• Weed & Turfgrass Science
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• 제4권4호
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• pp.383-389
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• 2015

The use of zoysiagrass (Zoysia japonica Steud.) in the transition zone is limited because of a lack of cold hardiness although zoysiagrass has many advantages compared to other warm-season and cool-season grasses. Late-fall N fertilization is often applied for darker green color of turfgrass in early spring and more extensive root growth without rapid top growth. The objective of the study was to evaluate the effects of late fall N application and turf cover for zoysiagrass spring green-up. Clear polyvinyl chloride (PVC) film was used for turf cover. The amount of N applied were 5 and $10g\;N\;m^{-2}$ for the low and high N rate treatments, respectively. Covered zoysiagrass had greater turfgrass color and quality in early spring than non-covered zoysiagrass. The high N rate had 0.6 to 2.3 greater turfgrass quality than the low N rate on 7 of 9 rating dates. Slow-release N as late fall fertilization is more effective for turfgrass color and quality than fast-release N in spring. Turf cover could reduce the period of yellow zoysiagrass, and the earlier time of spring green-up could be advanced by increasing turfgrass quality and growth of zoysiagrass.

• 한국조경학회지
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• 제33권5호통권112호
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• pp.83-93
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• 2005

Research was initiated to investigate turf performance under USGA soil system. USGA system 45 centimeters deep was built with rootzone layer, intermediate layer, and drainage layer. Six turfgrass entries were comprised of 3 blends and 3 mixtures from cool-season grasses (CSG). Turfgrass color and quality ratings were best in spring and fall, especially early May to early July and late August to early November. Kentucky bluegrass (KB) consistently produced the greatest performance, while perennial ryegrass (PR) the poorest. Intermediate turf performance between KB and PR was observed with tall fescue (TF). Among CSG mixtures it increased with KB but decreased with PR. There were considerable variations in summer turf Performance. No summer drought injury was found in KB and TF. However, PR showed poor performance through summer as compared with others. Among mixtures, it decreased with PR. It was suggested that PR mix in less than $20\%$ in the mixtures to have an acceptable quality in summer. Cultural intensity also affected it. With lowering mowing height, KB of rhizomatous-type in growth habit kept good quality, while PR and TF with bunch-type in growth habit poor quality. Mowing quality was greatly different among CSG. KB produced clean-cut surface, but PR unclean one. If had an intermediate mowing quality between KB and PR. A great difference in green color retention was observed among CSG. The longest CSG was PR that kept green for 339 days, while the shortest one TF for 267 days. KB continued to keep green for 290 days. The mixtures kept green in color for 292 to 315 days, depending on turfgrass mixing intensity. The greater the PR in content, the longer the green color duration. These results demonstrate that KB was the best and PR the worst among CSG grown in USGA system under a domestic climate, in regards of turf quality, color, mowing quality, summer turf performance and green color duration. KB and TF are most adequate for high-maintenance and low-maintenance area, respectively. In case of mixtures for high-quality turf, it was desirable to use KB-based mixture with PR of below $20\%$ in seeding rate.

• 아시안잔디학회지
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• 제11권2호
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• pp.97-104
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• 1997

The objective of this study was to observe the differences in growth of creeping bentgrass turf to 'polymer coated urea fertilizer' and 'uncoated urea fertilizer', and to analyze durability of fertilizer effect with the 'polymer coated urea'. The experiment was initiated on June 3, 1996, at the Iowa State University Horticulture Research Station, north of Ames, Iowa. The experiment was conducted on an area of 'Penneagle' Creeping bentgrass(Agrostis palustris) maintained at fair-'way mowing height (1.3cm). The study was repeated at the same arrangement beginning on July 25, 1996. Visual quality data, clipping fresh and dry weight, and nitrogen(N) content in the clippings were taken weekly. Quality of the turf increased with increasing N rate. While quality ratings were higher for turf receiving polymer coated urea than for turf receiving uncoated urea at several times following treatment, but not significant. Fresh and dry clipping weights were quite variable during the trial. Visual quality rating and clipping yields improved with increasing rates of N but these differences were not statically significant between polymer coated and uncoated urea treatment. The durability of fertilizer efficiency in polymer coated urea was not last longer compare with uncoated urea from two weeks after treatment. Higher rates of N application increased the concentration of N in tissue but no significant differences between turf plots receiving polymer coated and uncoated urea. Key words: Polymer coated urea, Creeping bentgrass, Fertilizer, Turfgrass.

