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

• 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.

• Asian Journal of Turfgrass Science
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• v.4 no.1
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• pp.5-11
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• 1990

Korean Lawn. Zoysia japonica Steud. is the type of a perennial warm-season turfgrass keeping green leaf color for 5 months from May to September in natural condition in Korea. This Studies were carried out to obtain the effects of N-P-K fertilization, regrowth capacity after mowing and chlorophyll contents on prolongation of the green leaf color period in Zoysia japonica Steud turfgrass areas. The results obtained are summarized as follows ; 1.The effects of nitrogen fertilizer application in Zoysia japonica Steud, turfgrass areas were affected on regrowth ability after mowing green color of leaf canopies and chlorophyll contents, respectively(P<.05) 2.A experimental plots which applied 51 g/m$^2$/10 weeks of N$_3$P$_1$K$_1$fertilizer, there were high significant effects on prolongation of the green leaf color period and the plots of phosphorus and potassium had additive effects. 3.Prolongation of the green leaf color period to the last of October was obviously possible by slow degrees in proportation to increment of the fertilizer. However, it is interpreted that more prolongation of the green period is impossible with N-P-K fertilization and irrigation treatments. unless the intermediate turfgrasses between $C_3$ and $C_4$plants must be found and bred.

• The Plant Pathology Journal
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• v.40 no.3
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• pp.272-281
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• 2024

Field surveys were conducted to assess the occurrence and diversity of plant-parasitic nematodes (PPNs) in golf courses and athletic fields across Maryland, USA, during 2022 and 2023. A total of 28 golf courses and ten athletic fields were surveyed, revealing the prevalence and abundance of 13 PPNs taxa in the region. Criconemoides was identified as the most prevalent (94.9%) and Tylenchorhynchus as the most abundant (2.3) across all samples. Central golf courses (west side of the Chesapeake Bay) exhibited a high prevalence of Criconemoides and Tylenchorhynchus, while Eastern Shore golf courses and athletic fields displayed a higher prevalence of Helicotylenchus and Criconemoides. Further, Belonolaimus longicaudatus was reported for the first time from turfgrass in Maryland, raising concerns due to its potential to cause severe damage on both cool- and warm-season turfgrass. Biodiversity analysis indicated that richness (R²) was higher in athletic fields, while diversity (H') and evenness (J') were significantly greater in golf courses. This study provides baseline information for monitoring PPNs distribution in Maryland and also for the development of effective nematode management approaches in turfgrass ecosystems.

• Weed & Turfgrass Science
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• v.6 no.1
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• pp.67-76
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• 2017

The study was initiated to evaluate the effects of overseeding warm-season grass (Zoysia japonica Steud.) with cool-season grasses (CSG) on turfgrass density, uniformity and tiller appearance and to determine turfgrass species and seeding rate applicable for a practical use. 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. Overall turfgrass density and uniformity were much better with the overseeded treatments over the control. In early stage after overseeding, the greater the PR in treatments, the greater the turfgrass density and uniformity. But the higher the KB, the lower the density and uniformity. From the middle-stage evaluation, however, we observed the opposite results as compared with early-stage findings. Accordingly, the KB was highest in turfgrass density and uniformity, while the PR lowest. In regards of mixtures, both turfgrass density and uniformity were better with increased KB and decreased PR in overseeding rates. As for a medium-quality mixtures of Korean lawngrass with CSG, it would be the best choice to apply with KB at $50g\;m^{-2}$ and equal combination of KB, PR and TF by 1/3 in mixing at $75g\;m^{-2}$ in terms of sustainable density and uniformity.

• 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.4
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• pp.427-432
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• 2009

Seashore Paspalum (Paspalum vaginatum Swartz) is a warm season grass and indigenous to tropical and subtropical regions of coastal areas worldwide. The species is used as feed for cattle and horses and has been very successful for golf courses worldwide. One of the most outstanding characteristics of seashore paspalum is its tolerance to saline soils compared to other warm season turfgrasses. The development of new seashore paspalum cultivars with improved traits could be facilitated through the application of biotechnological strategies. The purpose of this study was to product for herbicide resistant seashore paspalum using Arobacterium-mediated transformation and this study is the first report on transformation and herbicideresistant transgenic plants in seashore paspalum. Embryogenic calli were induced from the seeded variety of pseashore paspalum. Embryogenic calli were transformed with Agrobacterium tumefaciens strain EHA105 carrying the binary vector pCAMBIA3301 with two genes encoding gusA and bar. Transformed calli and plants were selected on medium containing 3 mg/l PPT. PCR detected the presence of the gusA and bar gene, indicating both genes are integrated into the genome of seashore paspalum. A chlorophenol red assay was used to confirm that the bar gene was expressed. By application of herbicide BASTA, the herbicide resistance in the transgenic seashore paspalum plants was confirmed.

• Asian Journal of Turfgrass Science
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• v.23 no.2
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• pp.345-352
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• 2009

Zoysiagrass (Zoysia japonica Steud) is a warm season turfgrass species widely used for sports field and golf courses. Many cultivars are propagated through vegetative methods. This study was conducted to develop an optimum culture medium and culture conditions for embryogenic callus induction and plant regeneration, and to establish a cell suspension culture system for use in zoysiagrass breeding and propagation. The results indicated that adding $Cu^{++}$ at 2.5 mg $L^{-1}$ to the induction medium was optimum for callus induction. Increasing the numbers of sub-culture cycles improved the quality of calli. The optimum dosage for cell suspension culture ranged from 2.5 to 10 mL. The embryogenic callus suspension used in this study had a plant regeneration rate of 58%.

• Journal of Plant Biotechnology
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• v.37 no.4
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• pp.400-407
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• 2010

Zoysiagrass (Zoysia japonica Steud.), also called Korean or Japanese lawngrass, is the most popular warm-season turfgrass in Korea and is widely used for home lawns, parks, roadsides, golf courses and athletic fields. Its use is rapidly expanding in Korea and the other countries, due to its excellent characteristics which include tolerance to heat, drought and salinity. As the utilization area of this turfgrass increases, there is an increase in the demand for improved cultivars with disease and insect tolerance or with herbicide-tolerance or with extended greening periods. Conventional breeding methods have been used to improve the traits described above with limited success. However, with the advances in biotechnology, genetic transformation can be utilized for turfgrass improvement. In this paper, we review recent progress in biotechnological improvement of zoysiagrass and discuss future molecular breeding of this species.

• Asian Journal of Turfgrass Science
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• v.23 no.2
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• pp.287-294
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• 2009

This study conducted to evaluate the growth characteristics of creeping bentgrass in summer after application of the plant growth regulator, Trinecapac-ethyl, and these data may provide basic information to golf course turf maintenance. The results showed that the shoot density of creeping bentgrass was increased an average density of 1.7 $ea/cm^2$ with the trinexapac-ethyl application, especially about 2 $ea/cm^2$ during the growth retarded period of June and July. The root length increased also in June and August. The visual quality was improved significantly with trinexapac-ethyl treatment all the experimental periods, moreover, the effect was significant by reducing a summer decline stress of creeping bentgrass during the warm and humid period of summer. The green speed was significantly improved by this growth regulator treatment and those effect was prominent during stressed season of late June to mid July. Overall of the result, we found that shoot density, visual quality and green speed of bentgrass green were improved by trinexapac-ethyl treated from early growing season of spring and these effects were continued during summer. It should be very beneficial to manage the bentgrass green in stressed season. In future, the possibility and efficiency of mixture with fungicides and/or fertilizers might be needed. The spring green-up test with trinexapac-ethyl will be followed in next spring.