• Weed & Turfgrass Science
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• v.2 no.2
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• pp.122-130
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• 2013

The object of this study is to review the current states of the characteristics and strategies to control annual bluegrass to apply information to the circumstance of South Korea. Annual bluegrass is one of the most widespread turfgrass species which has great ability to produce seedhead and shoot growth. It also has ability to tolerate low mowing height and to form uniformity of turfgrass when it is established. Annual bluegrass is well-known as weak turfgrass for high and low temperature. High rate of nitrogen and phosphorus improves growth of annual bluegrass. To control annual bluegrass, deep and infrequent irrigation is more effective than light and frequent irrigation. Clipping removal is more effective than clipping return to control annual bluegrass. Prodiamine, bensulide, and dithiopyr are applied as pre-emergence herbicide, and ethofumesate and bisbyribac-sodium are used as post-emergence herbicide. Paclobutrazol and flurprimidol are used as plant growth regulator. Trinexapac which is one of the most popular plant growth regulators (PGRs) in South Korea is not proper to control annual bluegrass because it accelerates improve growth of annual bluegrass in summer. Although chemical control is mainly used in South Korea, combination of cultural and chemical control may be the strategy to maximize effectiveness to control annual bluegrass.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.2
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• pp.89-98
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• 2008

The purpose of this study was to suggest the basic data for establishment of wildflower pastures. The experimental design includes two treatments: Native wildflower pasture (NWP, Kentucky bluegrass + native wildflower 8 species) and Introduced wildflower pasture (IWP, Kentucky bluegass + introduced wildflower 24 species). The field trials were carried out on the experimental pastures plots at Chungnam National University throughout from Sep. 2006 to Dec. 2007. The results obtained are as fellows: In terms of the flower color in the wildflower pastures, the IWP was found more various than the NWP. But such problems as seasonal distribution and continuity were raised and moreover the time of flowering depended mainly upon the spring season. Even though the flower color in the NWP did not show up its variousness, seasonal distribution and continuity were found comparatively satisfactory. To perennially maintain the botanical composition, the variousness of wildflower species are found important after examining locally the beginning rearing and flowering characteristics of wildflowers as well as the basic turfgrass. Moreover, when the wildflower pastures was constructed in autumn, since most of the introduced wildflower were annuals, it maintained various botanical composition before wintering, but after wintering the botanical composition were found simplified due to the winter tolerance. The NWP did not show any problems in the winter tolerance but it could not make the botanical composition diversified. Accordingly, to maintain the wildflower pasture for many years, diversifying wildflower species based upon perennials including annuals seems to be good.

• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.4
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• pp.209-214
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• 1991

The germination of seeds is developmentally complex process requiring water uptake, which is regulated by both genotypic and environmental factors. The present study was undertaken to determine the difference in germination characteristics, and to compare the ability of the logistic and Weibull functions to describe the cumulative germination curve when two levels of osmotic potential(0, -5 bar) were put to seeds of alfalfa, tall fescue, orchardgrass, and Kentucky bluegrass. The effects of grass type, osmotic potential, and their interaction on the total germination and coefficient of germination velocity were significant(P<0.01). The Weibull equation for predicting percent cumulative germination curve of alfalfa had significantly lower residuals than the logistic equation regardless of osmotic potential(P<0.01), indicating that the Weibull equation was more efficient than the logistic equation to fit the data of the percent cumulative germination of alfalfa. The rate parameter from the logistic equation was decreased under water stress, whereas the scale and shape parameters were increased. There were significant differences in days to 20% germination estimated from the logistic and Weibull equations.

• Spatial Information Research
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• v.3 no.1
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• pp.47-53
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• 1995

The weed survey in lowland rice fields through Korea was conducted in 1992 to determine a change of the weed communities based on different regions, soil types, planting methods, and cultural practices. GIS was applied to identify a spatial analysis of predominant weed species in specific region. On behalf of vegetatine analysis such as absolute and relative density, absolute and relative frequency, importance value, and summed dominance ratio(SDR), there was highly dominant with a perennial weed species, Eleocharis kuroguwai Ohwi over whole country. However, in particular it was most predominant at southem area of Gyunggi province in Korea. Thus, rice farmers of this area have to introduce a specific comperhensive control strategy against this predominant weed species.

• Journal of The Korean Society of Grassland and Forage Science
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• v.6 no.1
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• pp.38-43
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• 1986

This field experiment was conducted to determine the effects of shading degrees (0 : full sunlight, 25, 50 and 75%) on the early growth characteristics and winter survival of grasses. For the test different artificial shading houses were established and pasture species used were orchardgrass, timothy and perennial ryegrass. The experiment was performed at Livestock Experiment Station in Suweon, and sowing date was Aug. 25, 1984. The results are summarized as follows : 1. Generally, root length, new root length, number of new root and tillers of grasses were increased at 0% (full sunlight) of shading, followed by 25, 50 and 75% of shading degrees, in that order. Plant length and leaf elongation, however were increased at 50% of shading, followed by 75, 25 and 0%. 2. The percentage of winter killing of grasses was significantly (P<0.05) increased as the shading degrees increased. Also the percentages of winter killing were 10.1% in orchardgrass, 9.5% in timothy and 14.2% in perennial ryegrass, respectively. 3. A significant negative correlations were observed in the relationship between winter killing and tillers, new root length and number of new root of grasses. However, there were positive correlations between winter killing and plant length or leaf elongation under shading conditions. 4. As the shading degrees are increased by 0, 25, 50 and 75%, the NAR of grasses was tended to be decrease to 10.98, 11.52, 9.81 and 6.12 g/$m^2$/day, in that order. Also there was a negative correlation (r=-0.5943*) between winter killing and NAR of grasses, and NAR of orchardgrass, timothy and perennial ryegrass were 8.58, 8.53 and 11.71 g/$m^2$/day, respectively.

