• Asian Journal of Turfgrass Science
• /
• v.24 no.2
• /
• pp.138-144
• /
• 2010

This study was conducted to investigate the effect of Lactobacillus sp. and Saccharomyces sp. on turf quality, shoot and root growth of creeping betgrass in golf course by measuring turf color index, chlorophyll content, dry weight of shoot and root, T/R ratio and root length. Fertilizer treatment was designed as follows; nonfertilizer (NF), control (CF; compound fertilizer), microorganism medium(MO; CF+MO)), microorganism medium contained Fe(MO-Fe; CF+MO-Fe) and microorganisum medium contained S (MO-S; CF+MO-S). 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 MO, MO-Fe, MO-S treatment were higher than those of NF, and similar to those of CF. The turfgrass root in MO and MO-Fe treatment was longer than others. The dry weight of shoot in MO and MO-S was higher than CF and that of root in MO and MO-Fe, and dry weight of MO was increased than that of NF and CF, by 26% and 6%, respectively. AS compared with NF, T/R ratio of CF, MO, MO-Fe and MO-S was increased, and MO and MO-Fe was similar to CF, MO-S higher. Nutrient content in CF, MO, MO-Fe and MO-S was contained more than in NF, and it was higher in shoot. These was suggested that application of MO induced the development of quality and growth of creeping bentgrass by assisting root growth and nutrients uptake.

• Asian Journal of Turfgrass Science
• /
• v.24 no.2
• /
• pp.145-148
• /
• 2010

Nitrogen (N) is one of the most important nutrients among 17 essential nutrients for maintaining turfgrass color and quality. The slow release fertilizers were initially developed to provide a more consistent release of nitrogen over a longer period and are often used to decrease leaching potential from sandy soils. The goal of this study is to determine if various slow release N sources affect the rate at which turfgrass establishes. Six nitrogen sources were evaluated; Nitroform (38-0-0), Nutralene (40-0-0), Organiform (30-0-0), Sulfur coated urea (SCU, 37-0-0), urea (46-0- 0), and Milorganite (6-0-0). The root zone media was seeded and sodded with 'Limousine' Kentucky bluegrass (Poa pratensis L.). Sodded pots produced 182 to 518 g more clipping dry weight than seeded pots. Among seeded pots, Milorganite produced greater amount of root dry weight than any other N sources. Because the period of turfgrass growth is different between sodded and seeded plots, there were differences on clipping yield and root growth. Overall, high N rate had turf color greater than acceptable color of 6 among seeded pots throughout the study. However, low N rate didn't produce acceptable turf color throughout the study. Based on the result of this tudy, ilorganite would be ecommended for new establishment of Kentucky bluegrass an urea with less clipping yield which can lead to reduce abor.

• Journal of the Korean Applied Science and Technology
• /
• v.37 no.4
• /
• pp.1052-1065
• /
• 2020

This study analyzed the effects of professional baseball PPL advertising speed on brand awareness, brand attitude, and behavioral intention for professional baseball consumers. The purpose of this study is to present a method that can be used as a variety of marketing utilization strategies of professional baseball teams and parent companies. This study was conducted on 411 professional baseball consumers. For data processing, frequency analysis, reliability analysis, reliability analysis, and multiple regression analysis were performed using SPSS 25.0 Window Version. Then, the average variance extraction index (AVE) and construct validity (CR) were calculated to verify convergent validity and discriminant validity. In addition, confirmatory factor analysis (CFA) was performed using AMOS 25.0. As a result, first, it was found that entertainment, informativeness, and discomfort, which are sub-factors of PPL advertisement speed, have a significant effect on brand recognition. Second, entertainment, information, and discomfort, which are sub-factors of PPL advertising speed, have a significant effect on brand attitude. Third, entertainment, informativeness, and discomfort, which are sub-factors of PPL advertisement speed, have a significant effect on behavioral intention. Fourth, it was found that brand awareness and brand attitude have a significant effect on behavioral intention.

• 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.

