• Asian Journal of Turfgrass Science
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• v.19 no.2
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• pp.103-113
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• 2005

This study was conducted to improve the green up of zoysiagrass(2. japonica) and cool-season grass($80\%$ Kentucky bluegrass+$20\%$ Perennial ryegrass) during early spring in Korea. Treatments fur zoysiagrass were control, Polyethylene film, Black screen, Black screen+polyethylene film, Green screen+polyethylene film, Polyethylene film+Black screen, Polyethylene film+Green screen, low mowing height(1.5-2cm) and homing. For cool-season grass, non-punched Polyethylene film, punched Polyethylene film treatments were included. Application dates of covering with Polyethylene film were Feb. 22, Feb. 28, March 7, and March 14. Green up was evaluated by visual color rating. The results are as follows; 1. The best method for improving green up of zoysiagrass were Polyethylene film and optimal covering day for zoysiagrass was on Feb. 22. 2. Low mowing height(1.5-2cm) and burning of zoysiagrass showed the faster greening 1$\sim$weeks before than control. .3 Non-punched Polyethylene film covering was best to improve green up of cool-season grass. More time of covering time with cool-season grass induces rapid green up.

• Asian Journal of Turfgrass Science
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• v.26 no.2
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• pp.102-109
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• 2012

Commercial formulation of fungicides was studied in the golf course for evaluation against Typhula incarnata causal agents of gray snow mold. Efficacies of fungicides application, fungicide mixture, fungicides applied method (irrigation and spray) and fungicides applied time (early fall and late fall) were evaluated for their influence on the chemical control of gray snow mold of turfgrass during the winter season in Yongpyeong golf course, Korea. Unsprayed control has significantly more disease severity than three fungicides (azoxystrobin, propiconazole, and tebuconazole) were applied to field plots. Effect of three fungicides was over 80% with control value for controlling gray snow mold on Kentucky bluegrass and creeping bentgrass species. Effect of fungicide mixture with different family groups had an over 93% control value of gray snow mold on Kentucky bluegrass species. It was not significantly difference in fungicidal effect according to applied method (irrigation and spray) with azoxystrobin on Kentucky bluegrass and creeping bentrasss species. Effect of fungicides applied time was a significantly difference on disease control by tebconazole early fall spray.

• Asian Journal of Turfgrass Science
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• v.21 no.2
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• pp.127-135
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• 2007

Korea and Japan hosted the FIFA World Cup Soccer Game in 2002. Ten stadiums had been built and more than 30 soccer grounds for practice were renovated in Korea. Sport fields in both countries had problems on cool-season turfgrass growth and quality by summer decline during humid and warm climate especially followed by intensive uses. We measured the effects of air-flow system, which is designed to optimize rootzone soil gas and moisture levels to promote the growth and maintenance turfgrass. This experiment was carried out to verify the effects of the system on soil gas exchange, ground resilience, and turfgrass recovery in turfgrass rootzone. Within 1 or 2hr of operation of the system, rootzone soil gas ($CO_2$, $O_2$) levels returned to natural atmospheric levels completely Soil $CO_2$ levels began to decrease within the first 10 min of operation of the system. The levels were reduced from 1.3 to 0.06% after 30 min, and natural atmospheric levels within 1 hr. When the system was turned off, $CO_2$ levels increased to 0.36% and 0.7% after 5 and 20 hr, respectively. The application of the system did not affect the resilience of turf surface after traffic treatments. Higher traffic treatment resulted in higher surface resilience especially in zoysiagrass plots. Operation of the system had a significant beneficial impact on turf recovery by increased root dry wight and improved turf quality, as compared with the non-operated check plots.

