• Korean Journal of Weed Science
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• v.18 no.2
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• pp.136-145
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• 1998

This study was conducted to determine the growth characteristics, and the effect of plant growth regulators on the sprouting and growth of purple nutsedge(Cyperus rotundus L.) in order to establish effective control system in lawn ground. The flowering of purple nutsedge was initiated 30 days after transplanting regardless of the transplanting time. Low temperature less than $10^{\circ}C$ after flowering was required for tuber formation, showing that the tuberization was related to air temperature. Shoot number and dry weight of underground portion of purple nutsedge was slightly affected by plant growth regulators such as benzylamino purine, abscisic acid, brassinosteroid and jasmonate. Imazaquin applied at 1, 2 and 3 weeks after transplanting induced multi-shooting and inhibited shoot growth indicating that the herbicide played a role as plant growth regulator at a concentration of 30 and 60g ai/10a. The greatest inhibition of purple nutsedge was obtained by pyrazosulfuron-ethyl as applied 1 weeks after transplanting, showing almost 100% control of purple nutsedge. Tuber of purple nutsedge composed of 61.83% of moisture, 31.60% of carbohydrates, 4.03% of crude protein, 1.57% of crude fat and 0.97% of crude ash.

• Weed & Turfgrass Science
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• v.7 no.2
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• pp.148-157
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• 2018

Research was initiated to evaluate four domestic and overseas organic soil amendments (SAs) on turfgrass groundcover and density and to provide basic information on practical sports turf establishment. This study was conducted in Agrostis palustris Huds. (CB) grown in sand-based root zone. A total of 20 treatments of SA+sand were prepared by mixing 10 to 50% (v/v). These amendments were SABP (Berger Peat), SAEP (Eco-Peat), SAGS (G1-Soil), and SAPP (Premier Peat). Turfgrass groundcover and density significantly varied with SAs, its mixing rate to sand and week after seeding (WAS). Cumulative turfgrass density was variable, but a great change occurred between 2 and 4 WAS. Turfgrass density at 2 WAS ranged from 36.7 (SABP 30) to 89.7% (SAGS 20), being 53.0% in differences among treatments. However, CB reached to carrying capacity around 6 WAS. Thus, most treatments were similar to 90% or so in density. At the end of study, overall groundcover ranged between 60.7 (SAEP 10) and 96.7% (SAPP 50). Proper mixing rate was variable with SAs, being 10 and 20% for SABP and SAGS, respectively. But the optimum rate was 50% for both SAEP and SAPP.

• Weed & Turfgrass Science
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• v.4 no.3
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• pp.256-261
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• 2015

Trampling stress in turfgrass fields caused by traffics often occurs in zoysiagrass (Zoysia japonica) fields including golf course. In order to know the influences of trampling stress on the growth and development of turfgrass, leaf and root growth, chlorophyll fluorescence, chlorophyll content and 2-DE protein analysis were conducted in the turfgrass plants subjected to various levels of trampling stress from 0 to $9,420J\;day^{-1}$ day. Shoot growth was more highly inhibited by trampling stress than root growth. Although root growth was affected by trampling with weak intensity, the highest root length was observed in the turfgrass treated with weak trampling ($1,570J\;day^{-1}$). Chlorophyll fluorescence (Fv $Fm^{-1}$) was drastically lowered by trampling stress with moderate intensity. Leaf number showed similar tendency with leaf greenness. The number was decreased as the trampling intensity was increased. Shoot dry weight was decreased showing a similar tendency with the result of shoot length. The specific protein expressions under weak trampling were related to the functions of stress amelioration. Heat shock 70 kDa protein 10 and oxygen-evolving enhancer protein 1 were the proteins increased positively under trampling stress.

• Korean Journal of Weed Science
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• v.14 no.4
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• pp.265-271
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• 1994

