• Weed & Turfgrass Science
• /
• v.1 no.4
• /
• pp.76-79
• /
• 2012

This study provides basic information on morphological characteristics of zoysia mite, Aceria zoysiae and symptom in zoysiagrass for turfgrass management in golf courses. Zoysiagrass mite distributed from Pocheon, Gyeonggii province to Jinju, Gyeongnam province and damaged turfgrasses from spring to fall. Damaged leaf by zoysiagrass mite was rolled unidirectionally and mite damaged leaves in the inside of rolled part. Leaves was turned to yellow and damaged area formed irregular yellow patch.

• The Plant Pathology Journal
• /
• v.38 no.3
• /
• pp.182-193
• /
• 2022

Turfgrass, the most widely grown ornamental crop, is severely affected by fungal pathogens including Sclerotinia homoeocarpa, Rhizoctonia solani, and Magnaporthe poae. At present, turfgrass fungal disease management predominantly relies on synthetic fungicide treatments. However, the extensive application of fungicides to the soil increases residual detection frequency, raising concerns for the environment and human health. The bacterial volatile compound, 2,3-butanediol (BDO), was found to induce plant resistance. In this study, we evaluated the disease control efficacy of a combination of stereoisomers of 2,3-BDO and commercial fungicides against turfgrass fungal diseases in both growth room and fields. In the growth room experiment, the combination of 0.9% 2R,3R-BDO (levo) soluble liquid (SL) formulation and 9% 2R,3S-BDO (meso) SL with half concentration of fungicides significantly increased the disease control efficacy against dollar spot and summer patch disease when compared to the half concentration of fungicide alone. In field experiments, the disease control efficiency of levo 0.9% and meso 9% SL, in combination with a fungicide, was confirmed against dollar spot and large patch disease. Additionally, the induction of defense-related genes involved in the salicylic acid and jasmonic acid/ethylene signaling pathways and reactive oxygen species detoxification-related genes under Clarireedia sp. infection was confirmed with levo 0.9% and meso 9% SL treatment in creeping bentgrass. Our findings suggest that 2,3-BDO isomer formulations can be combined with chemical fungicides as a new integrated tool to control Clarireedia sp. infection in turfgrass, thereby reducing the use of chemical fungicides.

• Asian Journal of Turfgrass Science
• /
• v.24 no.2
• /
• pp.199-204
• /
• 2010

Much of the coal ash by thermal power plant has gradually been increased, however researches on the recycling of bottom ash has not been investigated enough so far. In this research, the lysimeter test was conducted to find out the possibilities of bottom ash as soil amendment to improve the physiochemical properties of sandy topsoil of turfgrass in golf course. The turfgrass growth test and leaching test were conducted on the lysimeter. The lysimeter columns were manufactured with various topsoil mixing ratios of 0, 10, 20, 30, and 50% of bottom ash with sand. As a result of leachate analysis through the lysimeter column, the higher ratios of bottom ash mixed affect significantly on water holding capacity of topsoil sand media with decreasing of the percolation rate. The results of leachate analysis in every three days interval, the pH of leachate increased with the bottom ash ratios, but the volume of $NO_3$-N, $NH_4$-N and K decreased significantly. However, the level of EC of leachate had constantly maintained. These results indicate that the application of bottom ash may improve turfgrass growth with water holding capability and fertility of sandy topsoil. However, the negative effects of the bottom ash also evaluated by reducing water permeability and solubility of $PO_4$-P by adsorption into soil particles. The results indicates that the reasonable mixing ratio of the bottom ash as soil amendment should be less than 20% (v/v) with sand which has a low water-holding and fertility in golf course topsoil layers.

• Asian Journal of Turfgrass Science
• /
• v.26 no.1
• /
• pp.67-71
• /
• 2012

Organic fertilizers are divided into natural organic and synthetic organics. The benefits of natural organic fertilizer were reported from the previous researches. The previous researches have reported that clippings are nitrogen source for turfgrass growth. However, the limited research results about clippings as a source of natural organic fertilizers were reported. The objective of the research to investigate effects of liquid fertilizer produced from fermented clippings for creeping bentgrass growth. Liquid fertilizer (LF) produced was used for the research to be compared with urea and two natural organic fertilizers of different source (NO-1 and NO-2). Kentucky bluegrass (Poa pratensis L., Midnight) was used for the study. Turfgrass quality was measured by visual evaluation every two weeks from June to October, 2011 using a scale of 1 to 9 (1=worst, 6=acceptable, and 9=best). LF produced greater turfgrass quality than acceptable quality, especially with the summer period while urea and NO produced lower turfgrass quality than acceptable quality of 6. LF had less quality alteration than urea and NO during the study. Based on the result of the study, LF are more stable to maintain turfgrass quality than urea and NO.

• Weed & Turfgrass Science
• /
• v.2 no.3
• /
• pp.292-297
• /
• 2013

Winter turfgrass injury is one of the critical problems of many golf courses in Korea. Turfgrass loss from freezing injury due to low temperature leads to many types of damages including weed invasion, increased herbicide cost, increased soil erosion, and expensive re-establishment. Although Kentucky bluegrass (Poa pratensis L.) which is the most widely used among cool-season grasses in Korea is well known as cold tolerance species, freezing injuries to Kentucky bluegrass during winter are often found. Protecting the turfgrass crown is necessary to recover from low temperature stress in winter because shoots and roots can be recovered from the crown. Turf covers may protect the crowns from direct low temperatures and desiccation. Six different turf covers were installed to cover Kentucky bluegrass during a period of low temperatures. Turf covers had positive effects for spring green-up of Kentucky bluegrass based on the study. Applying any type of turf covers on Kentucky bluegrass resulted in an increase average and minimum temperature compared to the uncovered plot. Among turf covers, clear PVC film without holes produced the longest root length and the highest turfgrass quality.

