• Asian Journal of Turfgrass Science
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• v.25 no.1
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• pp.52-58
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• 2011

In order to investigate an artificially transition method of perennial ryegrass(Lolium perenne L. 'Accent') overseeded on zoysiagrass (Zoysia japonca Zenith') with Kerb (3,5-jichloro-N (1,1-dimethyl-2-propynyl). We observed turfgrass growth and physiological responses of the two turfgrasses under the shading treatments. The experiment was conducted in greenhouse during April- August. Shading was generally using a black shade net product whose the shade level was done into 0, 35 and 75%, actual light intensities were 589, 378 and $135\;{\mu}mol{\cdot}m^{-2}{\cdot}s$ PAR, respectively. The four levels of Kerb treatment were 0, 0.1 0.2, and $0.4\;g{\cdot}m^{-2}$. As shading was getting increased, growth of perennial ryegrass was increased slowly, but zoysiagrass was reduced and almost all of experiments showed significant differences statistically. Perennial ryegrass exhibited inclination that growth was reduced in more than Kerb $0.4\;g{\cdot}m^{-2}$ by shades. On the other hand, it was shown that the growth of zoysigrass was reduced by shades largely and it was not effected by Kerb. Through this study, it was determined that Kerb is effective for elimination of overseeded perennial ryegrass on zoysiagrass. Moreover, when excluding perennial ryegrass under the condition like shade, it is desirable for treating high concentration more than the basic processing amount.

• Asian Journal of Turfgrass Science
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• v.26 no.2
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• pp.83-88
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• 2012

When perennial ryegrass was overseeded in bermudagrass fairway, shoot density of perennial ryegrass was gradually increased to $88,000/m^2$ at the end of May, however dramatically decreased to 0 in September over the rainy season. On the other hand, that of bermudagrass increased from $2,000/m^2$ in March to $20,000/m^2$ in early June, and then decreased to $4,000/m^2$ at the end of July, after the rainy season, rapidly increased to $50,000/m^2$ in early September. Overseeding bermudagrass fairway with perennial ryegrass was maintained a good quality from mid-April to mid-June and decreased the quality over the rainy season from late June to July, and then turf quality was decrease to the worst level at the end of July. After the rainy season fairway quality was improved gradually and was the highest-level during September and early October. Trifloxysulfuron-sodium was treated to minimize the deterioration in turf quality due to early bermudgrass transition time in spring. Consequently, transition was started in mid-May and shoot density of bermudagrass treated by trifloxysulfuron-sodium was $70,000/m^2$ in mid-June. Even in the rainy season it was sustained as $30,000/m^2$, approximately three times higher than that of untreated overseeding fairway.

• Korean journal of applied entomology
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• v.41 no.3
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• pp.217-223
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• 2002

The chestnut brown chafer, Adoretus tenuimaculatus Waterhouse, is serious insect pests in golf courses. Adults feed on the leaves of latifoliate trees but larvae feed on roots of turfgrases such as bentgrass, Agrostis spp. Damage of A. tenuimaculatus larvae was observed at the Jinju golf club which showed damage symptom on perennial ryegrass, Lolium perenne in tees and fairways in July, 2000. Damaged turf by A. tenuimaculatus larvae became yellowish and wilted. Symptom of laval damage of A. tenuimaculatus was similar to summer depression in warm season turfgrasses but not recovered by irrigation when Korean isolates of entomopathogenic nematodes were evaluated for the control of A. tenuimaculatus larvae in laboratory and field as a possible biological control agent. The nematodes used were Heterorhabditis bacteriophora Jeju strain, Hererorhabditis sp. Gyeongsan strain, Steinernema carpocapsae Pocheon strain, S.glaseri Dongrea strain, and S.longicaudum Nonsan strain. In the laboratory test H.bacreriophora Jeju strain and Heterorhabditis sp. Gyeongsan strain were highly effective for 3rd instars with 95% mortality. In the field test reduction rates of A.tenuimaculatus larvae were higher by ranging from 28 to 57% by H. bacteriophora Jeju strain, Heterorhabditis sp. Gyeongsan strain, and S.carpocapsae Pocheon strain compared to 7% by natural cause.

