• Asian Journal of Turfgrass Science
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• v.11 no.1
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• pp.73-85
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• 1997

Although zoysia grass (Zoysia spp.) has a lot of excellent chracteristics as warm-season grass, it have been limited in use due to slow establishment, low seed production, poor shade tolerance and other factors. Breeding trials have been continued from 1900's, much attentions have been paid especially in U.S.A., Korea and Japan recently. In U.S.A., more than 24 varieties had been evaluated at National Turfgrass Evaluation Program(NTEP) from 1991 to 1995 and some were regsistered as commercial. After the 6th International Turfgrass Research Conference at Japan in 1989, Japan Turfgrass In-corporation (JTI) sponsored by private companies and government carried out breeding programs for pest, salt, and shade tolerant and herbicide resistant varieties. JTI also has been trying to im-prove vigor and breed evergreen zoysia Korean breeders collected germplasms since 1960's. After USDA breeders came to Korean penesula in 1982, Korean breeders joined with USDA zoysia breeding project for several years. Many interspecific hybrids and natural selected varieties were breeded that period both in U.S.A and Korea. Breeding objectives were to extend green color period, improve leaf quality and density, and better leaf color at dormant stage. Since 1990's, zoysia grass breeding trials are getting more diverse in many points such as random amplified polymorphic DNA (RAPD) assay for ecotype identification. The objectives of this study are to evaluate germplasms in Korea, and also review the present status and future prospect in zoysia grass breeding in the world.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.3
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• pp.265-269
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• 2021

This study was conducted to provide primary data through analysis of zoysia grass genetic resources to develop grass cultivars with beneficial novel properties. Zoysia grass (Zoysia. spp) is native to Korea, and is mainly propagated through stolons. However, since seed coat treatment technology was developed, the breeding of sexually reproductive grass variants has become possible, necessitating characterization of the floret appearance rate in the secured zoysia grass genetic resource before developing sexually reproductive cultivars. In this experiment, 549 grass lines were examined, revealing that florets appear in only 43 lines (7.81%). Survival rates after transplantation, and stolon generation rates displayed a significant positive correlation (Rho = 0.44). Survival rates after transfer, and rates of stolon production displayed very low correlations with floret appearance (Rho = -0.11 and Rho = -0.06). No significant results were obtained in 43 lines that displayed >20% floret appearance. To breed sexually reproductive grass variants, it is thus necessary to secure more genetic resources, considering the low rate of floret appearance. Finding traits that predict floret appearance at an early stage is also required.

• Weed & Turfgrass Science
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• v.5 no.4
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• pp.256-259
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• 2016

An obligate plant pathogenic fungus Puccinia zoysiae Dietel, the causal agent of rust disease, which is implicated in the damage of zoysiagrass (Zoysia spp.) in Korea. The fungus is one of the important pathogens, which attacks and colonizes susceptible zoysiagrass. Zoysia rust disease was observed in Jangseong, Hoengseong and Hapcheon in 2014 and 2015, Korea. The typical symptoms of the disease appeared first as small white spots on the leaf and stem of zoysiagrass plants, and turn brownish, dark brown spores revealed on the lesions. Uredospores were light brown in color, ellipsoid or spherical in shape and $22.0{\sim}25.0{\times}15.0{\sim}17.5{\mu}m$ in size. On the basis of the morphological characteristics, the fungus was identified as P. zoysiae. Pathogenicity of the fungus was proved by artificial inoculation on Z. japonica. The rust disease firstly appeared approx. early or middle June and then increased middle of October in Korea. In field, Z. matrella ecotypes were more resistant than Z. japonica ecotypes against the pathogen. Disease response against the pathogen was different among ecotypes of each species, respectively.

• Asian Journal of Turfgrass Science
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• v.24 no.2
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• pp.88-96
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• 2010

Zoysiagrass, especially Jungji implicating medium-leaf type zoysiagrass has been widely used in South Korea recently. This study was carried out to classify 36 selected medium-leaf type zoysiagrass accessions compared to 5 basic zoysiagrass species using RAPDs. Morphological characteristics such as leaf width, leaf angle, leaf sheath length, existance of trichomes and stolon color were measured as useful characteristics for identification of species in Zoysia genus. Nineteen RAPD markers were identified using 8 selected random primers. The dissimilarity coefficient of variants ranged from 0 to 0.736. Three zoysiagrass groups were clustered by dissimilarity coefficient analysis. Group 1 consisted of Z. japonica and some US varieties including 'Zenith' and 'Meyer'. Group 2 consisted of Z. sinica, Z. macrostachya and Korean commercial varieties such as 'Anyang', 'Samdeock', and 'Pyeongdong' medium-leaf type grasses. Group 3 was genetically distinct from Group 1 and Group 2, and included Z. matrella and Z. tenuifolia. 'Anyang', 'Samdeock', and 'Pyeongdong' medium-leaf type zoysiagrasses showed very close genetic relationship with Z. sinica and Z. macrostachya.

