• Journal of the Korean Institute of Landscape Architecture
• /
• v.35 no.1 s.120
• /
• pp.88-93
• /
• 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
• /
• v.16 no.2
• /
• pp.75-83
• /
• 2002

The back-filled soil of the New Incheon International Airport construction site was reclaimed with sea sand in near the Young-Jong island. The primary study was carried out from August 1993 to June 1997 to study soil amendment and to select salt resistance turfgrass species. This study dealt with low maintenance area that included most part of open space of airport site. The second experiment, from October 1996 to August 1998, focused on soil amendment and selection of turfgrass species for alongside runway where turf area was maintained. Through two previous studies, propagation methods with zoysiagrass were tested for alongside runway and surrounding areas at 1998. The study of construction methods with zoysiagrass, vegetative propagation showed better results on visual quality and cover rating compare with seeding propagation. However, significant different between vegetative and seeding propagation was not showed on visual quality and drought tolerance after one year of plot establishment. The cover rating by seeding construction methods reached in excess of 70% of limitation suggested by the Incheon International Airport Cooperation. Zoysia net and sprigging net methods were the most suitable where there requires rapid and high rate of ground cover. Seeding propagation should be acceptable to obtain a resonable cover rating where there allows relatively longer period of completion. Therefore, it should be possible to attain a proper rating of ground cover on the site of open space, alongside runway or areas similar to the New Incheon International Airport which is being built on dredged seashore sand. However, the methods of soil amendment, selecting salt tolerance species, and proper construction procedure should be considered at the a time.

• Asian Journal of Turfgrass Science
• /
• v.16 no.1
• /
• pp.31-40
• /
• 2002

This study was conducted to analyze the correlation of soil physical properties and growth of turfgrass on the ground of Olympic-mainstadium. Soil hardness and turf visual quality were measured at 77 plots (10m x 10m divided each) independently and analyzed correlation later. Physicochemical properties of the topsoil analyzed from three typical levels of the severely, moderately, slightly compacted areas. The ground showed high hardness at the center circle and the goal line, but low at the end line areas. On the contrary, visual quality rate of turfgrass was low at the center circle and the goal line, but high at the end line areas. The correlation was shown a significant negative value on soil hardness between turf visual quality Soil hardness seems to be accelerated by the improper soil texture of sandy loam which contained a large amount of finer particle of silt (10.7%) and clay (11.1%) which values exceeded for USGA (United State Golf Association) recommendation. Deterioration of turf quality resulted initially from improper construction and followed by high soil compaction with continuous uses of the ground without proper maintenance. To perform the international quality of the turf ground, the initial construction procedures should be followed by standard specifications of sport ground.

• Asian Journal of Turfgrass Science
• /
• v.26 no.2
• /
• pp.89-95
• /
• 2012

Korean lawn grass, which belongs to Zoysia genus in Gramineae family, is one of the major turfgrass which is widely adapted to its native niches in the temperate region of the north east Asia through tropical regions including Philippine, Thailand and Australia. The Turfgrass Information Center' database provides 5,340 descriptive records including 638 referred papers and 1,370 technical reports concerning 'Zoysia'. The database focused on researches on golf courses and lawn care industries. The researches provide informations on seed technology and use of plant protectant for pest management in turf management industries. The purpose of this study is to analyze and classify the research contents of zoysiagrasses which have been published in Korean journals. The total number of research papers published in Korean journals were 274 including 102, 38, and 134 in the 'Botanical', 'Environmental' and 'Cultural' researches, respectively. Publication in foreign journals by Korean investigators were not counted in this research. Research fields concerning golf course maintenance and plant protectant are believed to be necessary when compared to international trends. Moreover, advanced research efforts for the development of new cultivars with various environmental and disease resistance should be accomplished.

• Asian Journal of Turfgrass Science
• /
• v.20 no.2
• /
• pp.167-174
• /
• 2006

This study was initiated to investigate the effect of chitosan on creeping bentgrass growth. Chitosan was applied several times in dilution of 300, 500 and 800 times at ten-day intervals after transplanting. Such growth characteristics as leaf length, root length, numbers of leaves, fresh weight and dry weight and chlorophyll content were observed. Treatment of 500 times diluted chitosan resulted in the longest root length, being 31.5cm while the control the shortest root of 25.1cm. Leaf numbers were 27.9 and 45.5, respectively for the control and the 300 times treatment. The highest chlorophyll content was associated with treatment of 300 times diluted chitosan and the lowest one with the control, resulting in 11.9 and $18.4mg/100cm^2$, respectively. We found that leaf number, chlorophyll content, fresh and dry weight were higher in the treatment of 500 times than the other treatments.