• 원예과학기술지
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• 제33권3호
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• pp.340-348
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• 2015

Mowing turfgrasses, especially fast growing species like perennial ryegrass, is one of the most time and money consuming tasks of their management. Trinexapac-ethyl (TE) is a popular plant growth regulator used to reduce mowing requirements, improve stress tolerance, and enhance turf quality. This study was conducted to investigate the effect of TE rate and frequency of applications on growth response and traffic tolerance of perennial ryegrass. The experiment was a split-plot laid out in a randomized complete block (RCB) design with three replications. TE was applied to main plots at 0.00, 0.25, and $0.50kg\;a.i.\;ha^{-1}$. Application pattern included an initial application, followed by two sequential applications at 6-wk intervals. Traffic treatment was applied to subplots with a cleated roller. Results demonstrated that TE consistently reduced vertical shoot growth, clippings dry weight, with maximum growth reduction of 59% and 65%, for 0.25 and $0.50kg\;a.i.\;ha^{-1}$, respectively, occurring at 2 weeks after initial TE treatment (WAT). Traffic also dramatically reduced vertical shoot growth and clippings dry weight. Overall, quality of perennial ryegrass was enhanced by sequential TE applications, however, turf quality and surface coverage reduced greatly under traffic, regardless of TE treatment. Total chlorophyll, chlorophyll a and chlorophyll b and total carbohydrates (TC) contents were also positively influenced following sequential TE application. Our results indicated that TE reduces mowing frequency and enhances turf quality rather than influencing traffic resistance.

• 아시안잔디학회지
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• 제26권2호
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• pp.116-122
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• 2012

본 연구는 규산과 칼리 시용이 골프장 그린용 크리핑 벤트그래스 잔디의 생육과 품질 그리고 내답압성에 미치는 영향을 알아보기 위해 실시되었다. 먼저 규산과 칼리 시용에 따른 잔디반응을 살펴보기 위해서 필드조건에서 잔디품질, 뿌리길이, 잔디밀도와 건물중을 평가하였다. 다음으로 답압빈도에 따른 크리핑 벤트그래스의 잔디생육(뿌리길이, 잔디밀도, 건물중)과 잔디품질 및 토양경도를 조사하였다. 마지막으로 30일간의 답압처리조건에서 규산과 칼리의 내답압성 시비효과를 평가하였다. 규산 및 칼리 처리에 따른 잔디뿌리생육에 있어서 규산을 증가함에 따라 뿌리길이가 증가하였다. 크리핑 벤트그래스의 답압빈도에 따른 잔디품질은 1일 2회 처리구가 가장 우수하였으며, 7회 처리구는 무답압 처리구보다 우수하였다. 그러나 15회 이상 답압 처리구는 잔디품질이 월등히 저하하였다. 30일간의 답압처리시 규산 및 황산칼리의 시비효과는 잔디품질 향상 및 뿌리생육 증진효과가 있었다. 규산과 칼리를 처리하였을 때 잔디품질이 대조구보다 각각 6.38%, 10.25% 상승하였으며 규산과 칼리를 혼용 살포하였을 때 가장 잔디품질이 좋았다. 잔디 뿌리길이는 규산을 살포하였을 때 가장 길었으며 대조구보다 11.4%가 길었다. 따라서 답압이 예상되는 골프장 그린용 벤트그래스에서 잔디의 내답압성 증진을 위해서는 규산과 칼리의 시비가 효과적이었다.

• 한국환경복원기술학회지
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• 제7권3호
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• pp.56-63
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• 2004

This study was carried out to find out the effect of by-product gypsum(phosphogypsum, PG) application on enhancement of turf quality. For the first experiment, 10 ton $ha^{-1}$ PG was applied to 1m${\times}$10m (width${\times}$length) Plots with 4 replicates on a sloping area of fairway where turf(Zoysia japonica L.) was grown. Both top- and sub-soil samples were collected before and after treatment and were analyzed for pH, EC(e1ectrica1 conductivity), Ca and Mg contents. At the same time when soil samples were collected, specific color difference sensor value(SCDSV) that represented chlorophyll contents, fresh and dry weight of the turf were determined to find out the effect of PG treatment on turf growth. SCDSV of turf from PG treated plots measured at 98 and 147 days after treatment were significantly higher than those from control. Considering higher fresh and dry weight of leaf per unit area from PG treated plots than that from control, it was concluded that the elevated Ca and S level of the PG treated plots resulted in vigorous leaf growth of turf. For the second experiment 2, 5 and 10 ton $ha^{-1}$ PG were applied to 1m${\times}$10m(width${\times}$length) Plots with 3 replicates at a closer location as was used for the first experiment to find out the appropriate PG application rate. Before and after treatment soil and plant samples were collected and were analyzed by the same way as the first experiment. The pH of all the soil samples collected from PG treated plots at 38 days after treatment was lower than that from control. This trend changed as time passed. However, the pH of the soil from 10 ton $ha^{-1}$ PG treated plot was lower than that from control during the whole period of the second experiment. SCDSV, fresh and dry weight of leaf from PG treated plots at all 3 rates were higher than those from control for the second experiment. PG application to turf will be beneficial for both mass consumption of by-product gypsum and enhancement of turf quality.