• Korean journal of applied entomology
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• v.45 no.1 s.142
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• pp.67-74
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• 2006

Korean entomopathogenic nematodes were introduced into cultural management of turfgrasses to enhance white grub control in golf courses for saving labour and expenses and contribution to giving safe playing and working places for golfers and superintendents by environmentally friendly control strategy. The turfgrass height influenced efficacy of entomopathogenic nematodes. Efficacy was higher at short turfgrass both in pot using Galleria mellonella larvae and in golf courses using 2nd instar of Exomala orientalis and Ectinohoplia rufipes as baits. Aeration increased the efficacy of entomopathogenic nematodes which were lower virulent. Pre-aeration was more effective than post-aeration. Exomala orientalis larval population was reduced 80.4 and 66.0% in the pre-aeration and post-aeration with entomopathogenic nematode, Steinernema carpocapsae Pocheon strain compared to 35.4% in the no aeration treatment.

• Asian Journal of Turfgrass Science
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• v.25 no.2
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• pp.171-176
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• 2011

Sclerotinia homoeocarpa, the causal agent of dollar spot, is one of the most common pathogens of cool season turfgrasses in South Korea. The vegetative compatibility group (VCG) assay was carried out using nitrate-nonutilizing (nit) mutants recovered from 13 South Korean isolates with various geographical origins. The mutants were divided into four phenotypic classes based on mutation loci associated with nitrogen assimilation: nit1, nit2, nit3, and NitM. The recovered number of nit mutants greatly varied among the isolates, ranging from 0 to 15 mutants. Of the mutants isolated, nit1 and nit2 mutants were most common (80%) while NitM and nit3 were relatively rare. One dominant and four minor VCGs were determined from 18 mutant isolates tested. To study population structures of Korean S. homoeocarpa isolates and increase our understanding of its ecological and epidemiological aspects for dollar spot management on turfgrass, more generated mutants should be tested with more diverse isolate collections.

• Asian Journal of Turfgrass Science
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• v.23 no.1
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• pp.35-44
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• 2009

This study was carried out to examine the growth performance of 4 species of cool-season grasses and 4 species of zoysiagrasses under salt injury in Seo-san reclaimed area. Grasses were grown on the plots with capillary water interruption layer (WCWIL) and without capillary water interruption layer (WOCWIL) soil systems. Cool-season grass and seeding-type zoysiagrass plots were seeded on 6 Jun, 2006. Vegetative zoysiagrass 'Junggi' was established by sprigging and 'Senock' and 'Millock' were plugged. Electric conductivities of irrigation water (ECw) ranged from 0.28 to $3.3\;dS{\cdot}m^{-1}$. Electric conductivities (ECe) of the soil with capillary water interruption layer and without capillary water interruption layer ranged from 0.55 to $9.4\;dS{\cdot}m^{-1}$ and from 1.84 to $9.4\;dS{\cdot}m^{-1}$ respectively. Leaf color, turf quality, coverage rates, and growth rates were rated visually for 2 years. Zoysiagrass 'Junggi', creeping bentgrass, zoysiagrass 'Senock' and 'Millock' showed acceptable growth at salty fairway condition, while Kentucky bluegrass, perennial ryegrass, Kentucky bluegrass mixed with perennial ryegrass, and seeded zoysiagrass 'Zenith' showed establishment rates below 70%. These results will be useful when choosing turf grass species and cultivars for the golf courses in reclaimed land area.

• Weed & Turfgrass Science
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• v.3 no.1
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• pp.41-49
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• 2014

Four preparations of liquid turfgrass fertilizers were tested cool season turfgrasses during fall season. The preparations of PS-A, PS-B, PH-C and PH-D for commercial products were contained with essential nutrient elements, seaweed extract, amino acids, and humus substance. Growth and quality of creeping bentgrass (Agrostis palustris Huds cv. Penn-A1) and Kentucky bluegrass (Poa pratensis L.) mixture (Midnight 33%, Moonlight 33%, Prosperity 33%) were evaluated by normalized difference vegetation index (NDVI), root length and fresh weight, shoot density, turf color, and chlorophyll content. Three foliar sprays of 4 preparations with an interval of 7 days were made in the fall of 2013 in the sod production field at Hapchun, Korea. No significant difference among 3 preparations was found in NDVI of creeping bentgrass. However, PS-A was significantly increased NDVI of Kentucky bluegrass. Two to three applications of PS-A significantly increased chlorophyll content and turf color. Three foliar sprays of PS-A and PS-B were significantly increased the shoot density of Kentucky bluegrass on 20 days after final application. These results may indicate that the use of some preparation is beneficial in producing higher quality turfgrass sod with better color and chlorophyll content during fall season.