• Asian Journal of Turfgrass Science
• /
• v.5 no.1
• /
• pp.33-39
• /
• 1991

This experiment was carried out in order to study the changes of morphological characters of growth and thatch accumulation in perennial ryegrass as affected by the different levels of soil compaction and coring depth. Soil compactions were treated with 10, 20, 30 and 40kg power roller and artificial core depth were 2.5, 5.0, 7.5 and 10.0cm under the ground, respectively. And, artificial core space were fixed 84.5% in all soil compaction levels. The results obtained were summarized as follows: 1. Relationship between number of tillers and root weight was positive significant difference for soil compaction levels. 2. Relationships between shoot dry weight and thatch weight, and number of tillers were positively significant difference for artificial core depths. It may indicate that thatch accumulation depend on the growth of shoot, and increase of shoot dry weight as growth progressed may due to increase of number of tillers, respectively. 3. Soil compaction level of 20kg was greatly influenced on the growth of shoot in all artificial soil depths. Thus, shoot dry weight and number of tillers were obtained the highest value, but thatch and root weight were obtained the lowest values at the soil compaction level of 20kg. It was suggested that soil compaction of 20kg is very suitable rolling factor for turf maintenance. 4. Thatch weight was positively significant difference for the interaction of soil compaction levelXcoring depth.5. Thatch weight was positive significant correlated with root weight, and negative significant correlated with number of tillers by increase of soil compaction levels.

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

• Weed & Turfgrass Science
• /
• v.4 no.4
• /
• pp.368-375
• /
• 2015

Earthworm cast occurred in surface of turfgrass in golf courses which affect turfgrass maintenance and golf play. In this study several survey of seasonal fluctuation of earthworm cast in different golf courses (Anseong, Gapyeong, Gunpo and Yongin in Gyeonggi province, and Geumjeong in Busan) was done. A number of earthworm, soil temperature and moisture of detection site of earthworm cast in each golf course were also done. Cast occurred in different golf courses are found mostly from April to November on turf surface and the cast number varied in different month as well as in golf courses. In the same golf courses, a number of detected cast was difference from individual sites. A number of cast and earthworm was correlated. Also, in higher soil moisture showed the higher cast density in different golf courses. Soil temperature and moisture of detecting cast ranging from $2.1^{\circ}C$ to $33.1^{\circ}C$ and 4.9 to 44.1%, respectively. In case of cast, soil temperature level lies in between $10-15^{\circ}C$ where the highest soil moisture was 25%.

• Weed & Turfgrass Science
• /
• v.7 no.2
• /
• pp.140-147
• /
• 2018

In Korea, mowing the grass of a grave (Beolcho) is a very important event preceded by Chuseok (Korean thanks giving day) and Si-Hyang (annual ancestral feast). Because Beolcho usually takes place one or two weeks before Chuseok, the traffic accidents on roads are getting worse and safety accidents are getting more and more. Erroneous Beolcho methods can cause the soil to be exposed and cause the loss of soil or the low shoot density of graveyard grass or weed occurrence. Therefore, the dispersion of the Beolcho timing and the approprite method can be import issues. The present study assessed the effects of grass mowing timing and height before Chuseok on the growth of Zoysia japonica and Z. matrella. The mowing timing was evaluated at 1 week, 2 weeks, 3 weeks, and 4 weeks before Chuseok, and the mowing height differently according to the two type of grass. In Z. japonica, the faster mowing before Chuseok, the longer the plant height, and the coverage rate and shoot density were higher. In Z. matrella, the faster mowing, the longer the shoot length, but the coverage rate and shoot density did not show any difference or tendency. As compared to Z. japonica, the plant height of Z. matrella was kept short regardless of the time of mowing. In both grasses, the plant height was shortened when mowing was done at low cutting height, but the coverage rate and shoot density were decreased. In addition, it was shown that it is advantageous to maintain the shoot density of graveyard lawn by 40-50 mm or 30-40 mm cutting above the ground for Z. japonica or Z. matrella, respectively.

• Asian Journal of Turfgrass Science
• /
• v.23 no.2
• /
• pp.287-294
• /
• 2009

This study conducted to evaluate the growth characteristics of creeping bentgrass in summer after application of the plant growth regulator, Trinecapac-ethyl, and these data may provide basic information to golf course turf maintenance. The results showed that the shoot density of creeping bentgrass was increased an average density of 1.7 $ea/cm^2$ with the trinexapac-ethyl application, especially about 2 $ea/cm^2$ during the growth retarded period of June and July. The root length increased also in June and August. The visual quality was improved significantly with trinexapac-ethyl treatment all the experimental periods, moreover, the effect was significant by reducing a summer decline stress of creeping bentgrass during the warm and humid period of summer. The green speed was significantly improved by this growth regulator treatment and those effect was prominent during stressed season of late June to mid July. Overall of the result, we found that shoot density, visual quality and green speed of bentgrass green were improved by trinexapac-ethyl treated from early growing season of spring and these effects were continued during summer. It should be very beneficial to manage the bentgrass green in stressed season. In future, the possibility and efficiency of mixture with fungicides and/or fertilizers might be needed. The spring green-up test with trinexapac-ethyl will be followed in next spring.