• Asian Journal of Turfgrass Science
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• v.21 no.2
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• pp.177-182
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• 2007

When a football field is constructed using sand medium, the fertilizer management has to be adjusted because of the low nutrient holding capacity and higher leaching rate. The objective of this study was to test the effects of slow release fertilizers on Kentucky bluegrass (Poa pratensis L.) growth in simulated sport field rootzones with PVC pipe pots. Data of turfgrass color, uniformity, growth rate, biomass above ground, and the nitrate content in the leaching solution was collected at different growing stages and during four simulated rain fall periods. The result showed that the nutrient release rate of urea was the highest and that of controlled release nitrogen fertilizer was the lowest. Effects of the controlled release nitrogen fertilizer lasted 14 days more than other lawn fertilizers and 28 days longer than regular urea with acceptable quality levels of turf. The slow release fertilizer also restrained excessive growth of the grass, reduced the times of mowing. Slow release fertilizer used in this study reduced $NO_3$-N leaching by almost 50% at the beginning of turf establishment.

• Asian Journal of Turfgrass Science
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• v.22 no.1
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• pp.49-56
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• 2008

This study was conducted to evaluate effect of liquid fertilizer contained medium of Lactobacillus confusa and Pichia anoala on growth of creeping bentgrass(Agrostis palustris Huds. CV. Pennlixs). By application method of liquid fertilizer, the experiment plot was designed as following; NF was non-fertilized treatment, control was applied with compound fertilizer and treatment 1(T-1), treatment 2(T-2) and treatment 3(T-3) were applied with compound fertilizer and liquid fertilizer solution diluted 500, 300 and 100 folds, respectively. The every treatments was arranged a randomized complete block with three replications. Compared with NF, leaf color index of control, T-1, T-2 and T-3 in creeping bentgrass was increased 7.4%, 7.5%, 77% and 7.2%, respectively and chlorophyll content of T-1, T-2 and T-3 in creeping bentgrass was increased 45.7%, 45.6%, 52.1% and 49.6%, respectively, and T-2 and T-3 was increased 4.4% and 2.7% more than control. Dry weight of T-1, T-2 and T-3 was increased 2.7%, 13.8% and 13.9% more than control, when compared to control. These results were found that turfgrass qualities and growth was improved in treatment applied to compound fertilizer and solution of liquid fertilizer diluted 300 folds.

• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.4
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• pp.54-61
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• 2014

This study was conducted to investigate the effect of Actinomyces sp. and Bacillus sp., United States granular microorganisms and Japan granular microorganisms on turfgrass growth and thatch decomposing of creeping bentgrass in golf course by measuring turf color index, chlorophyll index, thatch content of soil, root length, turf density and chemical properties and thatch content of soil. Fertilizer treatment was designed as follows; control(CF; compound fertilizer), microorganism medium(M; CF+M), microorganism medium and livestock manure fertilizer(M-L; CF+M+LMF), microorganism medium, livestock manure fertilizer and amino acid liquid fertilizer(M-L-A; MM+LMF+ALF), United States granular microorganisms(USGM; CF+USGM), Japan granular microorganisms(CF+JGM). Soil properties investigated after experiment was scarcely affected by applied fertilizers in root zone of creeping bentgrass. The turf color index and chlorophyll index of M, M-L, M-L-A, USGM, JGM treatment were higher than those of CF. The turfgrass root in M-L treatment was longer than others. The thatch content of soil in M treatment was longer than others. The thatch content of M was decreased than that of CF by 6.8%. These was suggested that application of M induced the development of quality and growth of creeping bentgrass by assisting turfgrass growth and thatch decomposing.

• Asian Journal of Turfgrass Science
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• v.10 no.1
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• pp.1-11
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• 1996

Fifty accessions in Zoysia species and forty-one hybrid lines were evaluated in order to detect analyze the genectic variation of Zoysiagrasses and to obtain the basic information for breeding. 1.Plant height ranged from 13 to 34.5cm, leaf length from 7 to 26cm, leaf width from 2 to 7mm, and first leaf height from 1.1 to 8.5cm 2. The correlations among plant height, leaf length and first-leaf height were high, but leaf Width was correlated only With leaf length. 3. Stolon length was varied from 10 to 108cm, number of stolons from 12 to 53, internode length from 2 to 6.1cm and coverage percentage from 10 to 90%. 4.There were correlation among stolen length, number of stolons, internode length and coverage percentage except between stolen and internode length. 5.M1J and MC2 showed the highest level in stolen length, number of stolons and coverage percentage. Therefore they will be the best breeding materials for the purpose of fast covering. 6.According to the analysis on October 26, 1995, yellow color-change rate of leaves ranged from 5 to 85%, red color-change from 0 to 75% and sum of yellow and red change from 20 to 95%. Speciallty M2M1 and FL-41 kept green color untill early December, indicating that they had the late dormancy. 7. Visual assessment of stolon length and number of stolons, showed similar tendency With actually measured data. 8. Shoot density was very high in M2M1 and S2, and showed negative correlation with leaf width. 9. It is known in Korea that the darker green color of lawngrass is, the better it looks. There were 11 lines with dark green color leaves such as J 85-10, Meyer in Z. japonira, one asacession in Z. matrella and M2M1, M2S8, JM2, 55C2 in hybrid lines.

