• Asian Journal of Turfgrass Science
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• v.6 no.2
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• pp.99-111
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• 1992

Yellow patch as leaf blight caused by binucleate Rhizoctonia occured in bentgrass (Agrostis Palustris Huds), zoysiagrass (Zoysia japonica Steud) and Kentucky bluegrass (Poa pratensis L.) from several golf couses in Korea. Binucleate Rhizoctonia was isolated from the infected lesions and was identified Rhizoctonia cerealis. Rhizoctonia cerealis infected crown, stem and leaf tissue, and the symptom was light yellow circular patch upto 1 m in diameter on bentgrass golf green. Individual infected leaf near the margin of patch developed first red and finally turn brown. As zoysiagrass lawn, the symptom was 30~40cm circular patch that occured zoysiagrass shooting time as spring, and there could not sheeted in severe lesion. In case of sheeted, zoysiagrass was first irregular leaf sopt and finally dead. Hypha diameter of Rhizoctonia cerealis was $2.5~6.3\mu\textrm{m}$(average $3.8\mu\textrm{m}$) and colar was white to buff. Monilioid cell size was $5.8~12.5$\times$13.8~37.5\mu\textrm{m}$. Sclerotia size was 0.2~2.0mm and color was white to brown. Optium temperature for the hypha growth was $23^{\circ}C$. There was a little difference in pathogenicity among the isolates.

• Weed & Turfgrass Science
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• v.3 no.3
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• pp.246-252
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• 2014

This study was conducted to evaluate the effects of two amino acid fertilizers on the growth of creeping bentgrass and N uptake. Fertilizer treatments were designed as follows; non-fertilizer (NF), control (CF), recommended amount (ALF), double amount (2ALF) of amino acid liquid fertilizer (AaLF), recommended amount (ASLF) and double amount (2ASLF) of amino acid liquid fertilizer contained with saponin (AaSLF). Turf quality of treatments of AaLF and AaSLF such as turf color index, chlorophyll index and root length was similar to the treatment of CF. Dry weight and content, uptake and availability of N were investigated highest in the 2ALF and 2ASLF. These results suggested that foliar application of AaLF and AaSLF was enhanced turf quality and growth of creeping bentgrass by stimulating uptake and availability of N.

• Asian Journal of Turfgrass Science
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• v.22 no.1
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• pp.13-24
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• 2008

This study was carried out to provide basic information for the breeding of zoysiagrass synthetic varieties. For estimation of flowering periods, genetic characteristics, and cross-pollination rate, 5 combinations of zoysiagrass breeding lines were compared. Days to stigma emergence and anther exertion were observed in the field to calculate overlapping dates for cross-fertilization. Harvested seed from cross breeding combinations were planted to compare genetic characteristics using morphological traits of progenies. These data were used for determination of 7 phenotypic inheritance types with 8 morphological traits. Cross-pollination rates in 3 combinations of zoysiagrasses were estimated by using lower part color of grass shoots. Cross-pollination rates of zoysiagrass ranged from 11.3$\sim$48.9%, which indicated that zoysiagrass is an allogamous plant. When zoysiagrass breeding lines are properly combined, they may result in valuable synthetic cultivars.

• Weed & Turfgrass Science
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• v.7 no.3
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• pp.231-238
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• 2018

This study was carried out to develope new zoysiagrass cultivars 'JangsungChorok' (Application No. :2013-3) and 'JangsungSaetbyeol' (Application No. :2013-4). One hundred and one genetic resources were collected at Jangsung Gun area from 2010 to 2011. Among the collected lines, CY6097 (JangsungChorok) and CY6069 (JangsungSaetbyeol) showed superior performance in spring green up and growth rate. 'JangsungChorok' showed genetically light green leaf color, with medium leaf width (4.4 mm), height from ground to first leaf blade of 3.2 cm and average plant height of 18 cm. Fast recovery rate and early spring green up rate will make this cultivar (JangsungChorok) for efficient sod producer. 'JangsungSaetbyeol' showed genetically dark green leaf color, with fine to medium leaf width of 3.5 mm, height from ground to first leaf blade of 4.3 cm and average plant height of 22.6 cm. Fast recovery rate and early spring green up rate with relatively narrow leaf will make this cultivar (JangsungSaetbyeol) for high sod quality.

