• Journal of The Korean Society of Grassland and Forage Science
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• v.26 no.2
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• pp.105-112
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• 2006

This experiment was carried out to investigate the distribution, function of dry matter and competition in the grassland composed with mainly perennial ryegrass. Co-functions between grasses and weeds were evaluated by calculating methods; expected yield (P), agressivity, relative yield total (RYT), compensation index (CI) and morphological index (MI). Each values obtained were influenced by seeding method, grassland management and seasonal changes of co-functional index were identical. Expected yields of spring were lower than those of fall and improved by additional seeding to grassland in early spring time. In the relative yield total (RYT), all were under 1.0 which ranged from 0.17 to 0.41. Compensation index (CI) ranged from -0.3 to -0.6 and all values showed 'under compensation(+, --)' This means that the conditions of 'under compensation' could be improved through weed control by management of grassland in perennial ryegrass grassland. The results indicated that productivity of grassland mainly composed with perennial ryegrass is negatively affected by weeds like shepherd's purse, crabgrass and barnyard grass. As major weeds, shepherd's purse in spring, crabgrass in summer and barnyard grass in summer and fall were negatively functioned to productivity in the grassland composed with mainly perennial ryegrass.

• Weed & Turfgrass Science
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• v.2 no.1
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• pp.55-61
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• 2013

This study was carried out to investigate the morphological and soil characteristics of Zoysia spp. native to South Korea. Samples [41 ecotypes of Zoysia japonica, 28 ecotypes of natural hybride between Z. japonica and Z. sinica (Junggi), 22 ecotypes of Z. sinica, and 8 ecotypes of Z. matrella] were collected in seashores, levee and summit of the rock in southern Korea. Variations in leaf width, plant height, leaf angle, length of leaf sheath, leaf trichome, stolon length, and seed shape were measured at collection sites and experimental plots. Among the entries, most of the measurements did not show any significant differences between natural and experimental plot except for leaf angle of Z. sinica and the number of seeds per spike of Z. matrella, which might be caused by different environmental conditions. Soil pH was 6.0 at the most of the collection sites. $Mg^+$ was 0.06-0.02 $cmol{_c}^+kg^{-1}$, $Mg^{2+}$ was 0.09-0.03 $cmol{_c}^+kg^{-1}$, and $K^+$ was 0.02-0.007 $cmol{_c}^+kg^{-1}$ at most zoysiagrasses growing soils.

• Korean Journal of Weed Science
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• v.16 no.2
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• pp.160-170
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• 1996

Several physiological responses were investigated in plants treated with TOPE as a preliminary step to know its action site. Unlike photo-dependent diphenylethers, herbicidal activity of TOPE appeared slowly and its typical symptoms were both burning of leaf blades and abnormal division of meristem in grasses, Similarly, both leakage of cell electrolytes and the curling of cotyledon margin were also shown in cucumber(Cucumis sativus L.). Biosynthesis of chlorophyll in etiolated cucumber cotyledon was not inhibited directly by treatment of TOPE at low light intensity(5.5${\mu}$ mol $m^{-2}s^{-1}$ PAR) and protoporphyrin IX was not also accumulated. The contents of phytoene, phytofluene and ${\beta}$-carotene were abnormaly increased. Photosynthesis was inhibited only at high concentration. Mitochondrial respiration was inhibited at high concentration but rather increased significantly at 10${\mu}$M of TOPE. However, respiration inhibitors did not alleviate the two symptoms of TOPE in cucumber cotyledon. In the same experiments, using inhibitors of protein or nucleic acid biosynthesis, only one of the two symptoms was alleviated by chloramphenicol and cycloheximide. In contrast, both symptoms were alleviated by actinomycin-D and hydroxyurea, suggesting that nucleic acid metabolism might be preferentially related to the mode of action of TOPE. DNA, RNA and protein contents were accumulated in both cucumber cotyledon and rice (Oryza sativa L.) routs treated with TOPE, and the DNA of them was increased at first. Thus, it is conjectured that TOPE increase nucleic acid metabolism directly or indirectly, and then disturb various metabolic pathways causing abnormal physiological and morphological effects followed by final death.

