• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.4
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• pp.263-268
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• 2013

We investigated the range of linoleic acid concentrations in different forage species and harvest stages. The linoleic acid concentrations in main cultivated grasses and forage crops were analyzed at three harvesting dates in Korea. The experiment compared 19 species of main grasses and forage crops, including eight species of grasses (Perennial ryegrass, Reed canarygrass, Tall fescue, Timothy, Bromegrass, Kentucky bluegrass, Orchardgrass and Wheat grass), six legumes (White clover, Red clover, Sweet clover, Crimson clover, Alfalfa and Hairy vetch) and five forage crops (Italian ryegrass, Barley, Rye, Oat and Rape) in Korea with three cuts (8 May, 19 May and 28 May). The linoleic acid concentrations of Reed canarygrass and Timothy were the highest, and Bromegrass was the lowest among the grass species. All grass species had high concentrations of linoleic acid at the late May harvest stage but were low at the mid May harvest stage. Legumes had higher linoleic acid concentrations than those of grasses, and harvesting in mid-May resulted in the highest linoleic acid concentration. Rape had the highest linoleic acid concentration and rye showed high concentrations of linoleic acid when compared with those of forage crops. All species of grasses and forage had decreased linoleic acid concentrations by the harvest stage. We have demonstrated opportunities to change the composition of ruminant products through breeding, selection, and management of grasses for altered levels of linoleic acid as a precursor to conjugated linoleic acid.

• Journal of The Korean Society of Grassland and Forage Science
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• v.6 no.1
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• pp.38-43
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• 1986

This field experiment was conducted to determine the effects of shading degrees (0 : full sunlight, 25, 50 and 75%) on the early growth characteristics and winter survival of grasses. For the test different artificial shading houses were established and pasture species used were orchardgrass, timothy and perennial ryegrass. The experiment was performed at Livestock Experiment Station in Suweon, and sowing date was Aug. 25, 1984. The results are summarized as follows : 1. Generally, root length, new root length, number of new root and tillers of grasses were increased at 0% (full sunlight) of shading, followed by 25, 50 and 75% of shading degrees, in that order. Plant length and leaf elongation, however were increased at 50% of shading, followed by 75, 25 and 0%. 2. The percentage of winter killing of grasses was significantly (P<0.05) increased as the shading degrees increased. Also the percentages of winter killing were 10.1% in orchardgrass, 9.5% in timothy and 14.2% in perennial ryegrass, respectively. 3. A significant negative correlations were observed in the relationship between winter killing and tillers, new root length and number of new root of grasses. However, there were positive correlations between winter killing and plant length or leaf elongation under shading conditions. 4. As the shading degrees are increased by 0, 25, 50 and 75%, the NAR of grasses was tended to be decrease to 10.98, 11.52, 9.81 and 6.12 g/$m^2$/day, in that order. Also there was a negative correlation (r=-0.5943*) between winter killing and NAR of grasses, and NAR of orchardgrass, timothy and perennial ryegrass were 8.58, 8.53 and 11.71 g/$m^2$/day, respectively.

• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.2
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• pp.68-75
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• 1991

A series of tests was carried out to determine the purity and germination of pasture plant and forage crop seeds imported in 1986 and 1987 at the grassland and forage laboratory, College of Agriculture, Seoul National University, Suweon. At the same time, the results obtained were compared with the National Livestook Cooperatives Federation(NLCF1's seed standards as a guide for determining seed quality. 1. The germination percentages of Potomac orchardgrass, Fawn tall fescue, Aquila Ky bluegrass and California ladino clover among grasses and legumes tested were lower than those of the N1,CF's standards, but the germination percentages of forage crops were higher than those of the NLCF's standards. 2. The purity of Potomac orchardgrass and Aquila Ky bluegrass were relatively lower than those of the NLCF's standards. 3. The percentages of other crop seeds in Potomac orchardgrass, Fawn tall fescue, Aquila Ky bluegrass and Cayuse oats were lower than those of the NLCF's standards. 4. Percentage of inert matter in the seeds was lower compared with the NLCF's standards except Akela ' forage rape. 5. The seeds of Potomac orchardgrass, NK 367 sorghum hybrid and sorghum x sudangrass hybrids such as NC+855, G83F and TE Haygrazer were contaminated with one or more weed seeds. Rumex spp. was by far the most common weed in the seeds imported. The other weeds occurred at a low level were Rumex acestosella, Senecio jacobaea, Cirsium arvense and Cuscicta spp. 6. There were many variations in 1,000 seed weight among different species. A thousand seed weight of Aquila Ky bluegrass was 0.263g, but that of Tetrone Italian ryegrass, Akela forage rape and Pioneer 3160 sorghum x sudangrass hybrid was 3.875, 3.476 and 242.4578, respectively. 7. According to the fluorescence test of ryegrass seed, Tetrone Italian ryegrass was known as a true annual type, but an unknown cultivar produced in Cheju was contaminated with 6% of perennial ryegrass seed.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.5
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• pp.85-93
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• 2004