This study was conducted to determine the herbicidal activity, persistance, downward movement and effect on bentgrass of 7 dinitroaniline herbicides such as benefin [N-butyl-N-ethyl-2,6-dinitro-4-(trifluoromethyl) benzenamine], beslogine [N,N-dibutyl-2,6-dinitro-4-trifluoromethylaniline], prodiamine [2,4-dinitro-$N^3$,$N^3$-dipropyl-6-(trifluoromethyl)-1,3-benzenediamine], pendimethalin [N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine], trifluralin [2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl) benzenamine], ethalfluralin [N-ethyl-N-(2-methyl-2-propenyl)-2,6-dinitro-4-(trifluoromethyl) benzenamine], and oryzalin [4-(diprop-ylamino)-3,5-dinitrobenzene-sulfonamide) together with bensulide [O,O-bis(1-methylethyl) S-[2-[(phenyl-sulfonyl) amino]ethyl]phosphorodithioate] and siduron [N-(2-methylcyclohexyl)-N'-phenylurea) as the control. In addition, distribution of pendimethalin and benefin into bentgrass was also determined. Prodiamine, benefin, and pendimethalin at the 1/16 dose of the recommended rate showed very high herbicidal activity($LD_{90}$) on Digitaria sanguinalis, but ethalfluralin and bensulide showed $LD_{90}$ at the 1/4 dose of the recommended rate, showing difference in herbicidal activities among dinitroaniline herbicides. All the herbicides except for pendimethalin had the lower herbicidal activity in sandy soil than that of clay-loam soil. Benefin, beslogine, prodiamine, oryzalin, bensulide and siduron persisted in the soil for about 50 days, but pendimethalin persisted in the soil for about 35 days, and trifluralin and ethalfluralin for about 25 days. Ethalfluralin, oryzalin and bensulide were the most mobile(downward movement) of the 9 herbicides studied. Less mobility was observed in the turfgrass condition than that of the bare soil. Beslogine bensulide prodiamine and benefin had no injury effect on bentgrass(Agrastis atolonifera L., penncross creeping bent grass). However, herbicides like oryzalin, trifluralin and pendimethalin reduced the dry weight of bentgrass by 12%, 30% and 40%, respectively. No significant difference in distribution of pendimethalin and benefin into inner part of leaves, surface and wax layer of bentgrass was observed, and thus it seems that different phytotoxic effect between pendimethalin and benefin may be attributed to different metabolism and mode of action.

• Weed & Turfgrass Science
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• v.6 no.4
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• pp.333-344
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• 2017

This study was conducted to examine the effect of cool-season grass overseeding on the green period, turf quality and density in zoysiagrass lawn. Treatments were perennial ryegrass (PR) overseeding ($60g\;m^{-2}$) on medium-leaf type zoysiagrass, Kentucky bluegrass (KB) overseeding ($20g\;m^{-2}$) on medium-leaf type zoysiagrass and narrow-leaf type zoysiagrass, and no overseeding on medium-leaf type zoysiagrass. Overseeding of KB or PR effectively provided quality improvement of zoysiagrass lawn by extending green-period about one month in spring and two months in fall season. PR overseeding showed quick green cover within 2-3 weeks but decreased the quality of overseeded zoysiagrass lawn during the summer season. Whereas, KB overseeding showed slow green cover taking two to three month after seeding but provided stable and good turf quality throughout the years. KB or PR overseeding significantly increased the turf density of zoysiagrass lawn except the period of summer depression of PR. The ground coverage of cool-season grasses ranged from 30 to 80% with considerable seasonal variation. As a result, KB and PR have their strengths and weaknesses as an overseeding material. Thus, the use of KB and PR as a mixture would provide better overseeding performance in zoysiagrass lawn.

• Weed & Turfgrass Science
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• v.2 no.1
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• pp.47-54
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• 2013

The study was conducted to investigate early establishment characteristics and germination pattern of fine-textured fescues (FF) under natural room temperature and to analyze differences between alternative and natural conditions for a practical application. Six cultivars from Chewings fescue (CF), creeping red fescue (CRF), hard fescue (HF) and sheep fescue (SF) were evaluated in the study. Daily and cumulative germination pattern were measured and analyzed. Significant differences were greatly observed in germination pattern, days to the first germination, days to 60% germination, and germination percentage with environments, species and cultivars. Final germination rate was 29.7 to 80.0% under natural conditions. The first germination was initiated between 8 and 10 DAS (days after seeding) under natural conditions, being 3 to 4 days later as compared with ISTA conditions. Days to the 60% germination were 12.1 to 19.0 DAS, being 3.0 to 4.2 days slower than that under ISTA conditions. CF 'Jamestown II' was the fastest cultivar, while the slowest CRF 'Audubon'. Turf establishment speed was faster with CRF < SF < HF and < CF in order. Information on differences in germination characteristics and pattern between alternative and natural conditions would be practically useful for a golf course construction etc., when established with FF.

