bluuebunny/crossref_metadata_2025 huggingface dataset:
Classification of Zoysiagrass Genotypes on Rooting Capacity and Associated Performance during Drought
Authors: Christensen Christian T. , Zhang Jing , Kenworthy Kevin E. , Erickson John , Kruse Jason , Schwartz Brian
Published: October 2017

Characterization of rooting capacity in the greenhouse is a routine screening procedure for assessing a plant's ability to cope with drought stress. However, an association between rooting capacity in the greenhouse and turf performance in the field during drought is not always found. The objectives of the study were (i) to classify zoysiagrass (Zoysia spp.) rooting characteristics under well‐watered conditions in the greenhouse, (ii) to compare zoysiagrass performance under drought conditions in the field, and (iii) to relate the results from the greenhouse to the drought responses in the field. The greenhouse study included 17 zoysiagrass genotypes grown in clear acrylic tubes. Root morphological traits and dry weight at different depths (0–30, 30–60, 60–90, and 90–120 cm) were evaluated. Visual responses of zoysiagrass to field dry down were evaluated, and total turf performance index (TTPI) was used to rank the genotypes. Genotypes with higher root length density and root dry weight at 30 to 120 cm, deeper maximum root depth, and lower fraction of surface root length in the greenhouse study were better performers (high TTPI) in the field dry down study and included ‘UF 182’, ‘Emerald’, ‘JaMur’, and ‘Palisades’. The correlation between the greenhouse study and the field dry down study suggests that improvement of drought resistance may be achieved by screening for root traits in the greenhouse.
Dissipation of Foliar Bifenthrin Residues after Application to a Tall Fescue Lawn and Implications for Human Exposure
Authors: Cooper R. J. , Peacock C. H. , Shea D. , Miller G. H. , Gannon T. W. , John C. V.
Published: October 2017

Dislodgeable foliar residues (DFR) can be a primary route for human exposure after pesticide application to turfgrass areas. Consequently, a significant portion of applied pesticide may be available for human exposure via dislodgeable residues. In this study, DFR were determined over a 15‐d period after 6 Oct. 2006 application of the insecticide bifenthrin {2‐methylbiphenyl‐3‐ylmethyl (1RS,3RS)‐3‐[(Z)‐2‐chloro‐3,3,3‐trifluoroprop‐1‐enyl]‐2,2‐dimethylcyclopropanecarboxylate} to a mature stand of ‘Confederate’ tall fescue (Festuca arundinacea Schreb). Foliar residues were determined by wiping treated turfgrass with a distilled‐water‐dampened cheesecloth and analyzing samples using gas chromatography–mass spectrometry. Approximately 35% of the total applied bifenthrin (213,000 ng dm−2) was available to be dislodged over 15 d with 34% DFR loss occurring immediately after application. Residue loss measured 3 and 8 h after treatment contributed an additional 0.5% of the total applied bifenthrin dislodged from the foliar surface. Maximum bifenthrin DFR detected immediately after application resulted in a maximum estimated hazard quotient of 1.1 × 103 for the 15‐d study, indicating possible human toxicological implications. Residue levels detected 2, 5, 7, 11 and 15 d after application measured <1% of total applied bifenthrin, indicating minimal human health risk when applied at the labeled rate.
The Effect of Ice Encasement and Protective Covers on the Winter Survival of Six Turfgrass Species on Putting Greens
Authors: Waalen Wendy M. , Espevig Tatsiana , Kvalbein Agnar , Aamlid Trygve S.
Published: October 2017