• Weed & Turfgrass Science
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• v.5 no.2
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• pp.88-94
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• 2016

Vehicular traffic on turf results in loss of green cover due to direct tearing of shoots and indirect long-term soil compaction. Protection of turfgrass crowns from wear could increase the ability of turf to recover from heavy traffic. Plastic turfpavers have been installed in trafficked areas to reduce soil compaction and to protect turfgrass crowns from wear. The objectives of this study were to evaluate traffic performance of turfgrasses (Zoysia matrella and Axonopus compressus) and soil mixture (high, medium and low sand mix) combinations on turf-paver complex. The traffic performance of turf and recovery was evaluated based on percent green cover determined by digital image analysis and spectral reflectance responses by NDVI-meter. Bulk density cores indicated significant increase in soil compaction from medium and low sand mixtures compared to high sand mixture. Higher reduction of percent green cover was observed from A. compressus (30-40%) than Z. matrella (10-20%) across soil mixtures. Both turf species displayed higher wear tolerance when established on higher sand (>50% sand) than low sand mixture. Positive turf recovery was also supported by complementary spectral responses. Establishment of Zoysia matrella turf on turfpaver complex using high sand mixture will result in improved wear tolerance.

• Asian Journal of Turfgrass Science
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• v.25 no.2
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• pp.229-236
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• 2011

This study was carried out to provide recent information on zoysiagrass (Zoysia spp.) sod production in Japan. Total zoysiagrass sod production acreage in Japan was 6,623 ha. The acreage by prefecture was 3,900 ha (58.9%) in Ibalaki, 779 ha (11.8%) in Tostoli, 609 ha (9.2%) in Kagosima, and 550 ha (8.3%) in Sijeumoka, respectively. Sod was harvested by 1.5 cm sod thickness. Mowing height of Goraisiba (Zoysia matrella) and Nosiba (Zoysia japonica) cultivars was cut by 10 mm and 25 mm height, respectively. Japan agricultural cooperative issued a warranty of sod production quality to zoysiagrass consumers. A quality evaluation for sod production was carried out continuously to maintain a reasonable degree of uniformity and hight quality of sod production three times a year. Also, zosiagrass sod production was rotated with Chinese cabbage (Brassica rapa var. glabra Regel) for improving fertility of soil every five to six years. Patented cultivars for promoting bland in Ibaraki prefecture of Japan were 'Tsukuba himae', 'Tsukuba kagayaki', 'Tsukuba Talou' and 'Tsukuba green'.

• The Korean Journal of Mycology
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• v.25 no.4 s.83
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• pp.276-290
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• 1997

Eleven species of Pythium were identified from 125 isolates collected from leaf blight lesions on creeping bentgrass (Agrostis palustris Huds.), Kentucky bluegrass (Poa pratensis L.), and zoysiagrasses (Zoysia japonica Steud., and Z. matrella (L.) Merr.) at 35 golf courses in Korea in $1990{\sim}1996$. The identified species included P. aphanidermatum, P. arrhenomanes, P. catenulatum, P. graminicola, P. myriotylum, P. oligandrum, P. periplocum, P. rostratum, P. torulosum, P. ultimum var. ultimum, and P. vanterpoolii. Mycological characteristics of sporangia, oogonia, antheridia, and oospores observed on the sucrose-asparagine bentgrass leaf culture medium were described for each species. Of the species, P. arrhenomanes, P. catenulatum, P. gmminicola, P. oligandrum, P. periplocum, P. rostratum, P. torulosum and P. vanterpoolii were reported for the first time in Korea. P. myriotylum, P. rostratum, P. torulosum and P. vanterpoolii showed characteristic colony patterns on the potato-carrot agar medium, which can be used as criteria for species identification of Pythium.