• Weed & Turfgrass Science
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• v.3 no.1
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• pp.29-40
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• 2014

Research was initiated to investigate early establishment characteristics and germination pattern of Kentucky bluegrass (KB, Poa pratensis L.). Fifteen cultivars were evaluated under alternative conditions (8 hours light at $25^{\circ}C$ and 16 hours dark at $15^{\circ}C$). Significant differences were observed in germination characteristics and germination pattern among KB cultivars. A final germination percentage differed in cultivars, being 75.25 to 89.50%. The first germination was initiated between 6 and 9 DAS (days after seeding). As for the first germination percentage, 'Brilliant' and 'Midnight II' produced 14.50% and 23.00%, respectively, while the others were most below 5%. Days to 75% germination were between 15.08 and 28.80 DAS. 'Excursion', 'Midnight II', 'Odyssey', 'Midnight' and 'Courtyard' were fastest. The slowest cultivar was 'Voyager II', being over 28 DAS, which were 13 to 14 days slower than the fastest ones. Considering the first germination percentage, days to the first germination, days to 75% germination, and germination pattern, 'Midnight II', 'Excursion' and 'Midnight' were regarded as excellent cultivars under alternative conditions. From this study, information on differences in germination characteristics and patterns would be practically useful for a golf course construction when established with KB.

• Weed & Turfgrass Science
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• v.6 no.3
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• pp.235-248
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• 2017

This study was initiated to investigate seed germinating vigor, germination speed, and establishment characteristics of Festuca species under natural conditions ($5-25^{\circ}C$). Germination rate was 62.0% in CRF 'Audubon' to 97.0% in TF 'Olympic Gold'. It was greater with TF over fine-type fescues, being TF>SF>CF, HF>CRF. The germination speed, measured as days to seed germination of 50% through 80%, was fastest with TF, medium to high with CF, medium with HF and SF, and slowest with CRF. However, it was approximately 4 days slower under natural conditions, as compared with that under alternative conditions ($15-25^{\circ}C$). Germination peak time was much faster with TF. It ranged from 0.73 to 1.84 days with TF, being 1.45 days in average. But it varied with 2.16 to 11.75 days among fine-type species. The peak time was longer in order of SFCF>SF>HF>CRF.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.4
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• pp.211-221
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• 2021

The Rabbit grass(Trifolium Repens, call it 'Clover') is a representative harmful plant of lawn, and it starts growing earlier than lawn, forming a water pipe on top of the lawn and hindering the photosynthesis and growth of the lawn. As a result, in competition between lawn and clover, clover territory spreads, but lawn is damaged and dried up. Damage to the affected lawn area will accelerate during the rainy season as well as during the plant's rear stage, spreading the area where soil is exposed. Therefore, the restoration of damaged lawn is causing psychological stress and a lot of economic burden. The purpose of this study is to distinguish clover which is a representative harmful plant on lawn, to identify the distribution of damaged areas due to the spread of clover, and to review of changes in vegetation before and after the eradication of clover. For this purpose, a time series analysis of three vegetation indices calculated based on images of convergence Drone with RGB(Red Green Blue) and BG-NIR(Near Infra Red)sensors was reviewed to identify the separation between lawn and clover for selective eradication, and the distribution of damaged lawn for recovery plan. In particular, examined timeseries changes in the ecology of clover before and after the weed-whacking by manual and brush cutter. And also, the method of distinguishing lawn from clover was explored during the mid-year period of growth of the two plants. This study shows that the time series analysis of the MGRVI(Modified Green-Red Vegetation Index), NDVI(Normalized Difference Vegetation Index), and MSAVI(Modified Soil Adjusted Vegetation Index) indices of drone-based RGB and BG-NIR images according to the growth characteristics between lawn and clover can confirm the availability of change trends after lawn damage and clover eradication.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.1
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• pp.68-79
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• 2017

The objective of study was to find the relationship in hilly pasture landscape expectancy and tourist's satisfaction on grassland facility. It was followed by literature reviews and visitors' survey in Daegwallyeong Yangtte Farm on 31, July, 2014. 367 respondents were analyzed by F-test, t-test, Chi-square and Fisher's Exact Test at 0.05 level after data screening process. Computing factors were sex, marital status, age, academic career and occupation. The results was as followed; First, major respondents group of survey were in oder of woman, forty years old group, married office worker, and university graduate. Second, the expectancy for grassland was significant difference in age, but pasture color expectancy was not significant difference in gender, age, educational background, marital status, and there was significant difference in favorite grassland type with age, marital status. Third, favorite fence type was not significant difference along with all group of participants. However, color and material of fence was significant difference in marital status. Fourth, preferred ranch road was significant difference with occupation and marital status. There was significant difference in favorite grassland type near ranch road along with age and occupation type. Fifth, the mean satisfaction was 3.6 point in 5.0. Therefore, all respondents were generally satisfaction in visited. Tourists were more interested in ranch landscape than experience or contacts to animal.