Ice encasement (IE) is the most economically important winter stress in Scandinavia; however, little is known about the IE tolerance of different turfgrass species and subspecies except that creeping bentgrass (Agrostis stolonifera L.) is more tolerant than annual bluegrass (Poa annua L.). The objective of this study was to assess the impact of IE and two protective covers (plastic and plastic over a 10‐mm woven mat) on the winter survival of six cool‐season turfgrasses commonly used on golf greens. The experiment was conducted on a sand‐based green at Apelsvoll, Norway (60°42′ N, 10°51′ E) during the winters of 2011–2012 and 2012–2013. Turfgrass samples (8 cm in diameter, 10 cm deep) were removed from the plots at the time of cover installation and throughout the winter. The samples were potted and percent live turfgrass cover assessed after 21 d of regrowth in a growth chamber. Percent turfgrass cover, percent disease, and turfgrass quality were also registered in the field plots in spring. Results indicated that velvet bentgrass (Agrostis canina L.) had superior tolerance to IE, surviving for 98 and 119 d of IE during the winters of 2011–2012 and 2012–2013, respectively. The order of IE tolerance in 2012–2013 was: velvet bentgrass > creeping bentgrass > Chewing's fescue (Festuca. rubra L. ssp. commutata), slender creeping red fescue (F. rubra L. ssp. litoralis) ≥ colonial bentgrass (A. capillaris) > annual bluegrass. Colonial bentgrass responded negatively to both protective covers in 2012 due to the development of Microdocium nivale. None of the species benefited from the plastic cover alone, compared with natural snow conditions. Annual bluegrass was the only species that benefited from plastic over a woven mat.
Genetic Diversity of Greens‐type Bermudagrass Genotypes as Assessed with Simple Sequence Repeat Markers
Authors: Fang Tilin , Wu Yanqi , Moss Justin Q. , Walker Nathan R. , Martin Dennis L.
Published: October 2017

Fine‐textured, ultradwarf interspecific triploid (2n = 3x = 27) bermudagrass cultivars [Cynodon transvaalensis (2n = 2x = 18) × C. dactylon var. dactylon (2n = 4x = 36)] have been the turfgrass industry standards for golf putting greens in the southeast, southwest, and transition regions of the United States. Winterkill is one of the major challenges when ultradwarf bermudagrasses are used in the transition zone. Narrow genetic diversity among the ultradwarf bermudagrass cultivars is considered a likely and important reason for their susceptibility to prevalent diseases. This research was conducted to characterize genetic diversity among greens‐type experimental bermudagrass genotypes as compared with ultradwarf cultivars assessed with simple sequence repeat (SSR) markers. Fifteen elite Oklahoma State University (OSU) experimental bermudagrass genotypes and four commercial standards (Champion Dwarf, Mini Verde, TifEagle, and Tifdwarf) were genotyped with 45 SSR markers selected from a recently developed bermudagrass genetic linkage map in our laboratory. In the cluster analysis, the four commercial cultivars formed one group with a genetic similarity coefficient of 1.00, whereas the similarity coefficients among the experimental selections ranged from 0.64 to 0.93. The percentage of polymorphic bands was increased by 98.31%, and the Nei's genetic diversity increased from 0 to 0.3329. These results indicated that the OSU experimental genotypes increased genetic diversity over the commercial bermudagrass standards as expected and that they could be released as new greens‐type turf bermudagrass cultivars if they can withstand field testing.
Annual Bluegrass Control during Hybrid Bluegrass Establishment from Sprigs
Authors: Yu Jialin , McCullough Patrick
Published: October 2017

Hybrid bluegrass (Poa arachnifera Torr. × P. pratensis L.) establishment may be compromised by the emergence of annual bluegrass (P. annua L.) in the fall. The objective of this research was to evaluate the efficacy of herbicides for annual bluegrass control during the establishment of ‘DALBG 1201’ hybrid bluegrass from sprigs. Herbicides were applied at two timings: 5 d after planting (DAP) or 3 wk after planting (WAP). Hybrid bluegrass cover was rated four times between 9 and 35 WAP. The first and second visual ratings of annual bluegrass cover were made between 16 and 18 and at 30 WAP, respectively. At 26 WAP, hybrid bluegrass cover was approximately two‐fold in plots treated with mesotrione, oxadiazon, or topramezone compared with the nontreated. Primisulfuron applied singly or sequentially at 0.04 kg ha−1 controlled annual bluegrass ≥88% but reduced hybrid bluegrass cover >30% relative to the nontreated. Ethofumesate applied at 0.84 kg ha−1 at 3 WAP controlled annual bluegrass 74%. Oxadiazon at 1.12 or 2.24 kg ha−1 applied 5 DAP controlled annual bluegrass 67 to 75% at 30 WAP without reducing hybrid bluegrass cover. All other treatments provided poor (<70%) control of annual bluegrass. Overall, hybrid bluegrass was tolerant to ethofumesate, oxadiazon, mesotrione, and topramezone at rates evaluated during establishment from sprigs. Programs that included ethofumesate at 0.84 kg a.i. ha−1 or oxadiazon at 1.12 or 2.24 kg ha−1 provided best annual bluegrass control and improved hybrid bluegrass cover from the nontreated.
Drainage Behavior of Sports Pitches–A Case Study Review
Authors: Fleming P.R. , Frost M.W. , Simpson M. , Everett R. , Gibbs R.J.
Published: October 2017

