• Weed & Turfgrass Science
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• v.2 no.4
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• pp.381-386
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• 2013

Recent climatic changes by global warming include increased amount and intensity of rainfall. This study was conducted to find out possible roles of turfgrasses to reduce the impact of climatic changes, especially surface soil erosion. Soil erosions by intensive rain were measured after each significant precipitation from the artificially sloped plots of zoysiagrass, cool-season grass mixture of Kentucky bluegrass and perennial ryegrass and other typical korean summer crops. Sodded zoysiagrass resulted in minimal annual soil erosion followed by strip-sodded zoysiagrass and cool-season turfgrass mixture while dry-field rice and bean cultivations eroded the surface soils of 5 to 10 MT $ha^{-1}yr^{-1}$ and pepper cultivation resulted in 7 to 14 MT $ha^{-1}yr^{-1}$ annual loss of surface soil. Annual loss of surface soil from bare land with hand weeding was up to 18 MT $ha^{-1}yr^{-1}$ while greatly reduced soil erosion was observed from weed grown treatment.

• Asian Journal of Turfgrass Science
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• v.24 no.2
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• pp.161-164
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• 2010

Dollar spot, caused by Sclerotinia homoeocarpa F.T. Bennett, is the most economically important turfgrass disease on golf courses in North America due to its persistent nature. Fungicides, plant growth regulators, and other products were evaluated for preventative control of dollar spot and the secondary effects on brown patch and Pythium in a mixed stand of creeping bentgrass and annual bluegrass golf course putting green. Most fungicides provided excellent control of dollar spot throughout the trial but Rhapsody alone did not provide adequate control. Civitas applied alone and tank-mixed with Banner MAXX(R) and Daconil Ultrex(R) provided acceptable control throughout the study. No phytotoxicity was observed on any of the treatments applied but a darker green color and reduction in turfgrass growth was observed in a treatment with plant growth regulator, Trimmit. Treatments that contained Civitas and the Civitas Harmonizer also exhibited green pigmentation.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.1
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• pp.73-82
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• 2009

The experiment was carried out from January through December in 2008 at Chungnam National University and the Unbong Animal Genetic Resources Station, NIAS. The experimental animals were twelve dairy goats (female, $30{\pm}1.8kg$), twelve Korean native Boats(female, $24{\pm}2.4kg$) and five sika deer(female, $92{\pm}5.2kg$). A total of 11 different types of hay and straw were tested in this study: such straw imported from USA in 2006 as annual ryegrass, perennial ryegrass, tall fescue and Kentucky bluegrass, and such hay imported from USA in 2007 as alfatfa, bermudagrass, timothy, kleingrass, oat and orchardgrass, and such domestic hay as mixed hay There were significant differences in chemical composition and in vitro dry matter digestibility (IVDMD) among the various types of imported hay and straw (p<0.05). Besides alfalfa hay and orchardpass hay all of the imported hay contained lower crude protein (CP) and IVDMD but contained higher neutral detergent fiber(NDF) and acid detergent fiber (ADF) than the domestic hay. According to the kinds of the imported hay, relative feed value (RFV) made the difference and the hay grades were ranged from 4 to 5, based on the RFV. According to the kinds of the imported hay, there were markedly differences in dry matte. (DM) intake and palatability ranking among dairy goats, Korean native goats, and sika deer. DM intake and palatability ranking were high in common between orchardgrass hay and bermudagrass hay, but Kentucky bluegrass straw, tall fescue straw, perennial ryegrass straw and annual ryegrass straw were proved to be very low in DM intake and palatability ranking. In conclusion, the quality and palatability among the imported hay that was tested in the study were quite variable and lower than expected. It is required to establish a better feed evaluation system for the imported hay.

• Asian Journal of Turfgrass Science
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• v.12 no.4
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• pp.203-210
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• 1998

Environmental concerns arising from synthetic herbicides in plant management systems have led to an interest in plant-derived compounds as natural herbicides. Inhibitory effects of compounds extracted with 50% methanol from corn (Zea mays L.) and pine (Pinus densiflora L.) were evaluated on large crabgrass (Digitaria sanguinalis (L.) Scop.), annual bluegrass Poa annua L.), radish (Raphanus sativus L.), and perennial ryegrass (Lolium perenne L.) The aqueous extracts inhibited seed germination and had postemergence activity on the four species. The stability of biological activity of corn grain, stover, and root extracts was not affected by heating to $135^{\circ}C$ or freezing/thawing treatments when applied at levels above 0.25kg m(sup)-2 based on dry weights of powders before extraction. Heating reduced the activity of pine litter and bark extracts at all levels except the highest application level but had little effect on pine needle extracts.