• Korean journal of applied entomology
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• v.39 no.3
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• pp.171-179
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• 2000

- Turfgrass insect pests and natura.l enemies for biological control were investigated to develop pest management effectively in golf courses at several golf clubs. Twenty eight insect pest species of 10 families in 6 orders were collected from golf courses. The zoysiagrass mite, Eriophyes zoysiae and root-knot nematode, Meloidogyne incognita were also collected from zoysiagrass. White grubs of several scarab beetles and cutworms (Agrotis spp.) damaged seriously at most surveyed golf clubs. In addition, bluegrass webworm (Crambus sp.), Japanese lawngrass cutworm (Spodoptera depravata), scale insects, Tipula sp., and ants (Camponitus japonicus, Formica japonica, and Lasins japonicus) damaged turfgrasses directly or indirectly in golf courses. The entomopathogenic nematodes, Heterorhabditis spp., Steinernema glaseri, and S. longicaudum, entomopathogenic fungi, Beauveria bassiana and Metarhizium anisopliae, and milky disease, Paenibacil/us popil/iae were isolated from white grubs or turfgrass soil as microbial control agents. Besides, dipteran predators, Cophinopoda chinensis, Philonicus albiceps, and Promachus yesonicus and hymenopteran parasitoid, Tiphia sp. were also collected. The P. yesonicus was the most active in golf courses. The root-knot nematode, M. incognita was found from Zoysia japonica, Z. matrella. and Cynodon dactylon.

• Journal of Applied Biological Chemistry
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• v.59 no.4
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• pp.331-336
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• 2016

Analytical methods for methiozolin in soil, water and turfgrass were established and dissipation patterns of methiozolin in soil and turfgrass were elucidated. Analysis was done using a high performance liquid chromatography with an ultra violet detector at the wavelength of 280 nm after extraction with acetone, liquid-liquid partition with dichloromethane, and a solid phase extraction purification. Limit of determination and Limit of quantitation were 1.0, 0.5, 1.0 ng, and 0.001, 0.1, 0.01 mg/kg for water, turfgrass, and soil, respectively. Recovery rates of methiozolin from soil, water, and turfgrass were ranged 87.5~111.3, 92.8~97.4, and 78.2~98.5 %, respectively. The turfgrass and soil samples were collected at 0, 1, 4, 7, 14, 30, 45, and 60 after spray on green area in golf course. Residues of methiozlolin were not translocated to lower soil layer but detected only in turfgrasses and root area of turfgrass. Half-lives of methiozolin in turfgrass were 10.7 days and 8.8 days in soil from root area.

• Korean Journal of Agricultural Science
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• v.6 no.1
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• pp.15-20
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• 1979

In order to determine the effects of different degrees of moisture stress on germination of various plant species, hundred seeds of six vegetables and six turfgrasses were germinated in petri dishes on filter papers moistened with water-mannitol solutions of 0, 2, 4, 8, 10, and 12 atmosphere osmotic concentration (degrees of moisture stress). The percentages and rates of germination of all species tested were generally decreased with: increase in moisture stress. Chinese cabbage and cucumber were quite resistant to physiological drought as the germination was not appreciably affected until moisture stress exceeded 10 atmosphere. However, increase in moisture stress decreased germination affecting most seriously tomato, carrot and squash. Weeping lovegrass, Italian ryegrass and perennial ryegrass germinated well at 10 atmosphere but the germination of Kentucky bluegrass, meadow fescue and orchardgrass was greatly reduced by increasing osmotic pressure. The result indicates that it may be possible to select drought resistant species and varieties by their ability to germinate in osmotic solutions.