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Lie is the position in which a golf ball comes to rest following a stroke. Although the lie of a golf ball is an important factor affecting the play of the next stroke, there have been few attempts to measure this characteristic or determine how management practices, turfgrass species, or cultivars affect ball lie. The objective of this study was to develop and demonstrate a new technique using digital image analysis for measuring ball lie in various turfgrasses. The technique uses a stage that positions a digital camera at the top of a mowed turfgrass canopy and collects an image of a golf ball positioned at the same focal length in each frame. The image was then subjected to digital image analysis to determine the percentage of the golf ball that was visible above the canopy. The new technique was calibrated by positioning a golf ball at a defined height above the soil and also compared with another published technique, called Lie-N-Eye, for accuracy and ease of use. The image analysis technique could distinguish changes in ball height within a turfgrass canopy. In addition, collecting data with the technique was easier and faster compared with the Lie-N-Eye, the only other method of ball lie analysis available. However, the two devices produced data that were highly correlated. Two cultivar trials of bermudagrass (Cynodon spp.) and zoysiagrass (Zoysia spp.) were evaluated using the technique, and significant differences among cultivars in both species were demonstrated. doi: 10.2135/cropsci2009.04.0233

Voltage collapse is a critical problem that impacts power system operational security. Timely and accurate assessment of voltage security is necessary to detect post-contingency voltage problems in order to prevent a large scale blackout. This paper presents an online voltage security assessment scheme using synchronized phasor measurements and periodically updated decision trees (DTs). The DTs are first trained offline using detailed voltage security analysis conducted using the past representative and forecasted 24-h ahead operating conditions. The DTs are also updated every hour by including newly predicted system conditions for robustness improvement. The associated synchronized critical attributes are obtained in real time from phasor measurement units (PMUs) and compared with the offline thresholds determined by the DTs to assess security. This approach is tested on the American Electric Power (AEP) system and properly trained DTs perform well in assessing voltage security. Several new ideas to improve DT performance are also introduced. Index Terms--Decision trees, online security assessment, phasor measurement units, voltage collapse.

Divot recovery has been investigated on many turfgrass species and a number of acceptable methods have been developed to simulate divots for those studies. In an effort to enhance the speed and reliability in simulating divot injuries, a divot-making machine was developed using a motorized lawn edger equipped with multiple saw blades stacked to a width similar to that of a divot. The uniformity of divots produced with this device was compared to two previously developed devices by cutting 30 divots with each device on three turfgrass species and measuring the width, length, depth, and area of each divot. On all turfgrass species, the device described here produced divots that were either as uniform or more uniform for length, width, depth, and area as the other two devices. In addition, the device can create divots five times faster than the other devices. This improved device should enhance the ability and ease of studying divot injury in the future.

As freshwater resources for turfgrass irrigation become more limited, the development of drought-tolerant turf cultivars will be of great value to turf managers. The objective of the following research was to evaluate the field drought tolerance of Kentucky bluegrass (Poa pratensis L.) cultivars and compare their drought tolerance to rooting capacity. Fifty bluegrass entries were established in the field in Albany, OR and evaluated during drought stress (irrigation withheld) events in 2005 and 2006. Drought tolerance was measured, using digital image analysis, as the number of days until a cultivar reached 50% green tissue. In both years, there was a wide range of cultivar responses to drought, with some cultivars losing 50% green tissue 23 d after irrigation was withheld, while others maintained 50% green tissue up to 45 d after irrigation was withheld. Several cultivars, including Mallard, Moonlight, Prosperity, SR2284, Brilliant, and Diva, demonstrated significantly better drought tolerance than other cultivars. Twenty of the cultivars tested under field conditions were also screened for shoot and root growth in a greenhouse study. There was no correlation between shoot growth, root growth, or root:shoot ratios when compared to drought responses in the field. These results demonstrate that there is wide variability in drought tolerance of bluegrasses but factors other than rooting capacity appear to be responsible for those differences.