• The Plant Pathology Journal
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• v.29 no.1
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• pp.93-98
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• 2013

Bacterial wilt is a vascular wilt disease caused by Xanthomonas translucens pv. poae that infects Poa annua, a grass that is commonly found on golf course greens throughout the world. Bacterial wilt causes symptoms of etiolation, wilting, and foliar necrosis. The damage is most prevalent during the summer and the pathogen can kill turf under conditions optimal for disease development. Fifteen isolates of X. translucens pv. poae were collected from northern regions in the United States and tested for virulence against P. annua. All 15 isolates were pathogenic on P. annua, but demonstrated variable levels of virulence when inoculated onto P. annua under greenhouse conditions. The isolates were divided into two virulence groups. The first group containing four isolates generally resulted in less than 40% mortality following inoculation. The second group, containing the other eleven isolates, produced between 90 and 100% mortality following inoculation. These results suggest that differences in the virulence of bacterial populations present on a golf course may result in more or less severe amounts of observed disease.

• Asian Journal of Turfgrass Science
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• v.26 no.1
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• pp.60-66
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• 2012

Crabgrass (Digitaria sanguinalis L.), Dandelion (Taraxacum platycarpum H. DAHLST.), Annual bluegrass (Poa annua L.), Gree kyllinga (Kyllinga brevifolia var.), Red clover (Trifolium pratense L.), Annual lespedeza (Kummerowia striata (Thunb.)Schindl.), Mugwort (Artemisia capillaris Thunb.), Horseweed (Erigeron canadensis L.), Field horsetail (Equisetum arvense L.) are major weeds in turf. In this study, 23 medicinal plant extracts were tested for herbicidal activities against crabgrass and dandelion in the course of major weed in turf. In pot experiment, we implemented pre-emergence application used medicinal plant extracts showed herbicidal activity in petridish experiment. In effect, inhibition rates of germination were 61.0% at Curcuma longa extract and 62.5% at Cnidium officinale extract in crabgrass pot experiment, and 77.8% at Ailanthus altissima extract in dandelion pot experiment.

• Asian Journal of Turfgrass Science
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• v.13 no.2
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• pp.79-90
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• 1999

This study was conducted to provide basic understandings for proper management of zoysiagrass fairways. Mowing intervals of 2, 4 and 6-days, with and without aeration were compared at two fertility levels. Turfgrass quality, growth and pest infestation were evaluated. Turf density, number of tillers, leaf width and resiliency were significantly affected by mowing frequency. Turfgrass plots mowed every 2-day had greater density, tillering, and resiliency but had narrower leaf width compared to other mowing treatments. Clipping dry weight with every 2-day mowing increased in the early stage of mowing treatment regardless of fertilizer application rates but gradually decreased in the later stage of mowing treatment compared to every 4 or 6-day mowings. The dry weight of above-ground part was not affected by mowing frequency, but that of underground part was significantly higher for every 6-day mowing frequency(3.3kg/day/m2) compared to every 2 or 4-day mowings. The organic mater content in soil was not different among mowing treatments but it was significantly reduced by the core aerification treatment, indicating significant effect of core aerification on thatch decomposition. Occurrences of weeds such as annual bluegrass and crabgrass according to mowing frequency were greater in every 2-day mowing treatment, while plots mowed every 6 days had less weed occurrence. Occurrence of rusts significantly increased in high fertility plots and frequently mowed turfgrasses.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.325-325
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• 2017

In the 20th century, the average temperature of Korea has risen by $1.5^{\circ}C$, whereas it has risen by $0.6^{\circ}C$ globally. Few studies have investigated the effect of seeding date in hilly pastures on their growth characteristics and productivity. The purpose of this study was to elucidate the effect of seeding dates at a hilly pasture establishment on its growth characteristics and productivity caused by increasing temperatures in Korea. The experiments were conducted from 2014 to 2016 at Pyeongchang, South Korea, at an altitude 600-700 m above sea level. The composition of grass mixture was tall fescue, orchard grass, perennial ryegrass, Kentucky bluegrass, timothy, and white clover. Treatments comprised four seeding dates (August 13 and 27, and September 10 and 24). The establishment rate was lowest on September 24, resulting in only 20% establishment over the winter, and the proportion of weeds was highest on September 24 (58%). Early seedling growth before overwintering is a critical approach to ensure successful establishment of grassland. The main components were orchard grass and tall fescue on the early seeding date (August 13), and Kentucky bluegrass on the late seeding date (September 24). Late seeding increased the proportion of bare lands invaded by weed species, especially during second and third cutting periods. Early seeding date resulted in a progressive increase in biomass. Total annual production was significantly affected by the seeding date; lowest dry matter production was on September 24 ($2,441kg\;ha^{-1}$), whereas maximum dry matter yield was on August 27 ($6,608kg\;ha^{-1}$). The results of the study indicate that growth condition and productivity could be increased by early seeding, and seeding of grass in the Pyeongchang area should be completed before August 27. However, further studies are needed to determine the ideal seeding date at the hilly pasture establishment in Pyeongchang.