• Korean Journal of Applied Biomechanics
• /
• v.16 no.3
• /
• pp.1-7
• /
• 2006

The Primary type of swinging motion in human movement is that which is characteristic of a pendulum. The two types of pendulums are identified as simple and compound. A simple pendulum consist of a small body suspended by a relatively long cord. Its total mass is contained within the bob. The cord is not considered to have mass. A compound pendulum, on the other hand, is any pendulum such as the human body swinging by hands from a horizontal bar. Therefore a compound pendulum depicts important motions that are harmonic, periodic, and oscillatory. In this paper one discusses and compares two algorithms of Newton's method(F = m a) and Euler's method (M = $I{\times}{\alpha}$) in compound pendulum. Through exercise model such as human body with weight(m = 50 kg), body length(L = 1.5m), and center of gravity ($L_c$ = 0.4119L) from proximal end swinging by hands from a horizontal bar, one finds kinematic variables(angle displacement / velocity / acceleration), and simulates kinematic variables by changing body lengths and body mass. BSP by Clauser et al.(1969) & Chandler et al.(1975) is used to find moment of inertia of the compound pendulum. The radius of gyration about center of gravity (CoG) is $k_c\;=\;K_c{\times}L$ (단, k= radius of gyration, K= radius of gyration /segment length), and then moment of inertia about center of gravity(CoG) becomes $I_c\;=\;m\;k_c^2$. Finally, moment of inertia about Z-axis by parallel theorem becomes $I_o\;=\;I_c\;+\;m\;k^2$. The two-order ordinary differential equations of models are solved by ND function of numeric analysis method in Mathematica5.1. The results are as follows; First, The complexity of Newton's method is much more complex than that of Euler's method Second, one could be find kinematic variables according to changing body lengths(L = 1.3 / 1.7 m) and periods are increased by body length increment(L = 1.3 / 1.5 / 1.7 m). Third, one could be find that periods are not changing by means of changing mass(m = 50 / 55 / 60 kg). Conclusively, one is intended to meditate the possibility of applying a compound pendulum to sports(balling, golf, gymnastics and so on) necessary swinging motions. Further improvements to the study could be to apply Euler's method to real motions and one would be able to develop the simulator.

• Asian Journal of Turfgrass Science
• /
• v.26 no.1
• /
• pp.54-59
• /
• 2012

This study was conducted to evaluate to the effect of liquid fertilizer with saponin (SLF) and liquid fertilizer with amino acid (ALF)on the growth of creeping bentgrass. In creeping bentgrass, turf color index, chlorophyll index, dry weight and shoot number were measured. It was hardly affected by SLF and ALF applications in investigation of chemical properties of the soil. By applying SLF and ALF, turf color index and chlorophyll index in 2SLF and 2ALF were increased more than CF, and shoot number and root length in 2SLF, ALF and 2ALF were higher than CF. In correlation coefficient among growth factors of creeping bentgrass, turf quality was significantly different in root length, shoot number, dry weight, and content of N and K in turf tissue (P<0.05), N content of tissue was significantly in root length, shoot number and dry weight (P<0.05), and K content was significantly in shoot number and dry weight (P<0.05). These results suggested that application of functional liquid fertilizers such as SLF and ALF was expected to replace compound fertilizer in turf management and that applied SLF and ALF was stimulated the uptake of N and K into turf so that turf qualities were improved by enhancing growth shoot and root of turf.

• Asian Journal of Turfgrass Science
• /
• v.20 no.1
• /
• pp.11-23
• /
• 2006

This study was carried out to propose low types of green speed expectation models for fast putting green management by changing mowing height($4.0{\sim}2.5$ mm) and timing of rolling, dew removal and dew removal+rolling. Ball roll distance data were taken from the creeping bentgrass(Agrostis palustris Huds. 'Penncross') practice green of east course at the Lakeside C.C. in October 18, 2001 and May 25, 2002. Data were subjected to multi-regression analysis using Statistical Package for the Social Science. Among four types of green speed expectation models, the best multiple-regression equation for fast green management was as follows; $Y_4=4.171-0.225{\cdot}X_1-0.038{\cdot}X_2$ (where, $Y_4$ : green speed(m) after single dew removal+single rolling, $X_1$ : mowing height($4.0{\sim}2.5,\;X_2$ : passage of time ($0{\sim}8$ h.)). The equation[single dew removal by using sponge roller $\rightarrow$ single mowing at 3.0 mm height or less $\rightarrow$ single rolling] explained to provide fast green over 3.2 m (Stimpmeter readings required for USGA championship play) until the end of first round. Therefore, this cultural practice system was believed to provide fast putting green condition for professional golf tournament

