• Title/Summary/Keyword: Summer patch

Search Result 21, Processing Time 0.029 seconds

Research Review on Turfgrass Disease in Korea (한국의 잔디병해 연구사)

  • Shim, Gyu Yul;Lee, Jung Han
    • Weed & Turfgrass Science
    • /
    • v.7 no.2
    • /
    • pp.87-97
    • /
    • 2018
  • Turfgrass provides various beneficial effects to our societies such as recreation, aesthetic components, and other public service. Diseases in turfgrass is the major issue, which cause quality problems in golf courses, playgrounds, parks and cultivation areas, and tremendous cost is required to prevent the diseases. Research activity and investigation for turfgrass disease remain to be further attributed when compared to other crops in Korea. In this study, we present previously reported turfgrass diseases researches, especially caused by fungal pathogens, and review the history of turfgrass research activity in Korea to contribute future turfgrass research direction. Research papers were searched and analyzed using Korea Educational and Research Information Service (www.riss.kr). More than eighty papers presented turfgrass diseases and among the papers, 50% were published in Korean Journal of Turfgrass. Half of the papers reported turfgrass diseases control. Research articles about large patch disease were the majority (36%), followed dollar spot (18%), Pythium blight (10%) and Typhular blight (8%). Number of the first disease reports in Korea were total fifteen. Total 542 fungicides have been registered in Korea to prevent turfgrass diseases and most of the fungicides were for brown patch, rust, yellow patch, dollar spot, snow mold, summer patch, anthracnose, Pythium blight, powdery mildew and algae. And we will also need to conduct ecological studies on turf diseases and to develop control methods with improved efficacy and environmentally-friend sound. Researches on epidemiology of turfgrass diseases which deals with the incidence, distribution, and interactions with other factors will be also greatly favored for precise control prescription, timing of control and use of less pesticides.

Composition and Distribution of Phytoplankton with Size Fraction Results at Southwestern East/Japan Sea

  • Park, Mi-Ok
    • Ocean Science Journal
    • /
    • v.41 no.4
    • /
    • pp.301-313
    • /
    • 2006
  • Abundance and distribution of phytoplankton in seawater at southwestern East/Japan Sea near Gampo were investigated by HPLC analysis of photosynthetic pigments during summer of 1999. Detected photosynthetic pigments were chlorophyll a, b, $c_{1+2}$ (Chl a, Chl b, Chl $c_{1+2}$), fucoxanthin (Fuco), prasinoxanthin (Pras), zeaxanthin (Zea), 19'-butanoyloxyfucoxanthin (But-fuco) and beta-carotene (B-Car). Major carotenoid was fucoxanthin (bacillariophyte) and minor carotenoids were Pras (prasinophyte), Zea (cyanophyte) and But-fuco (chrysophyte). Chl a concentrations were in the range of $0.16-8.3\;{\mu}g/land$ subsurface chlorophyll maxima were observed at 0-10m at inshore and 30-50 m at offshore. Thermocline and nutricline tilted to the offshore direction showed a mild upwelling condition. Results from size-fraction showed that contribution from nano+picoplankton at Chl a maximum layer was increased from 18% at inshore to 69% at offshore on average. The maximum contribution from nano+picoplankton was found as 87% at St. E4. It was noteworthy that contribution from nano+picoplanktonic crysophytes and green algae to total biomass of phytoplankton was significant at offshore. Satellite images of sea surface temperature indicated that an extensive area of the East/Japan Sea showed lower temperature ($<18\;^{\circ}C$) but the enhanced Chi a patch was confined to a narrow coastal region in summer, 1999. Exceptionally high flux of low saline water from the Korea/Tsushima Strait seemed to make upwelling weak in summer of 1999 in the study area. Results of comparisons among Chi a from SeaWiFS, HPLC and fluorometric analysis showed that presence of Chi b cause underestimation of Chi a about 30% by fluorometric analysis but overestimation by satellite data about 30-75% compared to HPLC data.