• Korean Journal of Weed Science
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• v.30 no.4
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• pp.421-428
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• 2010

A foliage contact herbicidal substance was separated from ethyl ether fraction in n-hexane extract of Saussurea lappa roots and identified as dehydrocostus lactone [(3aS,6aR,9aR,9bS)-3,6,9-trimethylidene-3a,4,5,6a,7,8,9a,9b-octahydroazuleno[5,4-d]furan-2-one](DHCL). When DHCL at 4,000 ppm was foliage-applied to two grasses and two broadleaf plants, greater than 85% necrotic injury was obtained from large crabgrass, maize and soybean, whereas only about 40% necrotic injury appeared in black nightshade, indicating that DHCL has no gross morphological selectivity, but shows difference in contact response among the plant species tested. Conductivity in incubation medium of the leaf disks treated with DHCL increased as the incubation time continued. Relatively low contact injury in black nightshade as compared with the other three plant species tested was attributed to decrease in absorption of DHCL due to relatively high amount of cuticle. DHCL did not require light in the herbicidal action and there were no inhibitory effects on seed germination and cell elongation. Acetyl-CoA carboxylase activity was inhibited by 30% and 58% at $100\;{\mu}M$ and $1000\;{\mu}M$ DHCL, respectively. These results suggested that the herbicidal action of DHCL was related with inhibition of fatty acid synthesis which in turn caused to weaken cell membrane integrity.

• Weed & Turfgrass Science
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• v.5 no.4
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• pp.230-235
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• 2016

Miscanthus are perennial rhizomatous grasses and considered as an ideal cellulosic bioenergy crop. Recently, it was reported that Miscanthus was damaged by the larvae of rice stem borer, Chilo suppressalis Walker, one of the most destructive pests of rice in Korea since the 1960s. This study was thus conducted to evaluate the insecticidal effects against rice stem borer in the Miscanthus cultivation fields for two years. The experiment consisted of four chemical agent plots, one environment-friendly agent plot, and untreated plot. Untreated plot showed significantly high damage of 50%, while Buprofezin Tebufenozide and Carbosulfan Methoxyfenozide treatment plots showed low damage rate of 2% with low larvae density of 1 and $2.3larvae\;m^{-2}$, respectively. Damage rates of Tebufenozide, ChlorantraniliproleIndoxacarb, and environment-friendly agent(MatrineWood vinegar solution) were 15, 26, and 18%, respectively, which were lower than that of untreated plot but higher than those of Buprofezin Tebufenozide and Carbosulfan Methoxyfenozide. In conclusion, rice insecticides were effective against rice stem borer in Miscanthus field. In particular, the treatments with Buprofezin Tebufenozide and Carbosulfan Methoxyfenozide showed excellent control effects with control value of 93.3 and 95.2. However, further studies with different types of insecticides should be carried out for the selection of insecticides with more effective control of rice stem borer.

• The Korean Journal of Pesticide Science
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• v.8 no.1
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• pp.1-7
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• 2004

Fenoxaprop-p-ethyl[Ethyl (R)-2-{4-(6-chloro-1,3-benzoxazol-2-yloxy)phenoxy}propionate] is well known as a herbicide for its specific activity against the weed grasses. This compound was synthesized by the reaction of 4-(6-chloro-1,3-benzoxazol-2-yloxy)phenol and ethyl (S)-O-(p-toluenesulfonyl)lactate in good yields with high optical pure(optical purity: 99.9% up). In this process Walden inversion occurs, whereby the S-configuration of the propionic acid derivative is converted to the R-configuration of the final product. 4-(6-Chloro-l,3-benzoxazol-2-yloxy)phenol was obtained by 5 step reactions in over-all 70% yields using inexpensive raw materials.

• Weed & Turfgrass Science
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• v.6 no.1
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• pp.67-76
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• 2017

The study was initiated to evaluate the effects of overseeding warm-season grass (Zoysia japonica Steud.) with cool-season grasses (CSG) on turfgrass density, uniformity and tiller appearance and to determine turfgrass species and seeding rate applicable for a practical use. Treatments were comprised of Kentucky bluegrass (KB, Poa pratensis L.), perennial ryegrass (PR, Lolium perenne L.), tall fescue (TF, Festuca arundinacea Schreb.) and their mixtures. Overall turfgrass density and uniformity were much better with the overseeded treatments over the control. In early stage after overseeding, the greater the PR in treatments, the greater the turfgrass density and uniformity. But the higher the KB, the lower the density and uniformity. From the middle-stage evaluation, however, we observed the opposite results as compared with early-stage findings. Accordingly, the KB was highest in turfgrass density and uniformity, while the PR lowest. In regards of mixtures, both turfgrass density and uniformity were better with increased KB and decreased PR in overseeding rates. As for a medium-quality mixtures of Korean lawngrass with CSG, it would be the best choice to apply with KB at $50g\;m^{-2}$ and equal combination of KB, PR and TF by 1/3 in mixing at $75g\;m^{-2}$ in terms of sustainable density and uniformity.

