Kentucky bluegrass (Poa pratensis L.) is frequently established on sports fields that receive wear during one or more seasons. Differences exist among Kentucky bluegrass cultivars for seasonal performance characteristics such as spring green-up and summer stress tolerance. The objective of this study was to determine; whether the wear tolerance and recovery of Kentucky bluegrass cultivars were dependent on season. Twenty-two Kentucky bluegrass cultivars, representing nine genetically diverse Kentucky bluegrass types, were established in September 2002 in North Brunswick, NJ on a loam. The effects of simulated wear were evaluated during spring, summer, and fall in 2004 and 2005. Generally, Kentucky bluegrass was more tolerant of wear during spring than summer or fall and recovery was more rapid after spring wear. The performance of many cultivars depended on season of wear; however, 'Julia' consistently exhibited the greatest wear tolerance as well as recovery. Compact-Midnight Type cultivars ('Midnight', 'Midnight II', and 'Liberator') had good wear tolerance during fall wear, however were slow to recover after fall wear. 'Cabernet', 'Lakeshore', 'Moon Shadow', 'Limousine', and 'Jefferson' exhibited more rapid recovery from fall wear during the next spring. 'Langara', 'Bedazzled', and 'Touchdown' had poor wear tolerance and recovery during all seasons. The season(s) of play should be considered when selecting Kentucky bluegrass cultivars for sports fields.

Applied Turfgrass ScienceVolume 6, Issue 1 p. 1-4 Applied Turfgrass Science Brief Tolerance of Creeping Bentgrass Cultivars and Selections to Anthracnose in New Jersey S. A. Bonos, Corresponding Author S. A. Bonos bonos@aesop.rutgers.edu Plant Biology and Pathology, Rutgers University, New Brunswick, NJ, 08901Corresponding author: S. A. Bonos. bonos@aesop.rutgers.eduSearch for more papers by this authorE. N. Weibel, E. N. Weibel Plant Biology and Pathology, Rutgers University, New Brunswick, NJ, 08901Search for more papers by this authorT. J. Lawson, T. J. Lawson Plant Biology and Pathology, Rutgers University, New Brunswick, NJ, 08901Search for more papers by this authorB. B. Clarke, B. B. Clarke Plant Biology and Pathology, Rutgers University, New Brunswick, NJ, 08901Search for more papers by this author S. A. Bonos, Corresponding Author S. A. Bonos bonos@aesop.rutgers.edu Plant Biology and Pathology, Rutgers University, New Brunswick, NJ, 08901Corresponding author: S. A. Bonos. bonos@aesop.rutgers.eduSearch for more papers by this authorE. N. Weibel, E. N. Weibel Plant Biology and Pathology, Rutgers University, New Brunswick, NJ, 08901Search for more papers by this authorT. J. Lawson, T. J. Lawson Plant Biology and Pathology, Rutgers University, New Brunswick, NJ, 08901Search for more papers by this authorB. B. Clarke, B. B. Clarke Plant Biology and Pathology, Rutgers University, New Brunswick, NJ, 08901Search for more papers by this author First published: 06 August 2009 https://doi.org/10.1094/ATS-2009-0806-01-BRCitations: 1 Bonos, S. A., Weibel, E. N., Lawson, T. J., and Clarke, B. B. 2009. Tolerance of creeping bentgrass cultivars and selections to anthracnose in New Jersey. Online. Applied Turfgrass Science doi:https://doi.org/10.1094/ATS-2009-0806-01-BR. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume6, Issue12009Pages 1-4 RelatedInformation