The Analysis of High Chlorophyll-a Concentration Patch in the North Marine Areas of East China Sea (동중국해 북부 해역의 엽록소 고농도 덩어리 분석)

  • Jeong, Jong-Chul
    • Journal of Environmental Impact Assessment
    • /
    • v.23 no.3
    • /
    • pp.220-226
    • /
    • 2014
  • This study investigated temporal-spatial and variations in Geostationary Ocean Color Imager (GOCI) products of parameters total suspended solids (TSS) and chlorophyll-a in the North Marine Areas of East China Sea.GOCI data were collected daily from February 2012 to December 2012. The higher chlorophyll-a values were observed during the investigation period. The relatively large increase in TSS and chlorophyll-a at the sampling stations coupled with typhoon events during the summer rainy period. The abnormal chlorophyll-a concentration was mainly driven by meteorological factors such as typhoon and rainfall in the coastal areas of Jeju and the North Marine Areas of East China Sea. The abnormal high chlorophyll-a concentration at the majority of the coastal stations indicate eutrophication of coastal waters, especially Red tide. The events such as eutrophication and abnormal high chlorophyll-a concentration may potentially influence outbreak of Red Tide, detected with GOCI parameters.

A Study on the Shape, Characteristic, and Investigated Design of Goryeo-Achungunsura-Jisun (고려 아청운수라 질손의 형태와 의미 규명 및 고증 디자인 연구)

  • Choi, Jeong
    • Journal of the Korean Society of Costume
    • /
    • v.63 no.1
    • /
    • pp.135-146
    • /
    • 2013
  • The purpose of this study is to investigate the meaning and possible shape of Goryeo-Achungunsura-jisun(高麗鴉靑雲袖羅質孫) through the details regarding its color, fabric, and pattern in the $13-14^{th}$ century writings and costume relics. Goryeo-Achungunsura-jisun was the summer dress coat that government officials wore during the Jisun feast of Yuan, and it was symbolic of the political strategy of Yuan as well as the excellent Goryeo fabric material, but no relics remain. During this period, Achung (dark blue)was the color that was used to dye silk, dress coats of upper class men, and background fabric of the embroidered official patch. And, the term, Yunsu (cloud sleeves), was probably sleeves with cloud pattern. The most typical cloud pattern in the 13 and the $14^{th}$ century was the 'flowing, gathering-headed cloud'. The Ra(silk gauze) weaving technique of Goryeo was developed rapidly in the $12^{th}$ century, and the quality of the Ra in the late Goryeo was good enough to be used for making the official's dress coat in the golden age of Yuan. According to the characteristic of jisun and man's formal-suit style in the Mongolian-Yuan, the possible styles for Goryeo-Achungunsura-jisun can be summarized as follows: a basic Mongolian gown with narrow sleeves and deep crossed diagonal opening, a Mongolian gown with waist pleats, the combination of half sleeved gown and long sleeved Mongolian gown. These styles would be made of delicate Goryeo Ra, cloud patterned sleeves, fabrics dyed in dark blue color, and shawl or embroidered patch ornaments for officials of Yuan, which was more simple than materials for Khan's Jisun to avoid rebellions.

Enhancement of Disease Control Efficacy of Chemical Fungicides Combined with Plant Resistance Inducer 2,3-Butanediol against Turfgrass Fungal Diseases