• 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.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.1
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• pp.61-70
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• 2008

The object of this experiment was to investigate the food habits of sika deer fed with various roughage sources. The feeding trials were conducted at Chungnam National University and Unbong Animal Genetic Resources Station in 2007. The experimental roughages sources were five including 25 species in all; grass sources; 5 species(Lolium perenne, Festuca arundinacea, Poa pratensis, Agrostis alba and mixed grass), legume sources; 5 species(Trifolium pratense, Medicago sativa, Trifolium repens, Melilotus officinalis and Vicia villosa), browse sources; 5 species(Quercus serrata Thunb., Prunus jamasakura Sieb., Quercus aliena Blume, Robinia pseudoaccacia and Pinus densiflora), weed sources; 5 species(Artemisia princeps Pampanini, Erigeron canadensis, Alopecurus aegualis Sobolewski, Echinochloa crusgalli var. frumentacea(Roxb.) Wight and Rumex crispus), and native grass sources; 5 species(Zoysia japonica Steudel, Agropyron tsukushiense var. transiens(Hack) Ohwi., Arundinella hirta(Thunb.) Tanaka, Miscanthus sinensis Anderss and Phragmites comunis Trin). Five sika deer were selected which had nearly the same body weight(average 92.5kg) as experimental animal. Experimental roughages were prepared by 0.5kg(DM basis) per 1 species fed to sika deer, and the experiment was carried out from 08:00 to the next day 06:00. The chemical composition and dry matter digestibility of each roughage source and species were significantly different at the sampling area, plant species, growth stages and cutting period. The sika deer ate more roughages which had low fibrous contents, but high dry matter digestibility. Among all the 25 species of roughages, the favorite intake species ranking by sika deer was observed like this: Quercus aliena Blume, Prunus jamasakura Sieb, Quercus serrata Thunb. and Trifolium pratense, respectively, and the lower intake species was Phragmites comunis Trin. On the other hand, compared to each roughage source, total intake amount by sika deer was showed as browse(36.5%), Legumes(34.2%), grasses(14.0%), native grasses(13.5%) and weeds(1.8%), respectively. Based on the result, the food habits of sika deer seems to be closer to typically browser type.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.2
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• pp.119-128
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• 2008

The object of this experiment was to investigate the food habits of Korean native goats fed with various roughage sources. The feeding trials were conducted at Chungnam National University and Unbong Animal Genetic Resources Station in 2007. The experimental roughages sources were five including 25 species in all; grass sources: 5 species (Lolium perenne, Festuca arundinacea, Poa pratensis, Agrostis alba and mixed grass, legume sources: 5 species (Trifolium pratense, Medicago sativa, Trifolium repens, Melilotus officinalis and Vicia villosa), browse sources: 5 species(Quercus serrata Thunb., Prunus jamasakura Sieb., Quercus aliena Blume, Robinia pseudoaccacia and Pinus densiflora), weed sources: 5 species(Artemisia princeps Pampanini, Erigeron canadensis, Alopecurus aegualis Sobolewski, Echinochloa crusgalli var. frumentacea (Roxb.) Wight and Rumex crispus), and native grass sources: 5 species(Zoysia japonica Steudel, Agropyron tsukushiense var. transiens(Hack) Ohwi., Arundinella hirta(Thunb.) Tanaka, Miscanthus sinensis Anderss and Phragmites comunis Trin). Ten Korean native goats were selected which had nearly the same body weight(average 30.6kg, 남) as experimental animals. Experimental roughages were prepared by 0.5kg per 1 species fed to Korean native goats, and the experiment was carried out from 08:00 to 20:00. The chemical composition and dry matter digestibility of each roughage source and species were significantly different at the sampling area, plant species, growth stages and cutting period (p<0.05). The Korean native goats ate more roughages which had low fibrous contents, but high dry matter digestibility. Among all the 25 species of roughages, the favorite intake species order by Korean native goats was observed like this: Quercus serrata Thunb., Quercus aliena Blume, Trifolium repens, and Pinus densiflora and Artemisia princeps Pampanini which was lower intake compared to other domestic herbivores. On the other hand, compared to each roughage source, total intake amount by Korean native goats was showed as browse(29.9%), legumes(23.0%), weeds(21.6%), grasses(21.5%) and native grasses(4.0%), respectively. Based on the result, the food habit of Korean native goats seems to be closer to browser type.