• Asian Journal of Turfgrass Science
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• v.23 no.1
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• pp.9-22
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• 2009

Due to increasing concerns over issues with both water quantity and quality for turfgrass use, research was conducted to determine the response of five warm-season turfgrasses to deficit irrigation and to gain a better understanding of relative drought tolerance. St. Augustinegrass(Stenotaphrum secundatum [Walt.] Kuntze.) cultivars 'Floratam' and 'Palmetto', 'SeaIsle 1' seashore Paspalum(Paspalum vaginatumSwartz.), 'Empire' zoysiagrass(Zoysia japonica Steud.), and 'Pensacola' bahiagrass(Paspalum notatum Flugge) were established in lysimeters in the University of Florida Envirotron greenhouse facility in Gainesville. Irrigation was applied at100%, 80%, 60%, or 40% of evapotranspiration(ET). Evaluations included: a) shoot quality, leaf rolling, leaf firing; b) leaf relative water content(RWC), soil moisture content, chlorophyll content index(CCI), canopy photosynthesis(PS); c) multispectral reflectance(MSR); d) root distribution; and e) water use efficiency. Grasses irrigated at 100% and 80% of ET had no differences in visual quality, leaf rolling, leaf firing, RWC, CCI, and PS. Grasses irrigated at 60% of ET had higher values in physiological aspects than grasses irrigated at 40% of ET. 'Sealsle 1' and 'Palmetto' had a deeper root system than 'Empire' and 'Pensacola', while 'Floratam' had the least amount of root mass. Photosynthesis was positively correlated with visual assessments such as turf quality, leaf rolling, leaf firing, and sensor-based measurements such as CCI, soil moisture, and MSR. Reducing the amount of applied water by 20% did not reduce turfgrass quality and maintained acceptable physiological functioning.

• Asian Journal of Turfgrass Science
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• v.3 no.1
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• pp.39-52
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• 1989

Native Kerean lawngrass (Zeysia japonica steud.) and Manilagrass ( Zeysia matrella Merr.) are frequently used as sport turf and lawn in Kerea and ether Asian countries because of its excellent summer qualities and superior winter-hardiness compared to ether warm-season turfgrass . The objective of this study was to investigate the effect of the plant growth retardants ( PGR ) en the inhibition (d the growth of the two Kerean native turfgrasses. Kerean lawngrass and Manilagrass were treated with [2 RS , 3 RS] -1- [4- chlorophenyl ] -4, 4-dimethyl -2- [1 H -1, 2, 4- tiazol -1- y] pentan -3- ol ( PP -333) at 93 and 930 gha -j ; 5-[4- chlorphenyl ]-3, 4, 5, 9, 10- peiitaaza - tetracyclo [5, 4, 1, 0 2 6 . o ~'~I -3, 9- diene ( BAS -106) at 16 and 160 gha ; [ E I-] - cyclohexyl -4, 4- dimethyl -2- [1, 2, 4- triazol -1- yl ]-1-pentene - 3- ol ( NTN -821) at 56 and 560 gha ', and 4- chloro -2- [$\alpha$- hydrozybenzy I isonicotin anilide ( CGR -811) at 92 gha in pot study . All PGR treatments were effective in reducing the plant height, with the exception of BAS -106 at 16 gha for Korean lawngrass ; however , all increased quality to some degree , with the exception of PP -333 at 93 gha . The low PGR rates significantly increased Korean lawngrass height during late jtily aitd mid-August . On the other hand , BAS -106 significantly increased Manilagrass height {rom 24 Septeml)er onwards . All PGR treatments haol higher turfgrass quality than untreatments , and also the high rates of PGIt treatments were more effective in increasing quality than the low rates observed on 8 October . Meanwhile , Manilagrass quality was increased to some extent than Korean lawegrass . PP - 333 was significantly effective in reducing clipping yield and the same results were found with the application of NTN -821 at 560 gha -l for both Korean lawngrass and Manilagrass , BAS -106 at 160 gha for Korean lawegrass , and CGR -811 at 92 gha for Manilagrass . The high PGR rates had higher turfgrass shoot weight observed on 8 October than the low rates , and there were little increases obtained with the low rates of PP -333 for Korean lawngrass and BAS - 1 06 for Manilagrass . Effeets on stolon growth varied between growth retardants , and between retardant treatments ; the high rates of PGR as well as the low rate of NTN -821 elongated stolon of Korean lawngrass and manoilagrass . However , PP -333 at 93 gha and BAS -106 at 16 gha - shortened stolons of Korean lawugrass , resulting in inhibition or little difference of stolon dry weight . NTN -821 at 560 gha and CGR -811 had no positive effect on the stolon length of Manilagrass . 101) -333 and the low rate of BAS -106 and NTN -821 decreased root weight of Korean lawng - rass All PGR rates had negative effect on the root weight of Manilagrass with the exception of BAS -106 CR -811 and the high rate of NTN -821 which made no difference in root weight between retarolant treatments and the control .