• Asian Journal of Turfgrass Science
• /
• v.20 no.1
• /
• pp.83-91
• /
• 2006

This research was initiated to enhance the tilth of fine-textured soil for turf growth by incorporation of crumb rubber shredded from used tires. A specific objective was to determine the physical properties of soil mixes amended with different grade and amount of crumb rubber in soils. Two soils and three different grades(3.5, 6.5 and 9.5 mm) of crumb rubber were used. The soils selected were an Arenzville silt loam(coarse-silty, mixed, nonacid, mesic Typic Udifluvents) and a Hosmer silty clay loam(fine-silty, mixed, mesic Typic Fragiudalfs). The amount of crumb rubber mixed in soil ranged from 0 to 0.4 $g{\cdot}g^{-1}$(using 0.05 $g{\cdot}g^{-1}$) increments and 0 as a control. For each treatment, soil cores were constructed following the recommendation by the United States Golf Association Green Section Record. Results indicated that porosity of the mixes decreased as the amount of crumb rubber increased. Regardless of the grade of crumb rubber, mixes with less than 0.15 $g{\cdot}g^{-1}$ of crumb rubber in fine-textured soil could not enhance their macro-porosity and hydraulic conductivity. However, as the amendment increased over 0.15 $g{\cdot}g^{-1}$, the tilth of the mixes had improved significantly macro-porosity, hydraulic conductivity and air permeability, as compared with a control.

• Asian Journal of Turfgrass Science
• /
• v.19 no.1
• /
• pp.39-46
• /
• 2005

The 21 strains of Korean entomopathogenic nematodes, {Heterorhabditis bacteriophora Hamyang strain(HbH), Heterorhabditis sp. 202, 205, 217, Heterorhabdiris sp. KCTC 0991BP strain, Steinernema carpocapsae Pocheon(ScP), S. longicaudum Gonaju, S. longicaudum Nonsan, Steinernema sp. 7,24, 52, 55, 60, 64, 206, 207, 209, 210, 219, and 227 strain} were evaluated for the control of a turfgrass insect pest, Exomala orientalis. Heterorhabditis spp. showed higher pathogenicity than Steinernema spp. against 3rd instar larvae of E. orientalis with $55\%$ mortality by Heterorhabditis sp. 202 strain and $50\%$ by HbH and Heterorhabditis sp.205 strain at the rate of 200 infective juveniles per larva 14 days later after treatment. The number of infective juveniles of Korean entomopathogenic nematodes in 3rd instar larvae of E. orientalis was higher in Heterorhabditis spp. than in Steinernema spp.. In general, numbers of produced infective juveniles of three species were much higher, i.e., Heterorhabditis sp.202 strain produced 273,064 infective juveniles, S. carpocapsae Pocheon strain 273,043, and Heterorhabditis sp. 217 strain 248,887, respectively.

• Asian Journal of Turfgrass Science
• /
• v.25 no.2
• /
• pp.202-207
• /
• 2011

Organic fertilizers are divided into natural organic and synthetic organics. The benefits of natural organic fertilizer were reported from the previous researches. 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). Creeping bentgrass (Agrostis stolonifera L., L-93) 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). Turfgrass disease damage was measured by percent of area damaged when a turfgrass disease occurred. LF produced lower damage than NO and urea when temperature was high. Although NO-2 produced the highest or equal to the highest turfgrass quality in June and October, LF had the highest or equal to the highest quality from July to September.