Freshwater resources for turfgrass irrigation are becoming limited. Hence, the development of drought tolerant turf cultivars will be of great value to turf managers. The objective of the following research was to evaluate the field drought tolerance of turf-type tall fescue (Festuca arundinacea Schreb.) entries that were selected based either on high root/shoot ratio under greenhouse conditions or under severe drought stress conditions in the field. Twelve tall fescue entries (two selected by root/shoot ratio, two selected by screening field drought tolerance, the four parents, and four standard controls) were established under a rain-out shelter, and their green turf coverage was evaluated during drought stress (irrigation withheld) and drought recovery (irrigation reapplied) events in 2003 and 2004. In both years, entries selected for high root/shoot ratio demonstrated significantly improved drought tolerance compared to their parents, whereas improved drought tolerance for field-selected entries was less consistent. Turf green-up following drought conditions was correlated to the drought tolerance of each entry, in that those cultivars that were the most drought tolerant were also the first to green up on rewatering. These results validate that selecting germplasm based on high root/shoot ratio in the greenhouse is a viable method for improving the field drought tolerance of turftype tall fescue.

Techniques using digital image analysis have been recently developed to evaluate turfgrass stands for percent green cover and average color. Manually analyzing digital images may become cumbersome and tedious if turf field trials contain many plots or if images are collected at frequent intervals for analysis. The objective of the following work was to develop a user-friendly macro capable of automated batch analysis of an unlimited number of digital images. A macro named 'Turf Analysis' was written to batch analyze images using SigmaScan Pro software. The macro, which requires less than 1 min of manual execution, performs percent cover and/or color analysis on an unlimited number of images and automatically saves the results into a spreadsheet file. The macro is freely available to download., HISTORICALLY, field experiments investigating turfgrass have been evaluated by visual ratings. Although relevant information may result from such evaluations, final inferences may be questionable because of the subjective nature in [...]

Color is a major component of the aesthetic quality of turf and often evaluated in field studies. Digital image analysis may be an improved, objective method to quantify turf color. Studies were conducted to determine if digital image analysis with SigmaScan software (SPSS, Chicago, IL) was capable of: (i) accurately determining the hue, saturation, and brightness (HSB) levels of Munsell Plant Tissue color chips, (ii) quantifying visual color differences among zoysiagrass (Zoysia japonica Steud.) and creeping bentgrass {Agrostis palustris Huds. [= A. stolonifera var. palustris (Huds.) Farw.]} plots receiving various N treatments, and (iii) quantifying genetic color differences among bermudagrass (Cynodon spp.) cultivars. Digital images of turf plots were analyzed with SigmaScan software to determine average HSB levels for each image. A dark green color index (DGCI) was created from HSB values for direct comparison with visual ratings. Digital image analysis accurately quantified the HSB levels ([r.sup.2] = 0.99, 0.96, and 0.97, respectively) of Munsell color chips corresponding to turf colors. Significant HSB differences were present among N treatments in creeping bentgrass, while only significant hue differences existed in zoysiagrass. Significant hue and saturation differences were present among bermudagrass cultivars. There was strong agreement between DGCI values and visual ratings. The relative variances of the HSB and DGCI were significantly less than the variance associated with multiple raters. This evaluation technique may facilitate objective comparisons of turf color across researchers, locations, and years when images are collected under equal lighting conditions (i.e., the use of an artificial light source at night or in an enclosed system)., TURF COLOR is a key component of aesthetic quality and a good indicator of water and nutrient status (Beard, 1973). Therefore, color is often evaluated in turfgrass experiments. Color is [...]

The demand for water treatment chemicals in the United States is expected to rise at a five percent annual rate between 2000 and 2005, almost double that commonly projected for [...]