• Asian Journal of Turfgrass Science
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• v.13 no.4
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• pp.223-234
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• 1999

Antibiotic activity of selected biocontrol agent Trichoderma harzianum ABGS-95 showed 59% to P. graminicola, 65% to P. aphanidermatum and 57% to Rhizoctonia solani compare to non-treated control. ABGC-95 showed resistant to major agrochemicals such as metalaxyl+mancozeb, etridiazole, propamocarb, toclofos methly, terbuconazole, pencycuron and flutolanil. The biocontrol agent T. harzianum ABGC-95 grew vigorously in low nutrient media and water agar. And sand mixture with wheat bran or mowing debris of zoysia grass also provided good growth of the organism. Application of sand mixture of Trichoderma spp. into aeration cores in golf showed most effective biocontrol of pythium blight. Top dressing application of T. harzianum ABGC-95 reached 83% control efficient while spray application of same biocontrol agent showed only 69% control. The biocontrol agent ABGC-95 successfully suppressed the population density of Pythium spp. in soil. The population density of total Pythium spp. in ABGC-95 treated soil was sustained almost same population at beginning(early May) up to end of August, while the population in untreated control plot was increased 5 times that of beginning and even 10 times in pathogen accumulated soil.

• Journal of Korean Society of Forest Science
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• v.85 no.3
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• pp.347-359
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• 1996

This study was carried out to find the plant succession stage on highway cut-slopes. In order to analyze succession stage, plant survey with belt transect method was carried out in 1989 and 1995 at Joongbu-highway cut-slopes. The results could be summarized as follows ; The mean plant coverage of cut-slope was 78.3%. Plant coverage of Lower part area was higher than that of upper part area. Pioneer herb species on cut-slope were Miscanthus spp., Arundinella spp., Artemisia spp. etc., and pioneer woody species were Rubus crataegifolius, Robinia pseudoacacia, Pueraria thunbergiana, Pinus spp. etc. Also, among the introduced turf grasses, Eragrostis curvula is the pioneer species. Due to short of maintenance works, Zoysia japonica which has been planted by sodding work was found to decrease or diminish gradually. The ratio of pioneer stage plants, domestic and introduced herb species, seems to decrease, while the ratio of woody species which are advanced stage plants seems to increase. Maintenance works are needed to management and monitoring of plant succession on cut-slope, and use of herb and woody species will be effective.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.2
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• pp.88-94
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• 2002

This study was conducted to select suitable turfarasses for use at 2002 world cup soccer fields in Korea. A 1/1000 scale Inchon worldcup soccer dome was constructed for this research. Species and seeding rates of cool-season grasses used inside and outside the dome were Kentuck bleugrass 10g/$m^2$ (KB), Kentucky bleugrass 10g/$m^2$+ perennial ryegrass 10g/$m^2$ mixture (KB+PR) and Kentucky bleugrass 6g/$m^2$+tall fescue 14g/$m^2$+ perennial ryegrass 4g/$m^2$ mixture (KB+TF+PR). Warm-season grasses also used in this study were Zoysia japonica 'Anyangjungzii' (ZA) and Zoysia japonica 'Zenith'(ZZ) which were layed as sod. So, total 5 types of grasses were used inside and outside the dome. The rootzone was constructed by the multi-layer method(United States Golf Association method). The plots were designed by randomized block design. Cool-season grasses(KB, KB+PR, KB+TF+PR) were found to be better performers for visual rating and visual color than the zoysiagrasses(ZA, ZZ). There were no significant differences in turf performance within cool-season grasses, while ZA showed better turf performances than ZZ within zoysiagrasses. The green color was maintained for about 10 months in the col-season grasses(KB, KB+PR, KB+TF+PR) compared to about 5~6 months in the zoysiagrasses. Root length and density data revealed higher values for KB, KB+PR and KB+TF+PR compared to ZA and ZZ. Root performance of 22 was better than ZA within zoysiagrasses which was the opposite result of turf performances. There was also no significant difference between U performance inside and outside the dome. However, the decreasing tendency of turf quality inside the dome at the end of the study showed that more proper maintenance technology was needed inside the d[me. It could be concluded by this study that cool-season grasses(KB, KB+PR, KB+TF+PR) were more suitable turfgrasses than waits-season zoysiagrasses(ZA, ZZ) for use at 2002 world cup soccer fields in Korea.