanamide, applied 5DBP. The fertilizer property of calcium cyanamide as a nitrogen fertilizer was also investigated by comparing with urea on cv. CR Gangta, a resistant variety of Chinese cabbage. The nitrogen uptake in calcium cyanamide treatment(17.6 kg/10a), was not significantly different from that of urea(17.8 kg/10a). These results indicated that calcium cyanamide could be used as a soil disinfectant as well as a nitrogen fertilizer.

• International Journal of Highway Engineering
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• v.1 no.1
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• pp.85-96
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• 1999

This study was performed to evaluate performance of polymer-modified asphalt mixtures and specially designed reinforcement techniques against reflection cracking of the asphalt pavement overlay. Selected polymers were used for asphalt modification and polyester fiber, a polypropylene film (vinyl) and a grid were used for mixture reinforcement. Using the asphalt mixture with optimum asphalt content, a slab was made and cut into two pieces of specimen. A layer of grid or vinyl was placed at the bottom of specimen to strengthen the pavement layer against crack. A repeated loading was applied to the asphalt mixture specimen which is Placed on a cement concrete with a pseudo-crack. Crack propagation under repeated loading was monitored and effectiveness of the devised crack retarding techniques was evaluated. From the test results. a significant retardation of mode I crack progress was monitored from some of the modified and reinforced asphalt mixtures.