• 아시안잔디학회지
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• 제24권1호
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• pp.24-30
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• 2010

우리나라 골프장에 조성된 한지형 잔디 5종류 48품종(creeping bentgrass 9품종, kentucky bluegrass 20품종, tall fescue 10품종, perennial ryegrass 5품종, chewing fescue 4개 품종)에 대하여 봄철에 발병하는 병의 종류와 병의 심각성을 평가하였다. Rhizoctonia cerealis에 의해 늦가을부터 자연적으로 발병한 yellow patch 뿐 이었다. 잔디 종류 중에서 Perennial ryegrass 품종과 creeping bentgrass 품종에서 이른 봄에 심각하게 발생한 반면, 다른 종류의 품종들은 통계적으로 유의성이 없었다. Creeping bentgrass 품종 중에는 "Pennlinks II"가 가장 감수성을 보였다. Yellow patch의 증상은 가장자리가 자줏빛갈색을 보였으며, 직경의 크기는 5 cm-50 cm 이었다. 이결과로 볼 때 yellow patch의 발병 률은 잔디 종류와 품종 간에 큰 차이를 보였다.

• 아시안잔디학회지
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• 제6권2호
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• pp.99-111
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• 1992

국내 골프장에 식재된 bentgrass (Agrostis palustris Huds), zoysiagrass (Zoysia japonica Steud) 및 Kentucky bluegrass (Poa pratensis L.)에 잎마름증상(yellow patch)을 나타내는 병반 부위에서 병원균을 분리ㆍ동정한 결과 2핵성인 Rhizoctonia cerealis로 동정되었다. 병원균은 잔디의 관부와 엽조직을 침해하였으며, 병징은 bentgrass의 경우 1m 내외의 둥근 고리모양의 병반을 형성하고, 병반 가장자리의 잔디잎은 초기에는 붉은색을 띠며 병이 진전됨에 따라 갈변하였다. Zoysiagrass에는 직경 30~40cm의 근사원형의 병반이 봄철 맹아시기에 발생하고, 병반 부위에서는 잔디가 맹아되지 않았다. 맹아된 잔디에는 부정형의 볏짚색 반점이 생기면서 고사되었다. Rhizoctonia cerealis의 균사직경은 2.5~6.3$mu extrm{m}$(평균 3.8$\mu\textrm{m}$)이었으며, 균사는 담황색을 띠고, 균총의 색은 밝은 갈색을 나타냈다. Monilioid cell 크기는 5.8~12.5$\times$l3.8~37.5$\mu\textrm{m}$였으며, 배지상에서 형성된 균핵의 크기는 0.2~2.0mm, 균핵의 색은 처음에는 흰색을 띠다가 성숙해가면서 갈색을 나타냈다. 온도에 따른 균사의 생장은 23$^{\circ}C$에서 가장 양호했다. 병원성 검정 결과 분리균간에 병원성에는 다소 차이가 있었다.

• 농업과학연구
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• 제38권2호
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• pp.243-248
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• 2011

This investigation was conducted to develop an integrated disease management system against large patch disease occurred in a golf course. Large patch, brown patch, and Rhizoctonia blight sometimes are used interchangeably by turfgrass managers and researchers, Large patch disease of zoysiagrass is caused by a soilborne fungus called Rhizoctonia solani. Although this fungus is very similar to the one that causes brown patch disease of cool-season turfgrasses in mid-summer. Large patch development is favored by high thatch and soil moisture. Avoid overwatering the turfgrass, especially in the fall or early spring. Poorly-drained areas are very susceptible to injury from large patch and should be reconstructed (draining tiles, etc) to avoid soil saturation. However, control of yellow patch with fungicides is normally not recommended because the disease has only cosmetic effects and symptoms are usually very short-lived. Therefore, we reviewed the symptom of large patch to look for control method by soil management method.

• 아시안잔디학회지
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• 제24권1호
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• pp.9-15
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• 2010

2008~2009 겨울 동안 강원도와 전라북도 소재 골프장에서 분리한 황색마름병원균(Rhizoctonia cerealis Van der Hoeven)과 설부갈색소립균핵병원균(이하 설부병원균)(Typhlua incarnata Lasch ex Fr.)에 대한 화본과 식물과 잔디 종(품종)의 저항성이 실내에서 평가되었다. 분리균주의 병원성 검정결과 대부분의 잔디와 화본과 식물에 병을 일으켰지만 균주간의 병원력 차이도 발견되었다. 황색마름 병균은 잔디의 지제부위를 통해 감염하여 연한 갈색의 원형 반점 증상을 보이다가 진전되면 적색을 띄다가 결국 진한 갈색의 증상으로 나타났다. 설부병 증상은 수침형 반점으로 시작해서 전체 식물체를 갈색으로 고사시켰는데, 대부분 감염부위에서 흰색의 균사체가 식물체와 토양을 뒤덮었고 진전되면 다양한 크기의 갈색과 검은색의 독특한 균핵을 형성하였다. 병 발생은 습실기간이 길어질수록 증가하는 경향이었다. 화본과 작물과 잔디의 종(품종)간에는 병원균의 병원력에 차이도 나타났으며 두 병원균에 대해 양적인 차이를 보였다.

