• Korean Journal of Weed Science
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• v.32 no.3
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• pp.222-229
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• 2012

In this study, we attempted to control invaded hetero-species turfgrass in golf courses with herbicides. Asulam sodium SP and trifloxysulfuron-sodium WG (to control creeping bentgrass in zoysiagrass), trifloxysulfuron-sodium WG (to control kentucky bluegrass in zoysiagrass), and mesotrione SC (to control creeping bentgrass in kentucky bluegrass) were selected as efficient herbicides. To creeping bentgrass, asulam sodium SP and trifloxysulfuron-sodium WG until 70 days after application (DAA), mesotrione SC until 230 DAA and to kentucky bluegrass trifloxysulfuron-sodium WG until 110 DAA; the applications showed 90% herbicidal effect. At 4 X recommended application dose, asulam sodium SP, trifloxysulfuronsodium WG (to zoysiagrass) and mesotrione (to kentucky bluegrass) showed insignificant harmful effect. With recommended dose, asulam sodium SP showed 80% control effect of creeping bentgrass in zoysiagrass until 40 DAA and trifloxysulfuron-sodium WG demonstrated 85% control efficiency until 30 DAA. Trifloxysulfuron-sodium WG controlled 85% of kentucky bluegrass in zoysiagrass until 40 DAA. Mesotrione SC with recommended dose showed 95% control efficiency to creeping bentgrass in kentucky bluegrass.

• 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.2
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• pp.134-138
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• 2001

This experiment evaluates wintering ability to maintain green color of lawn grasses during winter and investigates the effects of top dressing of fertilizer on improving green color during regrowth. Kentucky blue-grass could maintain green color and leaf chlorophyll content better than tall fescue and creeping bentgrass in winter. All three grasses in this experiment have shown the excellent wintering ability. In enhancing the recovery of green color at the early stage of regrowth, the mulching effect with rice straw was highly significant for creeping bentgrass. Green color recovery in grasses during its regrowth was better at the top dressing plots than at the plots without top dressing, but when fertilizer application levels were increased, green color in lawn grass did not significantly change. Although green color in tall fescue, Kentucky bluegrass, and Korean lawngrass could be maintained during summer, the green color of creeping bentgrass is reduced significantly with high temperature. Top dressing after winter and mowing improved leaf chlorophyll content and green color in tail fescue and Kentucky bluegrass significantly. However, Korean lawngrass did not respond significantly with increased levels of fertilizer.

• Weed & Turfgrass Science
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• v.6 no.4
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• pp.313-321
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• 2017

Wetting agent is designed to reduce the surface tension of the liquid and spread more easily across or penetrate into the soil against water repellency. The effect of wetting agent to seed germination is not clear. Using germination enhancer is one of the methods to increase the germination speed of turfgrass seeds and to shorten establishment period. The objective of the study was to evaluate germination enhancer and wetting agent for quick establishment of various Kentucky bluegrass cultivars. The germination enhancer was used at two levels of 0.3 and $0.6ml\;kg^{-1}$ as low and high, respectively. Two levels of wetting agent were of 0.46, and $0.92ml\;m^{-2}$ as low and high, respectively. Germination enhancer has no synergistic effect with wetting agent. When quick establishment is required, selection of cultivar would be more effective instead of using germination enhancer and wetting agent. Among Kentucky bluegrass cultivars, 'Award' had the greatest turfgrass coverage for establishment and the greatest turfgrass color and quality based on the result of the study. When quick establishment is required, selection of cultivar would be more effective instead of using germination enhancer and wetting agent.

• Asian Journal of Turfgrass Science
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• v.26 no.2
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• pp.102-109
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• 2012

Commercial formulation of fungicides was studied in the golf course for evaluation against Typhula incarnata causal agents of gray snow mold. Efficacies of fungicides application, fungicide mixture, fungicides applied method (irrigation and spray) and fungicides applied time (early fall and late fall) were evaluated for their influence on the chemical control of gray snow mold of turfgrass during the winter season in Yongpyeong golf course, Korea. Unsprayed control has significantly more disease severity than three fungicides (azoxystrobin, propiconazole, and tebuconazole) were applied to field plots. Effect of three fungicides was over 80% with control value for controlling gray snow mold on Kentucky bluegrass and creeping bentgrass species. Effect of fungicide mixture with different family groups had an over 93% control value of gray snow mold on Kentucky bluegrass species. It was not significantly difference in fungicidal effect according to applied method (irrigation and spray) with azoxystrobin on Kentucky bluegrass and creeping bentrasss species. Effect of fungicides applied time was a significantly difference on disease control by tebconazole early fall spray.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.3
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• pp.344-350
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• 2011

Kura clover (Trifolium ambiguum M. Bieb.) is a potentially useful perennial legume because of its excellent nutritive value and persistence under environmental extremes. However, information about forage quality of kura clover - grass mixtures adapted to the North-Central USA is limited. Objectives of this research were to determine forage nutritional value of kura clover-grass mixtures under different harvest frequency and cutting height regimes. 'Rhizo' kura clover was grown alone and in binary mixtures with 'Park' Kentucky bluegrass (Poa pratensis L.), 'Comet' orchardgrass (Dactylis glomerata L.), and 'Badger' smooth bromegrass (Bromus inermis Leyss.) at the Arlington Agricultural Research Station located near Madison, WI. Three harvest frequencies ($3{\times}$, $4{\times}$, or $5{\times}$ annually) and two cutting heights (4- or 10-cm) were imposed on each binary mixture and on kura clover grown alone. Higher nutritive value was observed in the binary mixtures with more frequent harvest and lower cutting height. Averaged over 3 years and all harvest frequency and cutting height treatments, the nutritive value of the Kentucky bluegrass and smooth bromegrass mixtures was superior to that of the orchardgrass mixture ($410\;g\;kg^{-1}$ NDF and $194\;g\;kg^{-1}$ CP in the Kentucky bluegrass mixture; $405\;g\;kg^{-1}$ NDF and $188\;g\;kg^{-1}$ CP in the smooth bromegrass mixture; $435\;g\;kg^{-1}$ NDF and $175\;g\;kg^{-1}$ CP in the orchardgrass mixture). All of the mixtures and harvest management systems evaluated in this study produced forage with quality equivalent to "grade one" alfalfa hay and suitable for highproducing livestock, even though the highest quality was observed in the Kentucky bluegrass mixture with $5{\times}$ harvesting at the shorter cutting height.