• Asian Journal of Turfgrass Science
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• v.23 no.1
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• pp.35-44
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• 2009

This study was carried out to examine the growth performance of 4 species of cool-season grasses and 4 species of zoysiagrasses under salt injury in Seo-san reclaimed area. Grasses were grown on the plots with capillary water interruption layer (WCWIL) and without capillary water interruption layer (WOCWIL) soil systems. Cool-season grass and seeding-type zoysiagrass plots were seeded on 6 Jun, 2006. Vegetative zoysiagrass 'Junggi' was established by sprigging and 'Senock' and 'Millock' were plugged. Electric conductivities of irrigation water (ECw) ranged from 0.28 to $3.3\;dS{\cdot}m^{-1}$. Electric conductivities (ECe) of the soil with capillary water interruption layer and without capillary water interruption layer ranged from 0.55 to $9.4\;dS{\cdot}m^{-1}$ and from 1.84 to $9.4\;dS{\cdot}m^{-1}$ respectively. Leaf color, turf quality, coverage rates, and growth rates were rated visually for 2 years. Zoysiagrass 'Junggi', creeping bentgrass, zoysiagrass 'Senock' and 'Millock' showed acceptable growth at salty fairway condition, while Kentucky bluegrass, perennial ryegrass, Kentucky bluegrass mixed with perennial ryegrass, and seeded zoysiagrass 'Zenith' showed establishment rates below 70%. These results will be useful when choosing turf grass species and cultivars for the golf courses in reclaimed land area.

• Asian Journal of Turfgrass Science
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• v.16 no.1
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• pp.1-10
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• 2002

The influence of calcium on the growth of creeping bentgrass 'Penn-Al', perennial ryegrass 'Palmer II', Kentuckuy bluegrass 'Nassou' and tall fescue 'Boonsai 2000' in greenhouse was investigated. Creeping bentgrass 'Penn-A1', Kentucky bluegrass 'Nassou' and tall fescue 'Boonsai 2000' at Ca 4.0 me/L, and perennial ryegrass 'Palmer II' at Ca 2.0 me/L showed the best shoot growth. Creeping bentgrass 'Penn-A1', perennial ryegrass 'Palmer II' and Kentucky bluegrass 'Nassou' at Ca 1.0 me/L, and tall fescue 'Boonsai 2000' at Ca 4.0 me/L showed the best root growth, and there was little or no difference between different Ca concentrations. Creeping bentgrass 'Penn-Al' and Kentucky bluegrass 'Nassou' at Ca 4.0 mea, and perennial ryegrass 'Palmer II' at Ca 1.0 me/L had the highest number of tillers, and tall fescue 'Boonsai 2000' at Ca 4.0 me/L had the highest, but there was no difference between different Ca concentrations. As application rate of Ca concentration became higher, the concent of Ca in plant tissue increased, while the content of Mg in plant tissue decreased, and the content of Fe in plant tissue increased to Ca 4.0 me/L. The Ca treatment had not effect on N, p, K, and Zn of tissue content. The wick pot applied will be to research of plant nutrition in future because utilization of wick pot has an excellent precision and convenience.

• Asian Journal of Turfgrass Science
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• v.19 no.2
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• pp.151-160
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• 2005

Research was initiated to investigate seasonal turf quality under a sand-based 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 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 quality, while perennial ryegrass (PR) the poorest. Intermediate turf quality 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 other CSG. Results demonstrate that KB was the best and PR the worst among CSG grown in a sand-based USCA soil system.

• Asian Journal of Turfgrass Science
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• v.17 no.2_3
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• pp.67-73
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• 2003

A series of studies was conducted during 2 years to investigate the effect of transplanting time and turfgrass species on turf establishment rate of sod for 2002 World Cup Soccer ground construction. The required period of rooting and turf growth for acceptable soccer playing quality on transplanted sod from nursery was tested to collect data for the project authorities of hosting cities and construction companies who were involved in World Cup stadium project. Transplanting time significantly affects on rooting-potential of sod on cool season grass and zoysiagrass, but those effects differently showed by turfgrass species. The enough nursing period for the ground established by Zousiagrass should be secured with proper transplanting time. And the thermal insulation on the turf canopy with other maintenance during Winter should improve the early rooting on zoysiagrass. The sod contained Kentucky bluegrass (85％＋15％ perennial ryegrass, seed wt. basis) showed relatively slow at the early growth and rooting-potential of root, but the potential resulted higher than that of perennial ryegrass turf (85％＋15％ Kentucky) under longer nursing period. Kentucky bluegrass has one of the most strong resistance against environmental stresses, but intensive maintenance practise should be required when the turf transplanted during summer season. Higher mixture rate of perennial ryegrass sod has a rapid root growth compare with other turfgrass species. The rate provided a benefit to an early establishment of turf ground followed by a proper maintenance practise. For the completion of World Cup soccer ground construction for 2002, the most suitable time for sod transplanting in 2001 was March to May or mid Sept. to early Oct. by delayed architect construction schedule.