• Journal of Animal Science and Technology
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• v.47 no.5
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• pp.877-890
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• 2005

This study was carried out to determine the effect of different growing stages of winter cereal crops on the quality of silage materials and silages. Silages were made from the silage materials harvested at four growing stages(boot, heading, flowering, and yellow ripe) of barley, rye, oat, and wheat. Approximately 1 kg of silage materials harvested from each growing stage stored in vinyl bags with vacuum packing method and fermented at room temperature for 40 days. As the growing stages progressed, the moisture and crude protein contents of the silage materials decreased, and fiber contents(NDF, ADF and hemicellulose) increased. All the silage materials showed significantly higher contents of water soluble carbohydrate in the boot stages than in the flowering and yellow ripe stages. There was no tendency in acetic acid contents of silage materials cut at different growing stages. The overall pH of silage materials were in the range of 5.91-6.01, and there was no significant difference among growing stages. Buffering capacity of silage materials were in the range of 26.23-29.47meq/100g DM, and showed a tendency to decline as the growing stages proceeded. The moisture and crude protein contents of silages decreased significantly in all species as the growing stages proceeded, and the fiber contents vice versa. As the growing stages proceeded, the pH of the silages tended to increase, and the acetic, butyric, and lactic acid contents tended to decrease. The buffering capacity of silages had a tendency to decrease as the growing stages of winter cereal crops proceeded. Therefore, these features described above should be taken into consideration in order to make silages from winter crops economically.

• Korean Journal of Environmental Agriculture
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• v.8 no.2
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• pp.119-127
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• 1989

The minimum concentrations of nonionic and anionic surfactants inducing phytotoxicity were investigated after spraying or flooding surfactant solutions to annual plants. Of the sufactants tested, LE, NP, SPSS, LN, PAAS and DBC induced phytotoxicity at the lowest concentrations through all treatments and Tween, Span, SP, SC, STPP and CLIS induced the least phytotoxicity even at high concentration. At flooded paddy field tests, anionic surfactants induced phytotoxicity at the lower concentration than nonionic, but showed similar tendencies with other treatments. In pre-emergence treatments of upland and dry paddy field tests, there was little phytotoxicity induced at over 10 percent, while phytotoxicity was induced at the lowest concentration among 6 treatments in flooded paddy field tests.

• The Journal of the Korean bone and joint tumor society
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• v.5 no.1
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• pp.35-43
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• 1999

The authors reviewed and analyzed the pathologically confirmed 230 cases of benign soft tissue tumors which had been treated at Department of Orthopaedic Surgery in Seoul Hospital, Hanyang University College of Medicine from February 1984 to November 1997. The following results were obtained. 1. The most common benign soft tissue tumors was ganglion(26.5%) followed by hemangioma(19.6%), lipoma(17.0%), Baker's cyst(13.0%) and neurilemmoma(7.0%) in decreasing order of incidence. 2. Benign soft tissue tumors were found evenly distributed over all age group. Hemangioma and lymphangioma were usually found to occur before 20 years old. 3. Female was affected about 1.3 times more common. But, Baker's cyst and neurilemmoma occurred most frequently in male. 4. In children, the most common benign soft tissue tumors was hemangioma followed by ganglion, lymphangioma, and lipoma. In adult, ganglion, lipoma, Baker's cyst, hemangioma were common. 5. The lower extremity was the predominant site of occurrence(60.0%). 6. Benign soft tissue tumors were taken by excision. Local recurrences were developed in 22(9.6%) out of 230 cases, especially in hemangioma.

• The Korean Journal of Pesticide Science
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• v.12 no.2
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• pp.103-110
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• 2008

To develop the third generation herbicidal cyclic imide (Cyl) derivatives, the new 1-(4-chloro-2-fluoro-5-propargyloxyphenyl)-3-thiourea derivatives were synthesized and measured their herbicidal activities ($pI_{50}$) in vivo (preemergence) against rice plant (Orysa Sativa) and barnyard grass (Echinochlor crus-galli). The synthetic yields (%) of aryl derivatives (21-40) in general was higher than that of alkyl derivatives (1-20). In case of alkyl derivatives, the synthetic yield depended on the structural forms of alkyl amine groups. From the results of correlation analysis between herbicidal activities and substituents, the compound 8 and 24 showed the highest herbicidal activity against the shoot and root of barnyard grass. Especially, the compounds 11 and 6 showed the selective herbicidal activities between rice plant and barnyard grass.

• Korean Journal of Weed Science
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• v.7 no.2
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• pp.220-235
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• 1987

The experiment was carried out to find the feasibility of using Oxyfluorfen in the paddy fields by investigating the difference of selective activity of Oxyfluorfen among rice cultivars and major paddy weed species. The dosage of Oxyfluorfen that show selective activity between rice cultivars and weed species ranged from 0.1 to 0.4kg ai/ha. The degree of growth inhibition was in order of whole-plant soaking application > root soaking application > stem bandage application, and in that case $10^{-5}$M Oxyfluorfen was treated after emergence. Especially the growth inhibition of rice cultivars and Cyperus serotinus was low, among others. Photosynthesis was severely inhibited at the Oxyfluorfen level above $10^{-4}$ M in all the tested weeds, but inhibition of respiration was not to be seen. Isolated single cells of two rice cultivars and Cyperus serotinus were tolerant to $10^{-5}$M Oxyfluorfen,but those of Echinochloa crus-galli and Sagittaria pygmaea were susceptible comparatively. The growth inhibition of suspension cultured rice cell induced by the increments of Oxyfluorfen concentration, and the degree of inhibition was higher in C.V. Mushakdanti than in C.V. Aichiasahi.