• Asian Journal of Turfgrass Science
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• v.22 no.2
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• pp.141-148
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• 2008

This study was conducted to investigate nutrient content at shoot and root(contained runner in zoysiagrass) in creeping bentgrass, kentucky bluegrass and zoysiagrass before turfgrass dormancy. The shoot ratio of dry weight in creeping bentgrass, kentucky bluegrass and zoysiagrass was 12%, 27% and 25% and root ratio was 88%, 73% and 75%, respectively. The orders of nutrients contained in turf-grass were N>K>Ca>P>Mg>Na in plant tissues. The proportion of nutrients in tissue of creeping bentgrass, kentucky bluegrass and zoysiagrass was 17%, 28% and 34% in shoot and 83%, 72% and 66% in root, respectively. These results showed that nutrients in turf-grass tissue was contained more than 70% in root before grasses dormancy. In turf grass management, all grasses were required to fertilize sufficiently N, $K_2O$, CaO and $P_2O_5$ before winter.

• Asian Journal of Turfgrass Science
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• v.17 no.1
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• pp.13-17
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• 2003

This study was conducted to figure out the effect of KOB Soil on creeping bentgrass‘Cobra’, Kentucky bluegrass (KB)‘Midnight’75% + Perennial ryegrass (PR)‘Palmer III’25%. This experiment was conducted from September 1, 2001 to August 31, 2002 at Hwajoulryong in Jeongsun County, Gwangwon-do. Treatments were Sand 80% + Peatmoss 20%, Sand 80% +KOB-Soil (No. 1) 20%, and Sand 80% +KOB-Soil (No. 2) 20%. Treatments with KOB Soils was superior to control fer the leaf length, number of leaf, turf quality and root length in Creeping bengrass and Kentucky bluegrass + Perennial ryegrass.

• Asian Journal of Turfgrass Science
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• v.9 no.3
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• pp.213-223
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• 1995

The study is aimed to understand effects of ethephon(lmg/1), ABA(0.lrng/l), BA(0.lmg/l). and NAA (0.lmg /1) soaking treatment on the seed germination of perennial ryegrass 'Dandy', creeping bentgrass 'Penlinks', tall fescue 'Arid' and kentucky bluegrass 'Nasaw'. These experiments are carried in vitro and their results are summarized as the followings ; In case of ethephon (lmg /1) soaking treatment of seed, the early germination of tall fescue 'Arid' and perennial ryegrass 'Dandy' was good without the soaking times. creeping bentgrass 'Penlinks' and kentucky bluegrass 'Nasaw' obtained the best results at 12 hr. soking treatment, and the longer the soaking time, the higher the germination percentage. The early germination percentage of tall fescue 'Arid' and perennial ryegrass 'Dandy' increased more highly at ABA(0. tmg /1) soaking treatment than at the control. The germination percent-age of creeping loentgrass 'Penlink' and kentucky bluegrass 'Nasaw' had respectively the best results at 6hr. and l2hr. soaking treatment. The early germination percentage of tall fescue 'Arid' and kentucky bluegrass 'Nasaw'increased more highly at BA (0.lmg /1) soaking treatment than at the control, and especially had the best results in 6hr. soaking treatment. perennial ryegrass 'Dandy' had the best results at l0min. soaking treatment, and the longer the soaking time, the lesser the germination percentage. The early germination of perennial ryegrass 'Dandy'. creeping bentgrass 'Penlinks' and tall fes- cue 'Arid' increased more highly at NAA (0.lmg /1) soaking treatment than at the control, and especially had the best results at l2hr. soaking treatment. However, the germination of Kentucky bluegrass 'Nasaw' seeds inhibited at NAA (0.lmg /1) soaking treatment. Key words: Ethephon, ABA, BA, NAA, Soaking treatment, Seed germination.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.176-179
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• 1999

Trinexapac-ethyl[ 4-(cyclopropyl- $\alpha$ -hydroxy-methylene)-3,5-dioxocyclohexane carboxylic acid ethylester] is a growth-retardant for plants by inhibiting a key step in biosynthesis of GA. A treatment of trinexapacethyl generally induces a reduction in vegetative growth and also inhibits heading. In addition, the trinexapacethyl was known to enhance the freeze-tolerance in annual bluegrass, however, the mechanism is not known yet. One possible reason for the enhanced freeze-tolerance may be the antifreeze protein known to be accumulated in intercellular space of the leaf during cold acclimation. In order to see the possible in-duction of the synthesis of antifreeze proteins by trinexacpacethyl, the apoplastic proteins extracted from Kentucky bluegrass treated with trinexapacethyl were analyzed by SDS-PAGE and the presence of the antifreeze protein was observed. In addition, western analysis showed the identity of the protein induced by both a cold acclimation and a trinexapacethyl treatment. It appears that an enhanced freeze-tolerance of the turf grass by trinexapacethyl is due to the synthesis and/or accumulation of the antifreeze protein similar to the enhanced freeze tolerance induced by cold acclimation.