• Weed & Turfgrass Science
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• v.6 no.4
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• pp.333-344
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• 2017

This study was conducted to examine the effect of cool-season grass overseeding on the green period, turf quality and density in zoysiagrass lawn. Treatments were perennial ryegrass (PR) overseeding ($60g\;m^{-2}$) on medium-leaf type zoysiagrass, Kentucky bluegrass (KB) overseeding ($20g\;m^{-2}$) on medium-leaf type zoysiagrass and narrow-leaf type zoysiagrass, and no overseeding on medium-leaf type zoysiagrass. Overseeding of KB or PR effectively provided quality improvement of zoysiagrass lawn by extending green-period about one month in spring and two months in fall season. PR overseeding showed quick green cover within 2-3 weeks but decreased the quality of overseeded zoysiagrass lawn during the summer season. Whereas, KB overseeding showed slow green cover taking two to three month after seeding but provided stable and good turf quality throughout the years. KB or PR overseeding significantly increased the turf density of zoysiagrass lawn except the period of summer depression of PR. The ground coverage of cool-season grasses ranged from 30 to 80% with considerable seasonal variation. As a result, KB and PR have their strengths and weaknesses as an overseeding material. Thus, the use of KB and PR as a mixture would provide better overseeding performance in zoysiagrass lawn.

• Korean Journal of Weed Science
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• v.30 no.4
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• pp.323-329
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• 2010

Methiozolin (5-(2,6-difluoro-benzyloxymethyl)-5-methyl-3-(3-methyl- thiophen-2-yl)- 4,5-dihydro-isoxazole) is a new turf herbicide in isoxazoline chemistry. The herbicide controls grass weeds and has a high safety to various cool and warm season turfgrasses. This paper describes basic chemical, biological, and regulatory information of methiozolin.

• Asian Journal of Turfgrass Science
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• v.22 no.1
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• pp.75-84
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• 2008

This study was carried out to examine the effects of cornstarch-based absorbent polymer (CAP) on the growth of cool season turfgrasses in sand-based soil mixture. Kentucky bluegrass + perennial ryegrass mixtures seeded at May 18 in 2006 on sand-based soil mixture. Sand + peat (5%, v/v), sand + CAP $20g{\cdot}m^{-2}$, sand + CAP $20g{\cdot}m^{-2}$ + peat (5%, v/v), and sand + CAP $40g{\cdot}m^{-2}$ + peat (5%, v/v) mixtures were compared. Ground coverage of sand + CAP $20g{\cdot}m^{-2}$ + peat (5%, v/v), and sand + CAP $40g{\cdot}m^{-2}$ + peat (5%, v/v) treatments showed 50% at a month after seeding. But the coverage of sand + peat (5%, v/v), sand + CAP $20g{\cdot}m^{-2}$ resulted in 36.7%. Mixing of CAP with sand was considered to be efficient method for increasing ground coverage as much as peat. Dry weight of turfgrass tiller at sand + CAP $20g{\cdot}m^{-2}$ + peat (5%, v/v), and sand + CAP $40g{\cdot}m^{-2}$ + peat (5%, v/v) were also significantly higher than sand + peat (5%, v/v), sand + CAP $20g{\cdot}m^{-2}$ mixtures at a month after seeding. Soil water retention at the sand + CAP $20g{\cdot}m^{-2}$, sand + CAP $40g{\cdot}m^{-2}$ + peat (5%, v/v) mixing were lower than sand + peat (5%, v/v) and sand + CAP $20g{\cdot}m^{-2}$ + peat (5%, v/v) during the dry periods. From the results, the mixing of CAP with sand is useful to increased ground coverage of kentucky bluegrass and perennial ryegrass.