  • Duraisamy, Kalaiselvi;Ha, Areum;Kim, Jongmun;Park, Ae Ran;Kim, Bora;Song, Chan Woo;Song, Hyohak;Kim, Jin-Cheol
    • The Plant Pathology Journal
    • /
    • v.38 no.3
    • /
    • pp.182-193
    • /
    • 2022
  • Turfgrass, the most widely grown ornamental crop, is severely affected by fungal pathogens including Sclerotinia homoeocarpa, Rhizoctonia solani, and Magnaporthe poae. At present, turfgrass fungal disease management predominantly relies on synthetic fungicide treatments. However, the extensive application of fungicides to the soil increases residual detection frequency, raising concerns for the environment and human health. The bacterial volatile compound, 2,3-butanediol (BDO), was found to induce plant resistance. In this study, we evaluated the disease control efficacy of a combination of stereoisomers of 2,3-BDO and commercial fungicides against turfgrass fungal diseases in both growth room and fields. In the growth room experiment, the combination of 0.9% 2R,3R-BDO (levo) soluble liquid (SL) formulation and 9% 2R,3S-BDO (meso) SL with half concentration of fungicides significantly increased the disease control efficacy against dollar spot and summer patch disease when compared to the half concentration of fungicide alone. In field experiments, the disease control efficiency of levo 0.9% and meso 9% SL, in combination with a fungicide, was confirmed against dollar spot and large patch disease. Additionally, the induction of defense-related genes involved in the salicylic acid and jasmonic acid/ethylene signaling pathways and reactive oxygen species detoxification-related genes under Clarireedia sp. infection was confirmed with levo 0.9% and meso 9% SL treatment in creeping bentgrass. Our findings suggest that 2,3-BDO isomer formulations can be combined with chemical fungicides as a new integrated tool to control Clarireedia sp. infection in turfgrass, thereby reducing the use of chemical fungicides.

Occurrence of Insect Pests and Natural Enemies in Pear Orchard with Hairy Vetch (헤어리베치 재배과원에서 해충과 천적의 발생)

  • Choi, Yong-Seok;Whang, In-Su;Park, Deog-Kee;Choe, Gwang-Ryul
    • The Korean Journal of Pesticide Science
    • /
    • v.17 no.4
    • /
    • pp.448-453
    • /
    • 2013
  • We investigated the occurrence of major pests, 4 species of moths (Grapholita dimorpha Busck, Carposina sasakii Matsumura, Archips breviplicanus Walsingham, Adoxophyes orana Fischer von Roslerstamm), apple aphid (Aphis spiraecola Patch), two spotted spider mite (Tetranychus urticae Koch) and parasitoids in pear orchard with hairy vetch and cutting weeds in Yesan, Chungnam province during the flowering season and summer depression season of hairy vetch, in 2012 and 2013. The occurrence of 4 species of moths in hairy vetch plot and cutting weeds (major is finger grass, Digitaria sanguinalis, 80%) were little different but in case of apple aphid, the density in hairy vetch plot was just 95 aphids per stem at 20th June but low after then. The density of two spotted spider mite on pear leaf in hairy vetch plot was lower than in cutting weeds plot significantly. The number of parasitoids collected in hairy vetch plot during flowering season (May and June) were 398 and 798 in 2012 and 2013, respectively. The number of parasitoids collected in hairy vetch plot during summer depression season (July and August) were 114 and 172, respectively. But in cutting weeds plot, 9 and 22 in May and June, 8 and 5 in July and August. We didn't know either hairy vetch in pear orchard affected the occurrence of 4 species of moths, apple aphid and two spotted spider mite or not but was acted to be favorable for wasps, the natural enemies on the contrary. The improvement of chemical control systems through the selection of low chemicals to natural enemies with cover and green manure plants would turn effective pest management into a possibility.

Flying Aphid Population at the Horticultural Experiment Station, Suweon (원예시험장 주변의 진딧물)