• Asian Journal of Turfgrass Science
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• v.25 no.2
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• pp.217-222
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• 2011

Professional turfgrass applicators have reduced or eliminated phosphorus from their fertilization programs based on the assumption that soil phosphorus levels are supplying adequate amounts of phosphorus to the turfgrass. The previous researchers found that there were no P effects for turfgrass growth especially for mature turf. No effects may result from high P level in heavy thatch layer. The research was conducted for one year to investigate the effects of phosphorus fertilization programs on turfgrass performance, and monitor soil and plant tissue nutrient levels to determine the impact of the programs on a newly seeded Kentucky bluegrass. The nitrogen treatments were 20, 30 and $40g\;m^{-2}\;yr^{-1}$. The low, medium, and high nitrogen treatments were applied over 2, 4 and 6 applications, respectively. Nitrogen was applied using a formulation containing 30% of slow and 70% of fast release nitrogen sources that are representative of typical home lawn fertilizers. The phosphorus treatments were 0, 10 and $20g\;m^{-2}\;yr^{-1}$. Phosphorus was applied according to the application schedule for the nitrogen treatments. Kentucky bluegrass was seeded in May, 2010. The thickness of thatch layer was less than 1 cm and the first treatment was applied to Kentucky bluegrass in April, 2011. The low N rate treatment had acceptable color and quality ratings without high clipping yields. The high N rate treatment consistently had the highest color and quality ratings but also had very high clipping yields in comparison to the low and medium N rate treatments. Although there are significant differences in tissue P, Overall, there was no effect of phosphorus on color, quality, or clipping weights.

• Weed & Turfgrass Science
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• v.5 no.1
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• pp.42-50
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• 2016

Superintendents have been used microbial fertilizers to improve turfgrass growth and quality and to decrease turfgrass diseases in golf course. This study was conducted to investigate the effects of compound fertilizer containing microbe (MF) on the growth and quality of creeping bentgrass with turf color index (TCI), chlorophyll index (ChI), root length, turfgrass density, clipping yield and nutrient content. Treatments were designed as follows; non-fertilizer (NF), compound fertilizer (21-17-17; CF) as control, compound fertilizer (14-6-17) containing microbe. In pot experiment, TCI and ChI of creeping bentgrass in MF plot were similar to those in CF. But clipping dry weight of MF plot increased by 39.1% compared to that of CF plot. At field experiment applied with MF treatment, TCI, ChI, root length, and nutrient content and uptake of creeping bentgrass were similar to those with CF treatment, but turfgrass density with MF higher about 7.9-15.8% than with CF. These results indicated that the application of MF improved growth and quality of creeping bentgrass by enhancing clipping yield and shoot number.