• Journal of the korean society of oceanography
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• 제39권1호
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• pp.96-106
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• 2004

A total of 116 surface sediment samples were obtained on the Yellow Sea and analyzed for grain size and geochemical elements in order to interpret the present sediment transportation. Thirty-nine cores and 3,070 line-km shallow seismic profiles are analyzed for sedimentary records of Yellow Sea in the past. Results show that the boundary of sediment transport between Korean side and Chinese side is about between $123^{\circ}E$ and $124^{\circ}E$. The similar result is produced from Shi et al. (in this publication). Two cyclonic patterns of surface sediments are recognized in the northeastern and southwestern Yellow Sea, while the strong front zone of the mud patch and sandy sediments are found in the southeastern Yellow Sea (the southwestern part of Korean coasts). The formation of fine-particle sediment packages, called for Northwest Mudbelt Deposit (NWMD), Hucksan Mudbelt Deposit (HSMD) and Jeju Mudbelt Deposit (JJMD), are resulted from eddies (gyres) of water circulations in the Yellow Sea. NWMD has been formed by cyclonic (anticlockwise) eddy. NWMD is composed of thick, homogeneous, relatively semi-consolidated gray clay-dominated deposit. On the other hand, HSMD and JJMD are formed by anticyclonic (clockwise) eddies. They are thick, homogeneous, organic-rich gray, silt-dominated deposit. Both core and surface sediments show that the middle zone across Chinese and Korean side contains bimodal frequency of grain-size distribution, indicating that two different transport mechanisms exist. These mud packages are surrounded by sand deposits from both Korea and China seas, indicating that Yellow Sea, which is the shallow sea and epicontinental shelf, is formed mostly by sand deposits including relict sands. The seismic profiles show such as small erosional/non-depositional channels, sand-ridges and sand-waves, Pleistocene-channelfilled deposits, a series of channels in the N-S major channel system, and thick Holocene sediment package, indicating that more complex sedimentary history exists in the Yellow Sea.

• 아시안잔디학회지
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• 제13권4호
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• pp.201-212
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• 1999

In use of pesticides in golf courses has been increased steadily. Environmental concern as well as decrease in efficiency led the turfgrass management into an alternate approach of using beneficial microorganism to deal with turfgrass pests. This study was focused on the use of such microorganisms for improving cultural environment and minimizing the use of pesticides. Microorganisms antagonistic to turfgrass diseases were applied to zoysiagrass fairways and creeping bentgrass greens in Yusung country club. Tharch accumulation, disease occurrence, and other cultural environments were compared among the combinations of microorganisms and suppliemental N applications. The application of microorganisms antagonistic to turfgrass diseases improved turf resiliency. Thatch thickness was 3.03cm in the control plot but it was 2.11cm in plots treated by microorganisms, indicating significant effects of microorganism application on reduction of thatch accumulation. Number of microorganism that can decompose of cellulose was higher at the plots treated with useful microbial products and it was considered that existence of higher population of microorganisms resulted in reduction of thatch accumulation. In the evaluation of relationship between thatch accumulation and disease occurrence, greater thatch accumulation was observed at the golf courses which have been frequently infested by large patch. However, the rate of thatch accumulation varied among surveyed golf courses regardless of the year of turf establishment. Therefore, management practice which can be effective for reduction of thatch could result in large patch suppression. The application of microorganisms on the established turfgrasses reduced the occurrence rate of pythium blight and yellow path diseases, whereas occurrence of brown patch and dollar spot increased.

• Mycobiology
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• 제44권4호
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• pp.330-334
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• 2016

In 2010, disease symptoms, including necrotic lesions on stems and leaves with circular yellow-brown or irregular brown color patches, were observed on cool-season turfgrass at golf courses (OHCC) and the Daegu University research farm in Gyeongbuk, Korea. We isolated the causal agent and identified it as Waitea circinata var. zeae by morphological characterization and molecular analysis. To the best of our knowledge, this is the first report of brown patch caused by W. circinata var. zeae on cool-season turfgrass in Korea.