  • Paik Woon Hah;Song Ki Won;Choi Seong Sik
    • Korean journal of applied entomology
    • /
    • v.13 no.1 s.18
    • /
    • pp.25-31
    • /
    • 1974
  • This survey was aimed to accumulate basic data of aphid population at the Horticultural Experiment Station at Suweon. The yellow pan traps were setted at five locations (Fig.1.), and ran from May 1 to October 31. 1970. About one hundred and twenty species of aphids were trapped, including 24 species of plant vims vectors. Of these, dominant species were as follows: (Asterisk shows virus vector) Aphid species No. of catches * Aphis spiraecola PATCH 2,635, * Aphis craccivora KOCH 2,377, * Myzus persicae SULXER 2,111, Capitophorus hippophaes javanicus H.R. LAMBERS 2,051, Anoecia fulviabdominalis SASAKI 1,480, * Aphis gossypii GLOVER 867, * Macrosiphum avenae FABRICIUS 859, Cervaphis quercus TAKAHASHI 692, * Lipaphis erysimi KALTENBACH 645, Pleotrichophorus chrysanthemi THEOBALD 489, The above 10 species consisted $76.5\%$ of total catches and the 24 vector species consisted $55.5\%$. The curve of the seasonal occurrence of flying aphids at Horticultural Experiment Station shows bimodal, typical for the temperate region. The total number of trapped aphids at the Station from May to September, 1970, were less than that of average yearly catches at the College of Agriculture from 1967 to 1970. Thi, low numbers at Horticultural Experiment Station may attribute to the frequent spraying of insecticides from Spring to Summer on growing crops there. But the aphids population increase suddenly in the middle of October. This might be resulted from cease of insecticide applications and migration of aphids from summer host to winter host plants.

  • PDF

Ecological Functions and Losses of Traditional Korean Village Groves

  • Lee, D.-W.;Park, C.-R.
    • The Korean Journal of Quaternary Research
    • /
    • v.18 no.2 s.23
    • /
    • pp.65-66
    • /
    • 2004
  • There have been groves, in many cases, along with hedgerows and remnant forests around a traditional Korean village. A village grove is very closely connected to the life of residents. Sometimes it was a holy place where important village festivals were held, and became a resting place for farmers, especially in sunny summer. As a matter of fact, it is noted that traditional Korean village groves had been fostered for many purpose as religion, Confucianism, scenery, sanitation, traffic guard, public security, agriculture, hunting, and military and public uses were included in Chosun Govemor General(1938). Village groves were usually located at the outlet of watershed inside which a village was built. In addition, village groves used to be established along part of mountain ranges, streams and streets. A unique type of village grove, called bibosoop was fostered especially where the outlet of watershed was largely opened. In other cases, it was placed where a part of mountain range was relatively low, or where village residents were likely to see ugly objects such as a huge cliff, stony upland with an unvegetated area and the like(Kim and Jang 1994). In a sense, a sheltebelt is a sort of bibosoop as it is a landscape element to complement places that are exposed to strong winds. However, it is comparable to other typical bibosoop that is situated at a topographically very specific zone of watershed. In this paper, we will address potential functions of Korean village groves from a perspective of modern landscape ecology and show current status of some remnants, based on preliminary surveys. A village grove functions as barrier or filter of objects such as water, nutrients, and other elements and habitat of wildlife (park et al. 2003, Lee 2004). The village grove slows down the flow of water and air, maintains soil moisture an hinders soil erosion, enabling cultivation of crops and bringing up creatures nearby. It contributes to enhancing biodiversity. Birds rest on shrubby and woody trees of the element. Presumably, other organisms may also inhabit the village groves and take advantage of it when those move from a forest patch to others. Emerging insects acclimate themselves in the shade of the green space before they fly to sunny air. Besides the village grove acts as a component of agroforestry system as leaf litter is shed from a grove to an asjacent agricultural area, and transformed into green manure(Lee 2004). By the way, many of the landscape elements were destroyed or declined in Koea during the past several decades. The losses have been parallel or linked to environmental degradation. Unfortunately, we have a little reliable data as for how many groves have disappeared in Korea until now. There has been no complete census on the village groves in Korea, and the viewpoints of survey were to a degree different depending on surveyors. So, it is difficult to analyze the temporal and spatial change of village groves. Currently, national inventory data of Korean village groves are available in three reports. We reviewed the locations of village groves and arranged those according to the present administrative units, DONG. With the limited data, we found that at least 484 of village groves were recorded in South Korea. Among all provinces, village groves were most in Gyeongsanbuk-Do Province and least in Chungcheongbuk-Do Province(Table 1). This is a preliminary report prepared while some quantitative data regarding functions and lossers of the village groves are being collected. More detailed data will be introduced in the near future.