• Asian Journal of Turfgrass Science
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• v.26 no.2
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• pp.123-128
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• 2012

Kentucky bluegrass (Poa pratensis) is most widely used in golf courses and athletic fields. Weakness of Kentucky bluegrass is shallow root zone and has weak tolerance to shade. One of the biggest disadvantages is high demand of water. Water content is important factor to maintain excellent color and quality of turfgrass. There are two irrigation methods which are 'deep and infrequent (DI)' and 'Light and frequent (LI)'. The objective of the study is to investigate Kentucky bluegrass growth treated by different irrigation frequency. Three irrigation frequency were made; no irrigation, every other day, and weekly. The same amount of water was used between every other day and weekly irrigation except no irrigation. No irrigation mean no artificial water supply and precipitation only. No irrigation treatment produced turfgrass quality lower than acceptable rating of six in July and August. Under the weather condition of 2011, no irrigation could not maintained acceptable turfgrass quality. No significant differences were found for Kentucky bluegrass quality between DI and LI.

• 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.

• Horticultural Science & Technology
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• v.34 no.2
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• pp.342-353
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• 2016

This study was initiated to evaluate green color retention under three different soil systems. Several turfgrasses were evaluated in multi-layer, USGA, and mono-layer systems. Turfgrass entries were comprised of three cultivars of Korean lawngrass (Zoysia japonica Steud.) as warm-season grass (WSG) and three blends and three mixtures of Kentucky bluegrass (KB, Poa pratensis L.), perennial ryegrass (PR, Lolium perenne L.), and tall fescue (TF, Festuca arundinacea Schreb.) as cool-season grass (CSG). Significant differences were observed in visual turf color and green color retention among soil systems and turfgrasses. Both the multi-layer and USGA systems were highly associated with better color ratings and longer color retention, as compared with the mono-layer system. Seasonal variation of visual turf color greatly occurred from late December to early spring. CSG exhibited longer color retention than did WSG. The latter maintained green color for approximately 6 months, regardless of the soil system. Spring green-up of Korean lawngrass occurred from early to middle May, while it underwent discoloration from late October to early November. Among the CSGs green-up occurred between early March and early April and leaf color was maintained until middle December to early February. Therefore, the CSGs were green for 8.5 to 11 months, depending on turfgrass and soil system. The mean period of green color duration across all soil systems was approximately 10-11, 9-10 and 8.5-9.0 months for PR, KB and TF, respectively. As for the CSG mixtures, the greater the proportion of PR, the longer the green color retention, while the higher the proportion of TF, the shorter the color retention. There was greater variation in green color duration among the CSGs than the WSGs. Across soil systems, color retention differences of 2 to 6 days were observed for the Korean lawngrass, but 7 to 36 days for the CSGs. These results demonstrate that green color retention varied greatly according to soil systems and also among turfgrasses. Selections of turfgrass and soil system should be made using a concept-oriented approach, when establishing garden, park, soccer field, golf course and other sports field. Information obtained in this study can be used to select soil systems and turfgrasses based on the expected degree of leaf color retention.

• 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.

• Weed & Turfgrass Science
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• v.2 no.3
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• pp.306-311
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• 2013

Pythium blight occurred by Pythium aphanidermatum on chewing fescue cv. "Jamestowm II" from early June, 2010 and 2011 at the test field in Daegu University in Gyeongbuk Province, Korea. Disease symptoms on the turfgrass were leaf blights dying from the leaf tip and root rot, which appeared patches of brown to dark brown color or gray brown color in the field. The pathogens (40-1 isolate) of Pythium blight was isolated from the diseased leaf and crown tissue and cultured on potato-dextrose agar (PDA) for identification. Lobulate sporangia were inflated, complex structures, and filamentous sporangia were usually indistinguishable from vegetative hyphae. Sequences of ribosomal RNA gene of the fungus were homologous with similarity of 100% to those of P. aphanidermatum isolates in GenBank database. Pathogenicity was also confirmed on the chewing fescue, creeping betgrass and Kentucky bluegrass by Koch's postulates. This is the first report of Pythium blight on chewing fescue caused by P. aphanidermatum in Korea.

• Weed & Turfgrass Science
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• v.7 no.2
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• pp.130-139
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• 2018

The colors of packaging of herbicides and non-selective herbicides on the market in Korea are defined as brown and red, respectively, according to the notification of RDA. The present study aimed to understand consumer's electroencephalographic (EEG) response when looking at brown and red colors of herbicide and non-selective herbicide packaging papers. The EEG cap was placed on the scalp of each participant (men and women, 10 to 20 years old) and white (control) - brown - white - red colors were sequentially displayed for 5 seconds using the computer monitor. The EEG was measured and statistical analysis was performed using SPSS. For the brown color of the herbicide, men showed a decrease in concentration and a distracting response due to a decrease in the ratio of mid beta to theta (RMT) and the spectral edge of frequency (SEF90). In women, an increase in the ratio of SMR to theta (RSMT) and the spectral edge frequency 50% of the alpha (ASEF) was observed in different brain regions and these EEG changes may enhance the relaxation, stabilization and awakening states of the brain. For the red color of the non-selective herbicide, ASEF increased psychological stability in men. In women, a decrease in absolute high beta (AHB) may associate with a decrease in attention state of the brain. Overall data of the present study clearly revealed that the colors of two herbicides showed significantly different EEG response and gender difference.