• 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.

• Asian Journal of Turfgrass Science
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• v.5 no.1
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• pp.11-22
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• 1991

This experiment was executed to investigate the possibility of the application of taxonomic method through the isoelectric focusing with polyacrylamide gel and sodium dodecyl sulfate-polyacrylamide gel electrophoresis with seeds in the identification of turfgrasses. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis was used to investigate the pattern of seed proteins which were extracted from 18 cultivars of cool season turfgrass and 4 cultivars of warm season turfgrass. The isoelectric focusing with polyacrylarnide gel was used to investigate the activity of the three isozymes of esterase, peroxidase and phosphoglucose isomerase which were extracted from 18 cultivars of cool season turfgrass and 4 cultivars of warm season turfgrass. The results were summarized as follows. 1. The difference of the patterns of seed proteins was observed with sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The identification of intra-genus was easily detected. 2. The three isozymes of esterase, peroxidase and phosphoglucose isomerase were investigated through isoelectric focusing with polyacrylamide gel. As a result, esterase was most effective among three isozymes in the identification of turfgrass cultivars 3. In the past cultivar identification was primarily based on visual morphological characters, but there was a lot of difficulty. If we should use electrophoresis, we will be able to identifvturfgrass cultivars more effectively.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.1 s.120
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• pp.88-93
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• 2007

Since the 1990s, the application of Kentucky bluegrass cultivars has increased in newly-constructed Korean golf courses as opposed to the previously-used zoysiagrass. However, there have been few reports studying the selection and characterization of these Kentucky bluegrass cultivars under Korean weather conditions. A total of 12 Kentucky bluegrass cultivars were tested for their adaptability in environmental stresses during summer conditions in Korea in order to select the best Kentucky bluegrass cultivars for use in Korean golf courses. This study found that two Kentucky bluegrass cultivars ('Midnight' and 'Bluestone') maintained their green throughout the summer season and had a high degree of root density, as compared to the other cultivars tested. These two cultivars also had a good rate of coverage in the early growth period. These characteristics make them suitable for application on sports fields and golf courses, which receive many divots and the frequent replacement of turfgrass sod caused by both biotic and abiotic stress. Two other cultivars, the 'Ginney' and 'Nuglade', also displayed good visual quality and high rate of coverage under summer conditions. In conclusion, the 'Midnight' and 'Bluestone' cultivars performed well in areas including the maintenance of their green color, the number of roots and the rate of coverage during the summer months. These characteristics are necessary for golf courses sports fields, which receive many divots and requirethe frequent replacement of turfgrass. further research on a range of Kentucky bluegrass cultivars, including a sensitivity test for many pathogens and recovery rates from a variety of stresses, is required in the near future.

• Asian Journal of Turfgrass Science
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• v.24 no.1
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• pp.50-55
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• 2010

Five turfgrass species and 46 cultivars were investigated for difference of spring greenup and living ground cover. Turf color and Normalized Difference Vegetation Index (NDVI) for greenup were investigated between species and cultivars. Turf color and NDVI were showed significantly different among species and cultivars. Turf color was showed significantly different among 20 cultivars of kentucky bluegrass (Poa pratensis L.). NDVI was significantly difference among 20 cultivars of kentucky bluegrass and 6 cultivars of tall fescue (Festuca arundinacea Schreb). The percentage living ground cover was showed significantly different among creeping bentgrass (Agrostis palustris Huds) cultivars and fineleaf fescue cultivars in spring.

• Asian Journal of Turfgrass Science
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• v.21 no.2
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• pp.155-161
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• 2007

This study was initiated to evaluate the growth characteristics of creeping bentgrass cultivars during the sprlng season. The green-up of 'CY' and 'T-1' were about 2 weeks earlier than the other cultivars followed by 'Penn A' 'Crenshaw', 'L> 'Penncross' > 'Putter' > 'Dominant' > 'SR1020' in that order. 'T-1' and 'CY-2' had the highest chlorophyll content while 'Penncross' had the lowest during the spring. 'Crenshaw' and 'Penn A-4' showed the highest shoot density in this research, followed by 'CY-2', 'L-93', 'T-1', 'Putter', 'Dominant', 'SR1020', and 'Penncross' in that order. In case of root length, 'CY-2' and 'L-93' were the best cultivars, but 'Penncross' was worst during the spring. 'CY-2' had the best visual quality among the cultivars, 'T-1' and 'Crenshaw' also classified as high visual quality group whereas 'SR1020', 'Dominant' and 'Penncross' were grouped in relatively low quality. In conclusion, 'CY-2', 'T-1' and 'Crenshaw' were the best cultivars in terms of growth characteristics in spring. Conversely, 'SR1020' and 'Penncross' were the poorest cultivars. These results can be more useful for management or constructing of golf courses. However, this research was performed with little compaction stress. More information is needed on the tolerance to compaction stress of these bentgrass cultivars.