• Asian Journal of Turfgrass Science
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• v.23 no.1
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• pp.123-132
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• 2009

This study was designed to investigate the effect of the late fall fertilization applied with methyl urea(MU), compound chemical fertilizer(CF), humate(HM), and organic compost fertilizer(NS) on spring greenup of creeping bentgrass at following year. The plots were treated with various snow cover periods before transforming to ski slopes from golf holes during 2007 fall to 2008 spring. The highest visual quality and greenup rate were shown on MU or HM applications at 10 days before snow cover treatment. The CF treatment which had a highest phosphorus rate was most effective with a 13 cm of root length at the reconversion date to golf hole from ski slope of the following spring. However, the application of CF followed by immediate snow cover showed the worst results on visual quality and green color caused by a leaf burning damage from the residual effect of CF. At least 10 days were required to avoid phytotoxicant from undissolved granular of CF before snow cover practise. The application of NS showed the highest result on leaf dry weight at no snow cover plot in next spring, but not on green color and visual quality. Therefore, the proper interval period of snow cover after late fall fertilization should be an important management skill on the spring greenup of creeping bentgrass on following year transforming from ski slope to golf hole.

• Asian Journal of Turfgrass Science
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• v.22 no.2
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• pp.185-196
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• 2008

This Study was conducted to evaluate the effect of liquid fertilizer containing medium of on growth of shoot and root in creeping bentgrass (Agrostis palustris Huds. cv. Pennlixs). According to application method of liquid fertilizer, the experiment plot was designed as follows; NF : non-fertilizer; CF : compound fertilizer(21-17-17) only; T500, T300, T100 : compound fertilizer +liquid fertilizer solution diluted 500, 300, 100 folds, respective; L500 : only liquid fertilizer solution which contained the medium of Lactobacillus confusa and Pichia anomala diluted 500 folds. The every treatments was arranged by a completely randomized complete block designs with three replications. The order of turf qualities like leaf color index and chlorophyll content in treatments showed T500 T300 T100 $\geq$ CF > NF. In treatment applied with compound fertilizer, the dry weight of shoot increased by about 13% in T500, T300 and T100 than CF, and that of root about 25% in just T300. Dry weight of shoot and root increased by 88% and 44% in L500 than NF, respectively. As compared with CF, T/R ratio in T500, T300 and T100 increased by 20%, 11% and 21%, respectively and root length 7%, 8% and 3%. In comparison with NF, T/R ratio and root length in L500 increased by 39% and 74%. These results suggested that the application of liquid fertilizer containing medium of Lactobacillus confusa and Pichia anomala induced the development of turf quality and growth by promoting root growth in creeping bentgrass.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.2
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• pp.61-70
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• 2000

The purpose of this study is to identify the proper species of turf and the ground structure for the turf sports grounds. Analysis items are particle distribution of sand and gravel, saturated hydraulic conductivity, soil hardness, and turf growth. Results of this study are as follows. 1)The particle distribution of sand used in the multi-layer rootzone is within the upper limit of the standard level. The diameter of mid-size grain({TEX}$D_{50}${/TEX})was 0.62mm and the value of uniformity ({TEX}$D_{90}${/TEX}/{TEX}$D_{10}${/TEX}) was 3.93. The particle size distribution of sand used in the single-layer rootzone was beyond the standard level as {TEX}$D_{50}${/TEX})=0.86 and {TEX}$D_{90}${/TEX}/{TEX}$D_{10}${/TEX}=8.86. 2) Saturated hydraulic conductivity of the sand was higher in the multi-layer rootzone than in the single-layer rootzone while bulk density was vice versa. 3) Surface hardness was high on Kentucky bluegrass+perennial ryegrass compared to zoysiagrass probably caused by root density. 4) Visual covering and visual rating were highly evaluated on zoysiagrass within summer while better evaluated on Kentucky bluegrass+perennial ryegrass throughout fall to spring. 5) Visual color was better evaluated on Kentucky bluegrass+perennial ryegrass than on zoysiagrass throughout the year. These studies are demanded urgently according to increase in interest in the ground and turf species of the turf sports ground because of World Cup 2002.