• 아시안잔디학회지
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• 제18권3호
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• pp.119-128
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• 2004

This study was conducted to analyze the effect of roof membrane on light environment that influence on turfgrass growth under domed stadium. Roof structure on experimental plot was constructed with PTFE and PE same as Busan Asiad Main Stadium. Tested turfgrass species were combinations of cool-season grasses(Kentucky Bluegrass, perennial ryegrass, $KBG80+PR20\%,\;KBG33+PR33+Fine fescue33\%)$ and warm-season grasses(zoysiagrass, 'An-yang middle-leaf, 'Zenith', Bermudagrass) established with seeding or sodding. The experimental set-up and research work were initiated November 1999 and finished on August 2000 at near Busan Asiad Main Stadium. By the result of computer simulation of daylight radiant energies on the turf surface were lower than needs of normal sport turf growth. The shortage of radiant resulted pest infection on cool-season grass mixture compared with warm-season. But turf color and density showed the best results on Kentucky bluegrass or its mixture plot. Over all the results showed that the best quality of turfgrass growth was occurred on full sun area, and the next was under PTFE membrane. The application of artificial lighting system may increase the turfgrass growth under domed stadium(partially) covered with roof membrane.

• Weed & Turfgrass Science
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• 제2권3호
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• pp.292-297
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• 2013

Winter turfgrass injury is one of the critical problems of many golf courses in Korea. Turfgrass loss from freezing injury due to low temperature leads to many types of damages including weed invasion, increased herbicide cost, increased soil erosion, and expensive re-establishment. Although Kentucky bluegrass (Poa pratensis L.) which is the most widely used among cool-season grasses in Korea is well known as cold tolerance species, freezing injuries to Kentucky bluegrass during winter are often found. Protecting the turfgrass crown is necessary to recover from low temperature stress in winter because shoots and roots can be recovered from the crown. Turf covers may protect the crowns from direct low temperatures and desiccation. Six different turf covers were installed to cover Kentucky bluegrass during a period of low temperatures. Turf covers had positive effects for spring green-up of Kentucky bluegrass based on the study. Applying any type of turf covers on Kentucky bluegrass resulted in an increase average and minimum temperature compared to the uncovered plot. Among turf covers, clear PVC film without holes produced the longest root length and the highest turfgrass quality.

• 한국환경복원기술학회지
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• 제8권5호
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• pp.10-18
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• 2005

The research was carried out to define the morphological and growth characteristics of Poa pratensis L.(Kentucky bluegrass) 'Sewon' in native to Korea. Poa pratensis 'Sewon' was collected at the terrace land on the river in Guiman-ri, Cheongcheon-myeon, Goesan-gun, Chungcheongbuk-do on May 5, 1995. The collected Poa pratensis 'Sewon' was grown under non-mowing naturally growing condition. The morphological characteristics of Poa pratensis 'Sewon' are as follows. : The height of plant was 21.6cm but was increased to 33cm at the flowering time. The height of first node from the base was 5.0cm and the length and width of leaf were 9.6cm and 4.1cm, respectively. The length of inflorecences was 37.8cm and the length of a spike was 7.3cm. Based on these morphological characteristics, Poa pratensis 'Sewon' was defined to dwarf~medium and coarse texture type Kennturky bluegrass. 1 to 9 scale of visual quality, visual color and visual density were measured. Poa pratensis 'Sewon' showed best turf qualities among native Kentucky bluegrasses. In spring and fall growing season, Poa pratensis 'Sewon' were measured to be excellent performances for turf qulities similar to foreign excellent quality cultivars such as Midnight, Nuglade and Brilliant Kentucky bluegrasses. But turf quality of Poa pratensis 'Sewon' decreased by plant disease according to temperature increase in summe compared to foreign excellent quality cultivars. So, Poa pratensis 'Sewon' should be improved of disease tolerent quality by incessant breeding work in order to compete foreign excellent quality cultivars.

• 아시안잔디학회지
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• 제5권1호
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• pp.1-10
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• 1991

The purpose of the experiment was to determine the effect of nitrogen sources (urea, ammonium sulphate, ammonium nitrate) and potassium sources (potassium chloride, potassium sulphate) on the growth and quality of Zoysia japonica Steud. This experiment was conducted at Seoul City University turf field from 1988 to 1989. The results of this experiment were summarized as follows; 1. Urea and Ammonium sulphate resulted in superior clipping yield compared to ammonium nitrate. The growth of rhizome and stolon increased significantly with urea forms, but ammonium sulphate treated plots exhibited the highest the growth rate of root. 2. Ammonium sulphate showed best turf color rating while ammonium nitrate resulted in the poorest. Prolongation of the green period showed longer in ammonium sulphate and urea treated plots than ammoium nitrate. 3. Urea and ammonium sulphate exhibited superior visible quality and shoot density compared to ammonium nitrate. 4. The uptake of mineral nutrient showed the highest concentration with urea plots. Surface soil pH was allowed to become slightly acid with the ammonium sulphate and potassium sulphate treatments, while the application of N and K sources did not cause significant differences in mineral element content in soil.