This study was carried out to find out the effect of cool-season turfgrass overseeding onto zoysiagrass(Zoysia japonica L.) for extending green color and solving traffic problem during dormant periods. Overseeding rates of cool-season turfgrasses were $10g/m^2$ of Kentucky bluegrass(KB1), $20g/m^2$of Kentucky b1uegrass(KB2), $60g/m^2$ of perennial ryegrass(PR), $80g/m^2$ of Tall fescue(TF), and $10g/m^2$ of Kentucky bluegrass + $10g/m^2$ of perennial ryegrass mixture(KB+PR) onto 2m${\times}$2m(width${\times}$length) zoysiagrass plots with 3 replications.1 to 9-sca1e of visual quality and visual color were measured after treatment, Consequently cool-season turfgrass overseeding gave a good performances of extending the green periods and enhancing the turf grass quality. KB1 and KB2 were found to be excellent performances for visual quality and visual color compared to PR, TF, KB+PR and control. KB2 showed better turf performances than KB1 within Kentucky bluegrass overseedings. Turfgrass color was kept up for 10 months by overseeding of cool-season turfgrasses(KB1, KB2, PR, TP, KB+PR) compared to about 5~6 months by zoysiagrass(Control). The visual quality and visual color of PR and TF showed good performances during a green-up period of spring, but decreasing tendencies through the summer.Percent diseases data revealed also higher ratings for PR and TF compared to for KB1 and KB2.

• Journal of the Korea Organic Resources Recycling Association
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• v.7 no.1
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• pp.1-12
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• 1999

The objective of this study is to improve the function of an artificial culture soil which was mixed mainly with alum sludge. The artificial culture soil was more efficient than the commercial culture soil for the growth of perennial ryegrass and bush clover. Artificial culture soil was prepared paper sludge(40%), alum sludge(30%), sewage sludge(20%), and compost (10%). This artificial culture soil had no adverse effect on phytotoxicity tests. The alum sludge gives some water holding capacity and cohesion strength to the soil enought to require no other addition of adhesive agents. The leaching of aluminum from the alum sludge was negligible even at very low pH(=2) due to the mixed compost.

• Asian Journal of Turfgrass Science
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• v.24 no.2
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• pp.117-124
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• 2010

Turfgrass survival and ocurrence of brown patch disease during summer season were investigated the forty six cultivars of cool season grasses in 6 species, popularly used in golf courses in Korea. Ocurrence of brown patch disease was evaluated two times in July. The percentage of turfgrass survival was investigated on Aug. 20 and on Sep. 20 in 2010. There were significant difference for the percentage of turfgrass survival and brown patch disease occurrence among cultivars. Brown patch disease caused by Rhizoctonia spp. and Pythium aphanidermatum with rDNA ITS were showed most susceptible in creeping bentgrass (Agrostis palustris Huds) cultivars and chewings fescue (Festuca rubra var. commutata Gaud) cultivars. The percentage of turfgrass survival during August to September was showed lower creeping bentgrass cultivars and chewings fescue cultivars than another cultivars. Among of 20 cultivars in Kentucky bluegrass (Poa pratensis L.) species were showed highest survival in cultivars of "Nuglade", "Cabernet", "Midnight II" and "Beyond". 6 cultivars of Tall fescue (Festuca arundinacea Schreb) were showed highest survival in cultivars of "Double sentry", "Inferno", and cultivars of "Accent II" in Perennial ryegrass (Lolium parenne L.) species.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.2
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• pp.88-94
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• 2002

This study was conducted to select suitable turfarasses for use at 2002 world cup soccer fields in Korea. A 1/1000 scale Inchon worldcup soccer dome was constructed for this research. Species and seeding rates of cool-season grasses used inside and outside the dome were Kentuck bleugrass 10g/$m^2$ (KB), Kentucky bleugrass 10g/$m^2$+ perennial ryegrass 10g/$m^2$ mixture (KB+PR) and Kentucky bleugrass 6g/$m^2$+tall fescue 14g/$m^2$+ perennial ryegrass 4g/$m^2$ mixture (KB+TF+PR). Warm-season grasses also used in this study were Zoysia japonica 'Anyangjungzii' (ZA) and Zoysia japonica 'Zenith'(ZZ) which were layed as sod. So, total 5 types of grasses were used inside and outside the dome. The rootzone was constructed by the multi-layer method(United States Golf Association method). The plots were designed by randomized block design. Cool-season grasses(KB, KB+PR, KB+TF+PR) were found to be better performers for visual rating and visual color than the zoysiagrasses(ZA, ZZ). There were no significant differences in turf performance within cool-season grasses, while ZA showed better turf performances than ZZ within zoysiagrasses. The green color was maintained for about 10 months in the col-season grasses(KB, KB+PR, KB+TF+PR) compared to about 5~6 months in the zoysiagrasses. Root length and density data revealed higher values for KB, KB+PR and KB+TF+PR compared to ZA and ZZ. Root performance of 22 was better than ZA within zoysiagrasses which was the opposite result of turf performances. There was also no significant difference between U performance inside and outside the dome. However, the decreasing tendency of turf quality inside the dome at the end of the study showed that more proper maintenance technology was needed inside the d[me. It could be concluded by this study that cool-season grasses(KB, KB+PR, KB+TF+PR) were more suitable turfgrasses than waits-season zoysiagrasses(ZA, ZZ) for use at 2002 world cup soccer fields in Korea.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.5 s.112
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• pp.83-93
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• 2005