• Proceedings of the Turfgrass Society of Korea Conference
• /
• 2005.04a
• /
• pp.16-19
• /
• 2005

• Weed & Turfgrass Science
• /
• v.5 no.2
• /
• pp.101-104
• /
• 2016

Curvularia leaf blight of creeping bentgrass (Agrostis stolonifera) putting green by caused Curvularia trifolii was observed in Hapcheon, Korea. In July to September 2014, curvularia leaf blight developed on leaf blades of creeping bentgrass as small water-soaked lesions that subsequently turned into dark-colored, necrotic spots. The spots were expanded and became gray, grayish-brown, or light brown, circular to oblong lesions with purple to dark brown borders that often were surrounded by a yellow halo. The necrotic lesions coalesced, became irregular in shape and caused tip or complete blighting of the leaves. Blighted leaf blades appeared grayish-white to tan. The fungus was identified by morphological characters and 16S rDNA sequencing as C. trifolii. Conidia of the pathogen were short, with predominantly 3-septa, straight or often curved, with end cells frequently paler than intermediate cells. Size of the 3-septate conidia in culture are $26{\sim}28{\times}11{\sim}12{\mu}m$. Pathogenicity of the fungus was proved by artificial inoculation on the host. This is the first report of C. trifolii causing leaf blight on creeping bentgrass in Korea.

• Korean Journal of Soil Science and Fertilizer
• /
• v.50 no.2
• /
• pp.127-134
• /
• 2017

Bottom ash (BA) has different macro- and micronutrients such as B, Mo, Fe, Ca, and Mg, providing useful resources for plant growth and soil quality. The objective of this study was to evaluate the applicability of artificial top-soil treated with BA in park area as a vegetation base material, especially for turfgrass growth. Collected BA was mixed with peat moss and clay at the ratio of 70:10:20 (w/w). In order to evaluate the park quality and turfgrass growth in park area, the artificial soil was applied with BA along with the control or without BA. Result showed that exchangeable K and P were increased by $11.4mg\;kg^{-1}$ and $163mg\;kg^{-1}$, respectively, compared to the control soil when the artificial soil was treated with BA. Microbial population and enzyme activity (Acid-phosphatase, APA) in artificial soil having BA also increased as 2 times and 10%, respectively, compared to the control soil. Comparing turfgrass growth and yield between general soil and artificial soil, about 2 times higher plant yield (fresh weight) was observed as artificial soil was applied comparing to general soil. Furthermore, nutrient concentration in turfgrass was averaged as 0.440% for $P_2O_5$, 0.456% for CaO, 1.198% for $K_2O$ and 0.188% for MgO that all values are higher than general soil (0.323% for $P_2O_5$, 0.416% for CaO, 0.610% for $K_2O$ and 0.173% for MgO). Application of BA can be useful for vegetation base material in park site.

• Weed & Turfgrass Science
• /
• v.4 no.4
• /
• pp.405-412
• /
• 2015

Forty schools having natural turf playgrounds were investigated by on-spot investigation and oral interviews with relevant school officials to find out basic information on turfgrass management practices of school playgrounds in Gyeonggi province. Average area of playground was $3,890m^2$ per school and $12m^2$ per student. Ninety five percent of turf playgrounds were managed by school staff and ninety percent of schools spent less than 5 million won per year for turf management. The difficulties in turfgrass management were considered as a major challenge for the schools, followed by turfgrass management cost. Among the management practices, school officials pointed out weed management as the most difficult work, followed by irrigation. The average number of fertilization and mowing was 2 and 6 times per year, respectively. About the half of playgrounds were irrigated only when there was wilting symptom. Zoysiagrass was the most popular choice for the school playgrounds and only three school playgrounds were established with pop-up irrigation system. Fourteen school playgrounds had good turf quality but the rest of school playgrounds had inadequate turf quality requiring minor or full renovation.

• Asian Journal of Turfgrass Science
• /
• v.19 no.1
• /
• pp.1-16
• /
• 2005

This study was conducted to effect a complex fertilizer treatment on a recovery of damaged turfgrass caused by competing with tree at area under trees, and to seek for effective management system on damaged areas under trees in golf courses. Available phosphorous and potassium were enough to grow up turfgrass in plots of East valley and Ji San Golf Club. But these plots were acid soil ranged from pH 5.3 to pH 5.5, so that lime fertilizer was required for improving the chemical of soil. The effect on complex fertilizer showed significant f3r the recovery of damaged turfgrass. Turfgrass recovery ratio by complex fertilizer was better in low-density(LD) section of fertilizer than in high-density(HD) section of control. As the result of surveying turfgrass characters according to dates, dry matters in HD sections of control plots were higher than these in LD sections of fertilizer plots in 6 Aug. before sprinkling a complex fertilizer. But dry matters in LD section of fertilizer were, on the contrary, higher than in 6 Sep. after sprinkling complex fertilizer. In view of the result so far conducted, a turfgrass recovery to LD sections of complex fertilizer was batter than that of HD sections of control. Sprinkling complex fertilizer on turfgrass damaged by competing with trees will maintain the turfgrass growth, even though happen to compete between trees and turfgrass.