• Journal of Korean Society of Forest Science
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• v.68 no.1
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• pp.18-31
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• 1985

Users' satisfaction and behavior at five mini parks in the central area of Seoul City were investigated under the encironmental design evaluation framework. The major findings are as follows; 1) The major user group is a student group with the ages ranging from 15 to 24. 2) Half of the users spend 20 to 60 minutes in these parks. 3) According to the multiple regression analysis, the variables related to the satisfaction in daytime are noise level, sunshine, plants, crowding, and surface slope, where those in nighttime are quality of surrounding buildings, turf area, lighting, shade, and sculpture or fountain. 4) According to the free response, the basic needs inmini parks are shade for rest and such amenity facilities as bench, trash basket, and drinking fountain. In addition to these basic needs, users prefer such visually pleasing objects as sculpture and fountain.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.1
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• pp.13-23
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• 2016

This study was conducted to investigate the growth characteristics of warm-season turfgrasses and to find out suitable turfgrass species on Saemangeum reclaimed land. Twenty native zoysiagrass(Zoysia sinica, Z. matrella, Z. japonica, Medium-leaf type zoysiagrass(hybrid zoysiagrass)) and bermudagrass(Cynodon dactylon) collected from Korea were used in this study. Total stolon length and the number of stolon per square meter, relative growth rate of shoot and stolon, and coverage rate were analyzed for 2 year. C. dactylon showed not only the most growth response with high relative growth rate of shoot and stolon, which were 19.9% and 66.3%, but also resulted in higher level of turf visual quality compared to others. Whereas Z. japonica showed the least growth response with low relative growth rate of shoot and stolon, which were 2.4% and 0.7%. Although all warm-season turfgrasses took root and grew up well, there were different growth rates between the interspecies. Z. sinica 'Z2034', Z. matrella 'Z4091', Z. japonica 'Z1064', Medium-leaf type zoysiagrass 'ZN6019' and C. dactylon 'BN7014' were the greatest growth rate of shoot and stolon. These results will be useful for selecting salt tolerant breeding lines and also used to develop a turfgrass cultivar with strong salinity tolerance through continuous monitoring.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.4
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• pp.259-264
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• 2001

To investigate the physiological responses to naturally occurring winter freezing stress in creeping bentgrass, changes in carbohydrates were monitored during winter period. Turf quality and leaf growth was nearly parallel with temperature fluctuation. The concentration of glucose, fructose and sucrose in both shoot and root gradually increased from November to January, and then sharply decreased until April. Sucrose was the largest pool of soluble sugars. Fructan also slightly accumulated in both shoot and roots from November to February. Fructan hydrolysis in both organs was found to be much active between February to April. Shoot contained largely higher carbohydrate content in all compounds examined than roots did. Fructan was found to be a main carbohydrate storage form, showing the highest concentration (176.7 and 126.7 mg g-' DW for shoot and root in February). The depolymerization of fructan from February coincided with the high declines in mono- and disaccharide. These results suggest that the accumulation of non-structural carbohydrate until January could be associated with freezing tolerance, and the active decrease from February with shoot regrowth.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.3
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• pp.1-12
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• 2000