• 아시안잔디학회지
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• 제12권1호
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• pp.23-30
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• 1998

174 isolates of soil microorganisms were isolated from E-golf club from Apr.1997 through Oct. 1997. And 27 strains of them were selected through the inhihition test of mycelial growth. In the same period, soil-borne diesease pathogens, "Rhizoctonia", causing Large patch, Brown patch, Spring dead spot, and Yellow patch were isolated from the diseased areas in E-golf and S-golf club. The antagonistic activity of the strains against the pathogens was tested to select the excel-lent antagonists. In contact with the fungicides, the survivability of the antagonists was tested to assess the compatibility of the antagonists with the pesticides. The results were as follows: 1.Suppression of Rhizoctonia by Antagonists. Antagonistic activity of 27 strains against the pathogens was: tested in vitro. In the result, 3 isolates(B-7, B-15, B-41) of bacteria and 2 isolates(F-5, F-47) of fungi were superior to the rest. 2.Compatibility of the antagonists: with the fungicides: With 13 kinds of pesticides widely using Golf Club, Compatibility of 5 antagonists: were finally tested to select the strains: that mostly survived in contact with pesticides. In the results:, two of five strains: were selected : one strain was bacteria B-15, the other strain was fungi F-47. 24h after the mixing with pesticides:, these two strains were shown to survive at 90% level and these were identified as Bacillus and Trichoderma, respectively. And the most compatible pesticides: with the antagonists were shown to Polytoxin-D thirarn(s:urvivability 99.4%) and Validamycin-A (survivability 98.6%). Keywords:Antagonist, Large Patch, Trichoderma, Compatibility, Fungicide.Fungicide.

• 아시안잔디학회지
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• 제9권3호
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• pp.235-252
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• 1995

Turfgrass Rhizoctonia blight is a severe disease in golf courses in Korea. Attempts were made in 1989 to 1994 to identify the Rhizoctonia species associated with turfgrass blights and also to examine their epidemiology. A total of 120 Rhizoctonia isolates collected were identified as R. solani AG1, R. solani AG2-2, R. cerealis(AG-D) and R. oryzas from brown patch, large patch, yellow patch and white patch, re-spectively. R. solani AG1 was mostly associated with brown patch of cool-season grasses. and most frequently isolated in June through July and also in September. R. solani AG2-2 was isolated exclusively from zoysiagrasses from April to November, most frequently in June through July and October through November. R. cerealis was isolated frequently from both creeping hentgrass in March through April and in November, and zoysiagrass in April and July. Thermophilic R. oryzae was isolated only from creeping bentgrass in August, although with very low frequency. R. solani AG2-2 was strongly pathogenic specifically to Korean lawngrasses(Zoysia japonica, Z.matrella, Z. tenuifolia), but non-pathogenic to creeping bentgrass(Agrostis palustris), bermudagrass (Cynodon dactylon), Kentucky bluegrass(Poa pratensis), perennial ryegrass(Lolium prenne), and creeping red fescue(Festuca rubra subsp. ruhra L.). R. cerealis was strongly pathogenic to zoysiagrass and bentgrass only, but was isolate-specific i.e., from non-pathogenic to pathogenic, for other turfgrasses. The mycelial growth was optimum at relatively high temperature ranges of 25~30$^{\circ}C$ for R.solani AG1, AG2-2 and R. oryzae, while the mycelial growth of R. cerealis was initiated at $^{\circ}C$ and almost ceased at or above $^{\circ}C$.

• ALGAE
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• 제34권4호
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• pp.315-326
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• 2019

Northeastward drifts of massive Sargassum patches were observed in the East China Sea (ECS) and Yellow Sea (YS) by the Geostationary Ocean Color Imager (GOCI) in May 2017. Coverage of the brown macroalgae patches was the largest ever recorded in the ECS and YS. Three-dimensional circulation modeling and Lagrangian particle tracking simulations were conducted to reproduce drifting trajectories of the macroalgae patches. The trajectories of the macroalgae patches were controlled by winds as well as surface currents. A windage (leeway) factor of 1% was chosen based on sensitivity simulations. Southerly winds in May 2017 contributed to farther northward intrusion of the brown macroalgae into the YS. Although satellite observation and numerical modeling have their own limitations and associated uncertainties, the two methods can be combined to find the best estimate of Sargassum patch trajectories. When satellites were unable to capture all patches because of clouds and sea fog in the ECS and YS, the Lagrangian particle tracking model helped to track and restore the missing patches in satellite images. This study suggests that satellite monitoring and numerical modeling are complementary to ensure accurate tracking of macroalgae patches in the ECS and YS.