• Asian Journal of Turfgrass Science
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• v.18 no.3
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• pp.149-163
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• 2004

Physical and chemical properties of root zone mixes and methods of green construction are important considerations for improving turf grass quality for putting greens. This study compared Penncross creeping bentgrass (Agrostis palustris Huds.) performance as affected by three root zone construction systems with three amendments (sand, peat, and zeolite). The objective of this study was to determine if an amended California construction system would improve green performance during establishment (1998-1999) and maturation (2000-2001). Three treatments were tested: California ($100\%$ sand), USGA($90\%$ sand and $10\%$ peat, v/v), and California-Z ($85\%$ sand and $15\%$ zeolite, v/v). Treatments were arranged in a randomized complete block with four replicates. Physical and chemical properties of the root zone and bentgrass performance were compared for the treatments. The California-Z treatment had the highest saturated hydraulic conductivity, field infiltration rate and the lowest bulk density. It also had the highest cation exchange capacity and plant available nutrient concentrations among the three treatments. The California-Z treatment produced bentgrass quality and color during green establishment and maturation that were equal to or higher than the California treatment, and consistently higher than the USGA treatment. The addition of an inorganic amendment to the California system improved physical and chemical properties of the root zone and improved quality and color of bentgrass during green establishment. During green maturation, creeping bentgrass in the California-Z treatment was equal (6 of 15 sampling dates) or $20\%$ higher (9 of 15 dates) in quality compared to the California system.

• Weed & Turfgrass Science
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• v.2 no.1
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• pp.15-22
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• 2013

The phenotypic traits of herbicide-tolerant transgenic rice were compared with those of wild type (Dongjin) as well as two accessions (Hwaseong-aengmi 1 and Gwangyang-aengmi 12) of weedy rice. This study was conducted to investigate whether unintentional alterations in phenotypic characteristics occurred in the transgenic rice and whether the altered traits were similar to those in the two weedy rices. All qualitative traits studied were similar in the transgenic or wild-type rice. On the other hand, awn presence, flag leaf attitude and grain color differed considerably between herbicide-tolerant transgenic rice and weedy rice. As for quantitative traits, plant height, the number of tillers per plant and shoot dry weight were significantly greater for weedy rice than transgenic or wild-type rice. Grain weight per plant and 1000-grain weight of transgenic (or wild-type) rice were significantly greater than those of weedy rice. Transgenic rice shattered less than the other rices. Amylose and protein contents in embryos of transgenic rice were significantly different from those of weedy rice. The potential for weediness of the transgenic rice may be assessed using phenotype comparison between transgenic and weedy rice as shown in this study.

• Weed & Turfgrass Science
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• v.6 no.4
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• pp.306-312
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• 2017

This study was carried out to develop new hybrid zoysiagrass cultivar 'Seah' (The application no. for cultivar protection : 2014-22). Native zoysiagrasses were collected from south-west seaside of Korea from 2010 to 2011. Artificial crossing was conducted to develop F1 hybrid between Z2011 (Z. sinica) and NM1 (Z. matrella) at plastic house in 2011. Among the progenies, 'Seah' showed fine leaf texture and high shoot density from the space planting plots at field. 'Seah' showed genetically light green color, with fine leaf with 1.8mm and height to the lowest leaf blade was 1.94 cm. Ground coverage rate was slower than medium leaf zoysiagrass (Jung-gi), but plant height of 7.1 cm was the lowest among the compared zoysiagrasses and height to lowest leaf of 1.94 cm was lower than most zoysiagrass, which may allow low mowing height.