식물생장조절제(Plant Growth Regulators, PGRs)를 이용한 예초관리 방법이 들잔디 엽색 및 품 질에 미치는 영향을 규명함으로 잔디 적응력 관점에서 적합한 PGR 종류 및 살포수준을 파 악하고자 본 연구를 시작하였다. 실험은 들잔디 생육이 왕성한 시기인 6월(실험 I)과 7월(실험 II) 2회에 걸쳐 각각 다른 장소에서 실시하였다. 공시약제 처리구는 Type I PGR인 amidochlor 3 수준 및 mefluidide 3 수준 과 Type II PGR인 trinexapacethyl 4 수준, 그리고 무처리구를 포함하여 전체 11 처리구였 고, 실험구 배 치는 난괴법 4 반복으로 하였다. 공시한 3종류 PGR 모두 잔디엽색 및 품질에 통계적으로 유의한 차이 가 있었지만, PGR 종류.살포수준 및 생육 상태에 따라 처리효과는 다르게 나타났다. 잔디 엽색 및 품질 은 PGR 살포후 경과기간에 따라 점진적으로 억제되는 경향이었다. 처리 1주후 잔디품질은 대조구에 비 해 큰 차이가 없었지만, 2주에서 4주까지는 PGR 종류 및 살포수준에 따라 유의하게 감소하 여 0.08 ml/ $m^2$ 이상의 trinexapac-ethyl 처리구 및 1.20 ml/$m^2$ 이상의 mefluidide 처리구에서는 가장 크 게 나타났다. 처리 4주부터 대부분 처리구에서 잔디품질이 적정수준 이상으로 회복되기 시작하였다. 본 실험을 통해 잔디관리 수준에서 저관리 잔디지역은 0.08 ml/$m^2$ 수준의 trinexapac-ethyl 처리구가 장기간 생장억제 관점에서 실용성과 경제성 측면에서 들잔디 관리에 효율적인 것으로 판단되었고, 고관리 잔 디지역은 0.04~0.08ml/$m^2$ 수준의 trinexapac-ethyl 처리구 및 0.60~1.20 ml/$m^2$ 수준의 amidochlor 처 리구가 적합 한 것으로 판단되었지만, 계절에 따라 PGR 효과정도가 다르게 나타났다. 따라서, 잔디 관리 시 잔디의 생육상태, 예초 절감 기간, 잔디품질의 기대수준 및 적용할 수 있는 관리수준에 따라 적합한 PGR 종류 선정과 함께 살포시기 및 살포량을 효율적으로 결정하는 것이 필요한 것으로 사료되었다.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.2
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• pp.21-32
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• 2011

The effects of high polymer on the seedling survival were investigated in three major turfgrasses. Twelve treatments were used in the study with different rates of sand, soil organic amendment (SOA), and water-swelling polymer (WSP). Turfgrass seedling survival rate was evaluated in creeping bentgrass (CB), Kentucky bluegrass (KB), and zoysiagrass (Zoy) grown under greenhouse conditions. Significant differences were observed among the treatments. Seedling survival rates were variable in CB, KB, and Zoy according to mixing rates of SOA and WSP, being maximum 20.2% in differences. At 6 weeks after seeding, the survival rates ranged from 0.6 to 61.9% in CB, 4.2 to 75.3% in KB and 1.7 to 82.1% in Zoy. A pattern of seedling emergence varied with time among treatments influenced by WSP rates. A proper mixing rate of WSP is considered to be 5% for CB and 5 to 10% for KB and Zoy. In general, overall effect of WSP on seedling survival was clearly observed in the mixtures of sand 80% and SOA 20% in CB. The best result, however, was found from the mixture of sand 85% and SOA 15% in both KB and Zoy. When mixing sand with WSP, a proper rate of SOA is considered to be 20% for CB and 15 to 20% for KB, while 10 to 15% for Zoy. A further research is needed to investigate the effects of WSP on the turf quality in mixtures of sand, SOA, and WSP before a field application.

• Asian Journal of Turfgrass Science
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• v.20 no.2
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• pp.213-221
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• 2006

This study was designed to determine what sensor-based technologies might reliably and accurately predict irrigation scheduling needs of warm-season turfgrass. 'Floratam' St. Augustinegrass[Stenotaphrum secundatum(Walt.) Kuntze] and 'Sea Isle I' seashore paspalum(Paspalum vaginatum Swartz) were established in tubs in the Envirotron Turfgrass Research Laboratory in Gainesville, FL in the spring of 2002. Each grass was subjected to repeated dry-down cycles where irrigation was withheld. Sensor-based data were collected and these evaluations were used to determine if irrigation scheduling could be determined based on plant response during dry-down. Results indicated that reflectance indices($P{\le}0.001$) and soil moisture($P{\le}0.0001$) throughout the dry-down cycle can predict the need for irrigation scheduling as turf quality declined below acceptable levels.