Creeping bentgrass (Agrostis stolonifera L.) has received more study and use as golf course turf than velvet bentgrass (A. canina L.). The objective of two field trials, managed as putting green and fairway turf, was to evaluate the performance of creeping and velvet bentgrass in mixed swards with annual bluegrass (Poa annua var. reptans Hausskn.) when subjected to traffic stresses. The trials were initiated on a sandy loam (fine‐loamy, mixed, mesic Typic Hapludult). Wear (no‐wear and wear) and compaction (no‐compaction and compaction) were applied in a factorial combination to 15 creeping or velvet bentgrasses. Turf quality, turf density, and bentgrass populations of cultivars were more susceptible to wear stress than compaction. Velvet bentgrass performed and resisted the spread of annual bluegrass better than most creeping bentgrasses. Cultivars that formed denser turf performed well in both trials; ‘Vesper’, ‘7001’, and ‘Penn A‐4’ had the best overall performance. Interactions indicated ‘SR 7200’, ‘Penn G‐2’, and ‘Providence’ were susceptible to compaction. ‘Pennlinks’ and ‘Penncross’ were ineffective at maintaining desirable bentgrass populations particularly in the putting green trial. Management strategies that minimize wear damage may have a greater impact on turf quality and bentgrass populations in mixed stands than practices intended to manage compaction, particularly on well‐drained soil.

Sand-based root zones are commonly used for construction of golf course putting greens. Objectives of this field study were to (i) evaluate sand-based root zone mixtures varying in amendment (fine loam, peat, and inorganic) on the establishment of 'L-93' creeping bentgrass (Agrostis stolonifera L.), (ii) compare findings to related published studies, and (iii) repeat the trial in two locations varying in air circulation to assess microenvironmental effect. Eleven root zone mixtures, using predominantly medium-sized sand as the majority component, were replicated four times in a randomized complete block design nested within the two microenvironments. Plots were seeded in May 1998 and establishment was assessed to June 1999. Mixtures with a capillary porosity (-3 kPa water potential) at the high end of, or slightly exceeding, the United States Golf Association (USGA) criterion range (0.15-0.25 m(3) m(-3)) provided more rapid establishment and better turf performance, yet root mass was lowest in these mixtures. Thus, variation in water availability among mixtures appeared sufficient to affect distribution of dry matter between roots and shoots. Mixtures amended to provide greater nutrient retention improved turf establishment; however, low water retention in the inorganic mixtures negated this advantage longer term as irrigation and fertilization shifted from establishment toward a maintenance objective. While shoot response to microenvironment was more limited, total root mass 1 yr after seeding was 24% greater in the open microenvironment than the enclosed, indicating that the initial effect of enclosed microenvironments on growth may go unrecognized during grow-in unless rooting is assessed.

Five pre-pubertal Holstein heifers were exposed for 16 h to a light intensity of 400 lx and thereafter to intensities of 0, 50, 100, 200, or 400 lx for an additional 8 h (5 x 5 Latin square design). Exposure to all intensities inhibited (P < 0.05) melatonin secretion for the initial few hours (of the 8-h exposure period); melatonin concentration subsequently increased, particularly with the lower light intensities. Only the highest light intensity (400 lx) suppressed (P < 0.05) plasma melatonin concentrations for the entire 8-h exposure period. Key words: Threshold, supplemental, light, intensity, inhibition, melatonin, heifer

A rare, multi-phased form of slope failure is described from the Assynt area of NW Scotland. Although possessing some of the characteristics of a rock glacier, detailed analysis of the clastic deposits involved in the slope failure suggest that if is best interpreted as a complex landslide. After the downwastage of the Late Devensian ice sheet, a rockfall talus sheet developed on the southern slopes of Beinn nan Cnaimhseag. The removal of confining pressure imposed by the ice sheet, together with the presence of mylonised facies and fissuring due to tectonic movement along the Ben More thrust plane which cuts across the top of this hill, led to rock sag and collapse of the central part of the slope. Holocene rockfall talus cones have subsequently formed, and partly bury the upper slopes of the blocky apron of debris created by the landslide. Large boulders found on the upper surface of the blocky debris are due to later toppling processes from the free face below the summit of the hill.

