• Asian Journal of Turfgrass Science
• /
• v.21 no.1
• /
• pp.9-21
• /
• 2007

Research was initiated to examine establishment efficiency of zoysiagrass by plugging. Zoysiagrass is known to be a slowly establishing turfgrass species. Properly-treated zoysiagrass seed can speed up the establishment rate, while initial irrigation practice is intensively required after seeding. A planting method with small plugs($2.5{\times}2.5cm$) from seeding can overcome initial watering requirement. Establishment speed, however, can vary with planting dates, planting spaces, and plastic film cover in early stage. Establishment characteristics were investigated for two years by planting dates that were April 5, May 18, July 13, August 24 and October 29 in 2004 and April 6 in 2005. They were also compared with three different spaces($20{\times}20,\;25{\times}25,\;and\;30{\times}30cm$) and three different fertilizer levels(15, 30, and $45g\;N{\cdot}m^{-2}$). Ground coverage reached to 90% in plugs of 'Zenith' zoysiagrass planted on April 5. It increased suddenly in period of July to August, resulting in about 50% of full establishment rate. Establishment rates were significantly faster over 9% in plugs spaced at $20{\times}25cm$ than in those at $30{\times}30cm$. No significant differences were observed on the stolen number and stolen length in the study. Survival rate in zoysiagrass plug was over 90% at all plantings. These results demonstrated that zoysiagrass establishment using small plug from seeding is considered to be a safe and efficient method.

• Weed & Turfgrass Science
• /
• v.3 no.4
• /
• pp.347-353
• /
• 2014

This study was conducted to investigate the effects of composted liquid manure (CLM) on soil properties and turf quality of zoysiagrass. The CLMs were produced at 5 facilities for livestock excretions treatments located in Cheongwon, Gunwi, Iksan, Nonsan, and Yeoju in Korea, respectively. Field experiments were conducted at 5 golf courses and a sod farm located near each facility for livestock excretion treatments. Chemical fertilizer (CF) with N at $12g\;m^{-2}year^{-1}$ and CLMs were applied four times, respectively. The constituents of the different CLMs were variable based on when and where the fertilizer was produced. Soil K content significantly increased when the soil was treated with CLMs. The soil treated with CF showed a higher content of total P than that treated with CLM. CF and CLMs treatments significantly increased the turf color index compared with control. Tiller density and shoot dry weight of fertilized plots were also higher than those of non-fertilized plots. However, there was no significant difference in turf color index and tiller density among plots treated by CLMs or CF. The results of this study demonstrated that CLMs could be a substitute for CF.

• Asian Journal of Turfgrass Science
• /
• v.13 no.1
• /
• pp.21-28
• /
• 1999

The seeds of Zoysiagrass (Zoysia japonica Steud.) were soaked with GA3 50 ppm and primed with CaCl2 at -1.0 MPa for 4days at 23$^{\circ}C$ to identify presoaking and priming regimes that may improve germination in saline condition and with PEG 8000 at high temperature. Presoaked, primed, and untreated seeds were then germinated at 30 and $35^{\circ}C$. NaCl salinity stress consistently decreased the rate of germination of zoysiagrass seed. GA3 or CaCl2 alleviated the inhibitory effect of salinity on germination. However, total percent germination (G) and T50 of untreated control seeds significantly decreased and prolonged at $30^{\circ}C$ and $35^{\circ}C$ as NaCl salinity stress increased. Presoaked seeds with GA3 50 ppm for 4 days at $23^{\circ}C$ had significantly higher germination and lower T50 than untreated or primed with CaCl2 at -1.0 MPa for 4days at $23^{\circ}C$m and overcame the inhibitory effect of germination derived from PEG 8000. In addition, presoaked seed had higher, faster, and more uniform germination than untreated seeds after sowing in growing media in greenhouse.

• Korean Journal Plant Pathology
• /
• v.11 no.3
• /
• pp.278-281
• /
• 1995

An isolate of Rhizoctonia solani AG 2-2(IV) from zoysiagrass was examined on development of its teleomorph by the modified soil-on-agar culture method. The most effective growth medium for sporulation was Czapek's 1/2 agar medium added with yeast extract and peptone. The characters of teleomorph of R. solani AG 2-2 (IV) are as follows. Hymenia developed on soil surface after the development of vegetative hyphae. Basidia were barrel-shaped, short clavate or obovate and were 11.4~17.9$\times$7.1~11.4 ${\mu}{\textrm}{m}$ (mean : 15.1$\times$9.0 ${\mu}{\textrm}{m}$) in size. Sterigmata were horn-shaped and slightly bent to the inner side and 4.3~18.6 ${\mu}{\textrm}{m}$ (mean : 10.3 ${\mu}{\textrm}{m}$) in size. Two to four sterigmata developed on each basidium. Basidiospores were obovate, ellipsoid to oblong-ellipsoid, hyaline, smooth, thin walled, with an apiculus, and 3.6~10.4$\times$2.9~5.7 ${\mu}{\textrm}{m}$ (mean : 7.8$\times$4.4 ${\mu}{\textrm}{m}$) in size.