  • PDF

Evaluation of the Qualitative Characteristics of Creeping Bentgrass(Agrostis palustris Huds.) Cultivars Using NTEP Data (미농무성 NTEP(Nat'l Turfgrass Evaluation Program) 자료를 이용한 Creeping Bentgrass(Agrostis palustris Huds.) 품종의 특성 평가)

  • Jang, Duk-Hwan;Joo, Young-Kyoo
    • Asian Journal of Turfgrass Science
    • /
    • v.21 no.1
    • /
    • pp.1-7
    • /
    • 2007
  • This study was initiated to evaluate the qualitative characteristics of creeping bentgrass(Agrostis palustris Huds.) cultivars for the climate In Korea through the NTEP(Nat'l Turfgrass Evaluation Program) data. 'L-93' showed the highest rating in overall mean visual quality. It was also the most prominent cultivar in seedling vigors, ground cover, and genetic color especially in summer. In case of turf texture, 'Penn A-1' and 'A-2' were the finest group, but the poorest group in cold tolerance. Leaf density and thatch accumulation were lower with 'Penncross', 'Pennlinks', 'Crenshaw', and 'L-93' as compared with 'Penn A'-type and 'G'-type cultivars. Resistance to moss invasion was greater with 'Penn A'-type and 'G'-type cultivars, but 'Penncross' was the least. These observations indicated that leaf density was considered to associate with the characters of turf quality, thatch accumulation and resistance to moss invasion. 'Penn A'-type cultivars were highly resistant to snow mold. Greater resistance to brown patch was associated with 'Penn A' and 'Penncross'. Higher resistance to pythium blight was found with 'Penncross' and 'Pennlinks'. 'L-93' showed higher resistance to dollar spot, but not to pythium. Therefore, these results demonstrated that turf maintenance program for the new bentgrass cultivars should be different from a conventional management for the cultivar of 'Penncross'.

Effects of Typhoon and Mesoscale Eddy on Generation and Distribution of Near-Inertial Wave Energy in the East Sea (동해에서 태풍과 중규모 소용돌이가 준관성주기파 에너지 생성과 분포에 미치는 영향)

  • SONG, HAJIN;JEON, CHANHYUNG;CHAE, JEONG-YEOB;LEE, EUN-JOO;LEE, KANG-NYEONG;TAKAYAMA, KATSUMI;CHOI, YOUNGSEOK;PARK, JAE-HUN
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
    • /
    • v.25 no.3
    • /
    • pp.55-66
    • /
    • 2020
  • Near-inertial waves (NIW) which are primarily generated by wind can contribute to vertical mixing in the ocean. The energetic NIW can be generated by typhoon due to its strong wind and preferable wind direction changes especially on the right-hand side of the typhoon. Here we investigate the generation and distribution of NIW using the output of a real-time ocean forecasting system. Five-year model outputs during 2013-2017 are analyzed with a focus on cases of energetic NIW generation by the passage of three typhoons (Halong, Goni, and Chaba) over the East Sea. Calculations of wind energy input (${\bar{W}}_I$), and horizontal kinetic energy in the mixed layer (${\bar{HKE}}_{MLD}$) reveal that the spatial distribution of ${\bar{HKE}}_{MLD}$, which is strengthened at the right-hand side of typhoon tracks, is closely related with ${\bar{W}}_I$. Horizontal kinetic energy in the deep layer (${\bar{HKE}}_{DEEP}$) shows patch-shaped distribution mainly located at the southern side of the East Sea. Spatial distribution of ${\bar{HKE}}_{DEEP}$ shows a close relationship with negative relative vorticity regions caused by warm eddies in the upper layer. Monthly-mean ${\bar{HKE}}_{MLD}$ and ${\bar{HKE}}_{DEEP}$ during a typhoon passing over the East Sea shows about 2.5-5.7 times and 1.2-1.6 times larger values than those during summer with no typhoons, respectively. In addition, their magnitudes are respectively about 0.4-1.0 and 0.8-1.0 times from those during winter, suggesting that the typhoon-induced NIW can provide a significant energy to enhance vertical mixing at both the mixed and deep layers during summer.