Research was initiated to investigate turf performance under USGA soil system. USGA system 45 centimeters deep was built with rootzone layer, intermediate layer, and drainage layer. Six turfgrass entries were comprised of 3 blends and 3 mixtures from cool-season grasses (CSG). Turfgrass color and quality ratings were best in spring and fall, especially early May to early July and late August to early November. Kentucky bluegrass (KB) consistently produced the greatest performance, while perennial ryegrass (PR) the poorest. Intermediate turf performance between KB and PR was observed with tall fescue (TF). Among CSG mixtures it increased with KB but decreased with PR. There were considerable variations in summer turf Performance. No summer drought injury was found in KB and TF. However, PR showed poor performance through summer as compared with others. Among mixtures, it decreased with PR. It was suggested that PR mix in less than $20\%$ in the mixtures to have an acceptable quality in summer. Cultural intensity also affected it. With lowering mowing height, KB of rhizomatous-type in growth habit kept good quality, while PR and TF with bunch-type in growth habit poor quality. Mowing quality was greatly different among CSG. KB produced clean-cut surface, but PR unclean one. If had an intermediate mowing quality between KB and PR. A great difference in green color retention was observed among CSG. The longest CSG was PR that kept green for 339 days, while the shortest one TF for 267 days. KB continued to keep green for 290 days. The mixtures kept green in color for 292 to 315 days, depending on turfgrass mixing intensity. The greater the PR in content, the longer the green color duration. These results demonstrate that KB was the best and PR the worst among CSG grown in USGA system under a domestic climate, in regards of turf quality, color, mowing quality, summer turf performance and green color duration. KB and TF are most adequate for high-maintenance and low-maintenance area, respectively. In case of mixtures for high-quality turf, it was desirable to use KB-based mixture with PR of below $20\%$ in seeding rate.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.10
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• pp.1383-1388
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• 2001

To explore the factors restricting animal performance in relation to sward structure under a strip-grazing system, measurements of sward factors, herbage intake and milk production at 3 levels of herbage allowance were made on perennial ryegrass (Latium perenne L.) sward for 3 experimental periods. About 29%, 36% and 52% of the biomass offered was removed by grazing in high $(42kg\;OM{\cdot}day^{-1}{\cdot}head^{-1})$, medium $(30kg\;OM{\cdot}day^{-1}{\cdot}head^{-1})$ and low $(18kg\;OM{\cdot}day^{-1}{\cdot}head^{-1})$ herbage allowance plots. Live leaf material was much more affected by grazing under different herbage allowance levels than dead material or leaf sheath. Grazing with a low herbage allowance decreased the proportion of live lamina by 93% and live lamina density by 96% before grazing. The density of dead material plus sheath was decreased by 17% after grazing at a low allowance, while it slightly increased or remained constant in the plots applied with high and medium allowances, respectively. The highly significant (p<0.01) correlations between herbage allowance and proportion (r=0.94) and density (r=0.91) of live lamina in residual sward after grazing were observed. Daily herbage intakes in the plots with high and medium levels of herbage allowance were not significantly different at $15.3kg\;OM{\cdot}head^{-1}$ in average, whereas with low level it decreased to $13.9kg\;OM{\cdot}head^{-1}$. Daily milk production was significantly (p<0.05) declined from $22.3kg{\cdot}head^{-1}$ (at high herbage allowance) to $19.7kg{\cdot}head^{-1}$ (at low herbage allowance). The data obtained clearly indicated that herbage intake and milk production were highly affected by the characteristics of residual sward, which were closely related to the level of herbage allowance.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.2
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• pp.89-96
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• 2001

Carbohydrate and soluble protein reserves and regrowth characteristics in response to cutting height were investigated over four regrowth cycles of turf-type perennial ryegrass(Lolium perenne L. cv. preludeII). When the plants were at the full-vegetative stage (twelve weeks-old), three sequential defoliations at 3, 6 and 9 cm above the root base were imposed at 2-week intervals. Shoot dry weight in all three treatments continuously decreased with progressing regrowth cycle and the decreasing rate was higher as cutting height was lowered. TNC (total non-structural carbohydrate) in stubble at the end of the fourth regrowth cycle in 3, 6 and 9 cm cutting height decreased by 98%, 82% and 27%, respectively, comparing the initial content. TNC in roots also largely decreased with similar pattern in response to cutting height, whereas the absolute amount was much less compared to stubble. Soluble protein in stubble in 3, 6 and 9 cm cutting height decreased by 98%, 82% and 57%, respectively, at the end of fourth regrowth. A significant correlations between TNC (r=0.906) or protein (r=0.879) at the fourth defoliation and dry weight of regrowing shoots at the end of fourth regrowth were observed. these results indicated that cutting height closely influences the levels of organic reserves available for new growth, and that the levels of reserves might provide a useful tool as a determinant for regrowth dynamics.