School success may depend largely on skilled administrators according to recent research on educational reform. However many practices for selection, preparation and reward of school administrators doe not always determine and develop required competence. Group process is rarely included in the preparation programs of school administrators, but group process skills allow the school administrator to concentrate on the productivity of school clients.

Traditional offerings still abound, but advances in technology have also opened up new possibilities. [ABSTRACT FROM AUTHOR]

A study of the success of alternative schools in providing an effective learning environment for at-risk high school students by analyzing the work of the OASIS educational program associated with the Cooperative Federation for Educational Experiences project revealed that alternative schools can provide quality education for at-risk pupils. Students felt that alternative school teachers were more concerned about them and less authoritarian. They also felt that they were given more opportunities for decision-making. Alternative schools also have the potential to impart life skills to students and thus promote their ability to adjust in society.

Desirable and undesirable agronomic characteristics of tall fescue (Festuca arundinacea Schreb.) have been attributed to infection by a nonpathogenic fungal endophyte (Acremonium coenophialum Morgan-Jones & Gams, section Alba-lanosa). It has been suggested that stomatal control of water loss is more closely regulated in symbiotic than nonsymbiotic tall fescue, a feature that may improve drought resistance. A greenhouse experiment was designed to study apparent photosynthesis, stomatal conductance, transpiration, and leaf water potential in two genotypes of symbiotic and nonsymbiotic tall fescue grown in polyethylene glycol solutions of -0.1, -0.3, -0.7, and -1.0 MPa water potential. Symbiotic plants of one genotype (CB1) had slightly higher photosynthesis, stomatal conductance, and transpiration at intermediate levels of water stress than nonsymbiotic plants. Gas exchange of the second genotype (DN7) may have been affected by endophyte infection, as photosynthetic rates of symbiotic plants grown at -1.0 MPa were slightly higher than nonsymbiotic plants. The increased photosynthesis and stomatal conductance in genotype CB1 were apparently the result of turgor maintenance in mature leaves of symbiotic plants. At moderate and low water potential, leaves of symbiotic plants had a greater turgor potential than nonsymbiotic plants. These data suggest that the endophyte of genotype CB1 does a more favorable turgor pressure in mature leaves, which may lead to greater photosynthesis at lower water potentials.

Past experiments on sand-based putting greens have frequently used randomized complete blocked designs (RCBD), even though these experimental areas are relatively uniform with regard to external variables. Consequently, completely randomized designs (CRD) may have had better precision with which to estimate treatment effects compared with RCBD. The objective of this study was to estimate the relative efficiency (ERE) of a RCBD compared with a CRD when evaluating common parameters on sand-based putting greens. Uniformity trials were conducted in Arkansas and Nebraska on sand-based putting greens established with creeping bentgrass (Agrostis palustris Huds.). Estimated relative efficiency values were calculated for varying blocking schemes when measuring canopy temperature, soil temperature, soil moisture, dipping yield, and macronutrient content in plant tissues. Since canopy temperatures were time dependent, when those measurements were collected by a blocking scheme, the associated RCBD was approximately nine times more efficient than a CRD. For the remaining parameter and blocking scheme combinations, ERE values indicated that the precision between RCBD and CRD was similar. Therefore, it is likely that the precision with which treatment effects are estimated is not compromised from the use of RCBD on sand-based putting green trials., WHEN DESIGNING FIELD EXPERIMENTS, blocking is often used to increase precision on treatment effects by reducing experimental error variance (Kuehl, 1994). Blocking stratifies experimental units into homogenous groups, and in [...]

`Millennium' tall fescue (Festuca arundinacea Schreb.) (Reg. no. CV-84, PI 611124) was released by Turf Merchants, Inc., Tangent, OR, in September 1998. Germplasm developed by the New Jersey Agricultural Experiment [...]

To the editor: Regarding 'The 10 Worst Corporations of 2004:' What about Microsoft? What about Sony and Walt Disney? Does it matter that they have engaged in predatory practices, but [...]