• 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.9 no.3
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• pp.173-185
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• 1995

Hydroseeding technique is a very popular method of revegetating slope areas through the control of soil erosion and stability by seeding grasses. This study was conducted to select turfgrass species and cultivars for hydroseeding. Experiment plots were established on various soil types and environmental conditions at Singar-Ansan high-way construction site. The investigation was designed in three cutting, one back-filling and other three spare sites with various seed mixtures. Results indicated that combinations of seed mixtures influenced seed germination and rates of surface cover. In a view of long term, vegetation shifts should be influenced by characters of slopes and micro-climate conditions. Hydroseeding did not show good results on rocky slope areas. Revegetation was only going on where there had soil. The combination of seed mixture with a higher rate of perennial ryegrass had relatively good revegetation with faster germination and seedling growth. Improved turf-type tall fescue Arid ⓡ and Falcon ⓡ seemed to have good environ-mental adaptation and drought tolerance. Wild or old type cultivars showed relatively slow green-up in spring and growth rates at the next year of seeding. For the harmonious landscaping with surrounding area, the combination of native grass mixture with cool-season grasses had good results. Slow and low revegetation rate at hack-filling site seemed to be caused by the poor development of capillary tubes in sub-soil. It was shown that a high correlation between seed germination and revegetation rate, and between three-month later coverage rate and final rate. The evaluation of coverage rate after three month seems to he acceptable to decide the accomplishment of hydroseeding results on rode side slopes.

• Proceedings of the Turfgrass Society of Korea Conference
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• 2004.01a
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• pp.62-71
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• 2004

• Asian Journal of Turfgrass Science
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• v.21 no.1
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• pp.1-7
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• 2007

This study was initiated to evaluate the qualitative characteristics of creeping bentgrass(Agrostis palustris Huds.) cultivars for the climate In Korea through the NTEP(Nat'l Turfgrass Evaluation Program) data. 'L-93' showed the highest rating in overall mean visual quality. It was also the most prominent cultivar in seedling vigors, ground cover, and genetic color especially in summer. In case of turf texture, 'Penn A-1' and 'A-2' were the finest group, but the poorest group in cold tolerance. Leaf density and thatch accumulation were lower with 'Penncross', 'Pennlinks', 'Crenshaw', and 'L-93' as compared with 'Penn A'-type and 'G'-type cultivars. Resistance to moss invasion was greater with 'Penn A'-type and 'G'-type cultivars, but 'Penncross' was the least. These observations indicated that leaf density was considered to associate with the characters of turf quality, thatch accumulation and resistance to moss invasion. 'Penn A'-type cultivars were highly resistant to snow mold. Greater resistance to brown patch was associated with 'Penn A' and 'Penncross'. Higher resistance to pythium blight was found with 'Penncross' and 'Pennlinks'. 'L-93' showed higher resistance to dollar spot, but not to pythium. Therefore, these results demonstrated that turf maintenance program for the new bentgrass cultivars should be different from a conventional management for the cultivar of 'Penncross'.

• Asian Journal of Turfgrass Science
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• v.24 no.1
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• pp.24-30
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• 2010

We investigated occurrence of yellow patch for early spring season of 48 cultivars in 5 species of turfgrass, most popularly used in Korea golf courses. Only yellow patch disease caused by Rhizoctonia cerealis was occurred naturally from late fall season. Perennial ryegrass and creeping bentgrass cultivars showed susceptibility from yellow patch in early spring, respectively. However, among There was no significantly different between the other species. Creeping bentgrass, 'Pennlinks II' cultivar was the most susceptible. Yellow patch symptom showed reddish brown with margins in color and patch showed size from 5 cm to 50 cm in diameter. Based on our results, Yellow patch showed large differences among cultivar and each turfgrass species.