• Asian Journal of Turfgrass Science
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• v.25 no.2
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• pp.237-242
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• 2011

The 2011 Japanese Society of Turfgrass Science was divided in oral presentation, sectional meeting and small symposium, and the total 55 subject was announced. The oral presentation was reported physiological ecology of turf, disease and weed; field management; pesticidal activity and spectrum of new turf pesticides. Above all, there was presentation that investigated control method of necrotic ring spot of new turf disease and Cyperus brevifolius, annual bluegrass and mouse-ear chickweed. In addition, the control effect of new registration fungicide (Furametpyr) and herbicides (S-metolachlor, Flucetosulfuron and Foramsulfuron) were announced. There was various information interchange through 4 kinds of subjects of a golf course, ground turf, a urban park greens and ground cover plants greening by the sectional meeting, and the genetic resource of turfgrass discussed by small symposium. Specially, park greens sectional meeting was announced about the radioactive material contaminated on mechanism and effectively removal method of the radioactivity contaminant from public park, school ground and domestic lawn.

• Annual Conference on Human and Language Technology
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• 1994.11a
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• pp.409-415
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• 1994

Hitel 과 같은 전자정보 시스템은 사용자가 원하는 정보를 체계적으로 얻을 수 있도록 하기 위하여 메뉴들을 적당히 계층적으로 구성하여 제공하고 있다. 그러나, 보통 이 메뉴들의 계층이 정확한 분류법에 기초하여 만들어지지 않았을 뿐 아니라 그 양도 엄청나게 방대하여, 이 메뉴 계층을 이용하여 사용자가 원하는 정보를 얻기가 쉽지 않다. 실험적으로 보통 Hitel을 자주 이용하는 사람들도 자신이 주로 이용하는 메뉴들의 구성만 이해하고 있을뿐, 사용하지 않는 부분의 메뉴들의 구성은 잘 알지 못하는 것이 일반적이었다. 따라서 Hitel을 자주 이용하는 사용자도 자신이 이용해 보지 않은 정보를 얻기 쉽지 않으며, 더더욱 초보자에게는 이 메뉴계층을 이용하여 원하는 정보를 얻기가 쉽지 않은 실정이다. 본 연구에서는 정보검색 기술을 이용하여 Hitel과 같은 전자정보 시스템에서 사용자가 쉽게 자신이 원하는 정보를 얻을 수 있는 보조 시스템을 개발하고자 한다. 본 시스템은 사용자가 메뉴계층을 이용하기 전에 간략한 자연어로 입력을 주면, 여기에 적합한 메뉴나 실제 정보를 검색해 낸다. 따라서 사용자는 이 메뉴정보를 이용하여 메뉴계층을 쉽게 따라갈 수 있을 뿐 아니라, 경우에 따라서는 원하는 실제 정보를 검색하기 때문에 메뉴계층을 탐색할 필요가 없다. 본 연구에서는 자연어 입력을 최장 일치 방법으로 의미있는 명사들을 추출하여 불리한 질의어로 만든 후, 명사들 사이의 관계가 표현된 시소러스를 이용하여 이 질의어를 확장시킨다. 다음에 이 질의어들을 메뉴들과 부분/정확부합을 통하여 관련된 메뉴들을 찾아낸 후, 이들의 계층과제를 고려하여 최종 메뉴들을 검색한다. 본 시스템은 현재 C언어로 만들어져 구동중이며, 정확한 실험은 아직 하지 않았지만 높은 검색율을 보이고 있다. industrialized, was improved by introducing pressure in cooling procedure for both carbon and iron thermistors.er>$CHCl_3$>Hexane층 순으로 높은 활성을 나타냈다. 5. 아질산염소거능은 끝순, 들깨잎, 콩나물이 우수하였고 그중 들깨잎이 저해율 72%로 가장 높았으며, 용매분획 중에는 BuOH과 water추출물의 활성이 가장 높았다. 6. ACE 저해 효과는 고구마 부위별로는 끝순이 괴근에 비하여 1.5배 높았고, 들깨잎, 콩나물, 시금치보다 $1.9{\sim}3.7$배 높았다. 용매분획별로는 EtOAc, BuOH, water 추출물이 높은 활성을 보였다. 7. 이상을 종합하여 볼 때 고구마 끝순에는 페놀화합물이 다량 함유되어 있어 높은 항산화 활성을 가지며, 아질산염소거능 및 ACE저해활성과 같은 생리적 효과도 높아 기능성 채소로 이용하기에 충분한 가치가 있다고 판단된다.등의 관련 질환의 예방, 치료용 의약품 개발과 기능성 식품에 효과적으로 이용될 수 있음을 시사한다.tall fescue 23%, Kentucky bluegrass 6%, perennial ryegrass 8%) 및 white clover 23%를 유지하였다. 이상의 결과를 종합할 때, 초종과 파종비율에 따른 혼파초지의 건물수량과 사료가치의 차이를 확인할 수 있었으며, 레드 클로버 + 혼파 초지가 건물수량과 사료가치를 높이는데 효과적이었다.\ell}$ 이었으며 , yeast extract 첨가(添加)하여 배양시(培養時)는 yeast extract 농도(濃度)가 증가(增加)함에 따라 단백질(蛋白質) 함량(含量)도 증가(增加)하였다. 7. CHS-