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

• Asian Journal of Turfgrass Science
• /
• v.3 no.2
• /
• pp.89-94
• /
• 1989

Research was conducted to obtain t he optimum treatment Of sodium hypochlorite(NaOC I) at various temperatures in t he seed scarification for stimulating germination of zoysiagrass (Zocysia Japonica Steud ) seed. Morphological changes of seed coat were also examined by scanning electron micros cop(SEM). l. Differences in temperature of scarification with 2 .4% NaOCI showed little influence on promoting germination of seeds but seeds treated with 1% solution at l5˚C germinated less than that of higher temperatures. The promotion effect of 4% solution on germination was diminished when seeds were treated for 8 hours of more. The most favorable seed scarification unaffected hy temperature for enhancing germination was 4-6hours treatment at 4% solution in fresh seeds. 2. $GA_3$, treatment did not enhance germination of water-pretreated control seeds hut germination of seeds pretreated with NaOCI l was increased additional 10% or more hy$ GA_3$, Water pretreated control seeds treated with 50 mM hydrogen peroxide(H'O )germinated about 44%. In NaOCI treated seeds. $H_2$$O_2$ treatment increased germination additional l 0% or more. 3. NaOCI l and KOH treatment softened the seed coat and formed the pores hy removing the scab-like thikenings attached to the seed surface. These results suggest that the modes of action of NaOCl in the promotion of seed germination reside in it increase of the permeability of the seed coat, and in the provision of additional oxygen to the seed.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.31 no.3
• /
• pp.107-113
• /
• 2003

Ecological control can contribute to the sustainibility of vegetation management systems by reducing the input currently derived from non-renewable fossil energy sources. The use of turfgrass mixtures is an important tool in turf management. Turfgrass mixtures of two or more compatible and adapted species provide improved tolerance to pest and environmental stress, more so than monostands. The objectives of this study were to evaluated turf insects, pests and zoysia large patch control by turgrass mixtures. In April 2001 and 2002, plots were inoculated with 50g of Rhizoctonia solani AG2-2LP inoculum. Inoculum were treated within a 29cm diamater circle at Zoysia japonica, Zoysia japonica, Poa pratenis, or Festuca arundinacea mixtures. After four weeks, disease severity in each plot was determined. plot area visual ratings were assessed visually on a linera 0 to 100%. In August 2001 and October 2002, turf insects and pests in each plot were investigated in 10cm deep soil cores with 8cm diameters using hole cut. Zoysia large patch affected zoysiagrass monostands more severly than zoysiagrass and cool-season turfgrasses mixtures. It was suggested that the barrier effect of cool-season turfgrass suppressed zoysia large patch in the mixture of zoysiagrass and cool-season turfgrasses. Also, warm-season and cool-season turfgrasses mixtures suppressed insect populations more efficiently than warm-season turfgrass monostands.

• Asian Journal of Turfgrass Science
• /
• v.23 no.2
• /
• pp.265-270
• /
• 2009

In October 2009, hunting billbug, Sphenophorus venatus vestitus Chittenden, was first found on zoysiagrass at Yongweon country club in Jinhae. The adult was 6~11mm long and dark brown to black color. The pronotum is coarsely punctate except for a "Y"-shaped area in the center and a parenthesis-like marking on each side. This pattern is characteristic of the species. This billbug feeds on warm-season grasses like zoysiagrass and Burmudagrass. As the hunting billbug is one of the plant quarantine pests in Korea, the National Plant Quarantine Service surveyed additional occurrence for neighboring golf courses and some turfgrass farms, but not found yet.

• Weed & Turfgrass Science
• /
• v.3 no.4
• /
• pp.305-311
• /
• 2014

The cultivation area and use of genetically modified (GM) crops have been increased continuously over the world. Seed distribution and transgenes to environmental ecosystem is one of the most important factors in risk assessment and risk management of GM crop. Safe management for the development and commercialization of GM crops is required according to The Act on Transboundary Movements of Living Modified Organisms,etc (LMO Act) in Korea. This study was conducted to setup the environmental monitoring system of GM zoysiagrass (event JG21 and JG21-MS). The monitoring was performed in 4 GMO confined fields, Sungwhan, Ochang, Jeju University and Jeju Namwon. In the result of monitoring, we could not found any gene flow and distribution of GM zoysiagrass in the 3 fields, but one spill of JG21 was found in the Namwon field in 2012. These results suggest that continuous monitoring is necessary to detect the occurrence of GM zoysiagrass for preventing genetic contamination in natural environment.

• Weed & Turfgrass Science
• /
• v.3 no.4
• /
• pp.370-377
• /
• 2014

Research was initiated to evaluate cool-season grass (CSG) overseeding effects on coverage and species transition in Korean lawngrass (Zoysia japonica Steud.) and to determine CSGs and their seeding rate for a practical overseeding. Treatments were comprised of Kentucky bluegrass (KB, Poa pratensis L.), perennial ryegrass (PR, Lolium perenne L.), tall fescue (TF, Festuca arundinacea Schreb.) and their mixtures. Significant differences were observed in turfgrass coverage and species transition. Since overseeding, the coverage was highest in PR, followed by TF and lowest in KB. The highest coverage in polystand was associated with Mixture IV (TF 50 + PR 50) at a seeding rate of $150gm^{-2}$ which had highest PR and TF, but without KB. Regarding turfgrass transition, zoysiagrass recovery continued to come back up to 80% from late March. But it reduced after early October. Zoysiagrass in monostand was greatest in KB and lowest in TF, but variable in polystand. For the fast and great coverage in winter, it would be the best to apply with PR at $100gm^{-2}$ and equal combination of PR and TF by 1/2 in the mixture at $150gm^{-2}$. For the smooth spring transition to zoysiagrass, however, KB application at $50gm^{-2}$ is recommended.