A dated landscape history of the Allt nan Uamh valley in the Assynt area is constructed, spanning the last 300 ka, using geomorphological analysis, U-series speleothem dating, and existing cave surveys. The mean rate of valley deepening is estimated to lie between 47 and 68 m per glacial/interglacial cycle of 100 ka. This, combined with an estimated duration of glaciation, implies glacial erosion rates of about 2 mm a(-1), in agreement with modern process measurements. (C) 1997 by John Wiley & Sons, Ltd.

Synopsis The mapping of an extensive pattern of glacial striae on quartzite bedrock has enabled the reconstruction of basal flow patterns beneath the Late Devensian ice sheet. There is evidence for an earlier phase of ice movement in certain limited localities, believed to relate to ice build-up. Ice flow beneath a thick ice sheet that covered all but the highest parts of the terrain was followed by a phase in which basal flow was strongly influenced by topography. The ice sheet appears to have been warm-based throughout much of its existence.

Synopsis The distribution of glacial erratics shows that at some time in the past the Assynt area has been glaciated by an ice sheet of considerable thickness which, at the glacial maximum, probably covered all but the highest mountains. Whether this was the Late Devensian ice sheet or some earlier glacial phase cannot be determined from the evidence of glacial erratics alone. A model for the development of an ice sheet in this part of Scotland is proposed, whereby initial ice development occurred predominantly on the eastern side of the mountains, with glacial build-up continuing until the ice was thick enough to flow westwards as well as eastwards. The ice divide thus established always lay to the east of the Assynt mountains. The dispersal of erratics appears to have been limited in the ice-shed zone.

Abstract230Th/234U dates are presented for 26 speleothems from three areas in Britain: Assynt, N.W. Scotland; N.W. Yorkshire; Mendip Hills, Somerset. These dates suggest that speleothem growth was widespread but rare in the period from 40 to 26 Ka, absent from 26 to 15 Ka, and abundant from 15 Ka to the present. The absence of speleothems between 26 and 15 Ka is attributed to glaciation in Yorkshire and Assynt and, tentatively, to continuous permafrost development in the Mendip Hills. The occurrence of speleothems before 26 Ka places restrictions on the extent of any ice sheet which may have been present in Scotland, and indicates that N.W. Scotland was not subjected to continuous permafrost at that time.

Eighteen species of Candaciidae have been identified from collections made at 339 stations in the Indian Ocean. Most species are zonally distributed; however, on the eastern and western sides of the Indian Ocean, species ranges are extended north or south by boundary currents. Factor analysis was used to cluster phenotypically similar species based on 130 characters taken from the maxilla (a feeding appendage), the first swimming foot, and the fifth foot (a secondary sexual structure). Four morphological clusters were extracted. Clusterings based on separate factor analyses limited to characters from feeding or from sexually adapted appendages are in substantial agreement with the clusters based on composite morphology. Two geographically recurrent groups of species were also identified, one from equatorial waters, one from the central gyre. Each recurrent group is composed of species exceptionally different in body size and belonging to different morphological clusters. Niches of the species are compared using Hutchinson's multidimensional hypervolume as a model. An attempt is made to describe the niche of each species in terms of environmental variables measured at stations where the species was abundant. Environmental variables (dimensions) included in this study are space, time, temperature, food, oxygen and salinity. Mean niche adaptations of most of the species are separable from congeners along at least one niche dimension. It is proposed that community relationships among the Candaciidae developed to prevent both gamete loss and to avoid trophic competition. It is postulated that newly evolving species underwent contemporaneous displacement of both secondary sexual and trophic characters as a condition for sympatry, or diverged in their physiological adaptations to escape sympatric interference.

This project is designed to i) improve rec- ommendations for sand particle size distribution and the depth of the root zone by consideration of the microenvironment; ii) evaluate composts as organic additives and inorganic products for root zone mixes compared to peat sources; iii) assess the potential of various root zone mixes to reduce management and resource inputs; and iv) monitor the physical, chemical, and biologi- cal changes that occur in root zones as greens mature for understanding factors that contrib- ute to the success or failure of greens.