The drainage behavior of sports pitches has traditionally been designed from experience with hydraulic performance rarely measured in detail. Within the wider industry and regulatory bodies there is a perception that storm water and increased drainage rates from sports pitches contribute to local flood risk. Empirical observations have suggested that in reality pitch drainage systems may discharge water at low volumes and rates and there is often limited surface run‐off. Furthermore it appears that lack of technical guidance on the discharge of water from sport pitch drainage systems may have led to misunderstanding their drainage behavior and possible benefits they could bring to water management as opposed to perceived dis‐benefits. This paper summarizes selected results of a case study which included field measurements of weather and discharge behavior on a range of natural turf sports pitches in England. The findings from this study indicate that natural turf sports pitches can provide resistance to flow and hence advantageous attenuation of rainfall and storm water. Additionally sports pitches can store large volumes of water within the pervious materials used in their design. The study has confirmed that sport pitches demonstrate the key functions that are reflected in the design requirements of Sustainable Urban Drainage Systems (SuDs) such as pervious pavements providing source control of surface rain water.
Comparisons of Turf‐Type Bahiagrass (Paspalum notatum Flügge) Lines for Root and Shoot Traits under Various Nitrogen Regimes
Authors: Pereira Mateus C. , Rios Esteban F. , Kenworthy Kevin E. , Quesenberry Kenneth H. , Blount Ann , Erickson John , Altpeter Fredy , Munoz Patricio
Published: October 2017

Water and fertilizer regulations in Florida have created a market for low‐maintenance grasses. The objectives of this study were to compare rooting and turf performance of three selected turf‐type bahiagrass lines (‘M36’, ‘WEMS12’, and ‘FLDW51’), in comparison with ‘Wilmington’ and ‘Argentine’ bahiagrass, and ‘Floratam’ St. Augustinegrass, grown under three nitrogen (N) rates (49, 98, and 196 kg N ha−1). The experiment was conducted during the summer and fall 2014 in a greenhouse located at the Genetics and Physiology Agronomy Unit, University of Florida, Gainesville, FL, and arranged as a randomized complete block design with four replications. Positive correlations were found between biomass and rooting traits, and both were negatively correlated with shoot and root crude protein. Coarse leaf texture was positively correlated with higher biomass yield but was negatively correlated with crude protein, number of nodes, and chlorophyll content. Cluster analysis based on principal component analysis 1 (51% explained variance) indicated two genotype groupings. Wilmington, WEMS12, and FLDW51 were grouped closely to crude protein, number of nodes, and chlorophyll content, whereas Floratam, Argentine, and M36 were grouped near leaf texture, biomass, and rooting traits. Principal component analysis 2 (18% explained variance) indicated that M36 and Wilmington were grouped closely to leaf length, rhizome size, root to shoot biomass, and crude protein ratios. The three experimental lines and Wilmington exhibited darker green color, had better color retention, and had more nodes per rhizome, and WEMS12 and FLDW51 had narrower leaves. Higher N rates induced higher chlorophyll content and crude protein. Floratam, Argentine, and M36 produced higher biomass yields and exhibited more vigorous root parameters. The improved turf attributes exhibited by these selected lines should be further evaluated for persistence under limited input field regimes.
Response of Seashore Paspalum Genotypes to Two Isolates of Sclerotinia homoeocarpa
Authors: Benda Nicole D. , Flor Norma C. , Harmon Phillip F. , Kenworthy Kevin E.
Published: October 2017

Seashore paspalum (Paspalum vaginatum Schwartz) is a warm‐season turfgrass noted for its salt tolerance and is used on golf course fairways and greens. Dollar spot (Sclerotinia homoeocarpa F.T. Benn.) is an important disease of seashore paspalum, causing distinct silver dollar‐sized necrotic patches to form on the turf. Previous research by Flor et al. (2013) identified host plant resistance as a potential tool for dollar spot disease management using a single dollar spot isolate, UF0421. However, another isolate appeared more virulent in follow‐up experiments. With the intent of developing stronger selection pressure, disease response to these two characterized S. homoeocarpa isolates was compared in the current study under controlled environmental conditions using nine experimental lines of seashore paspalum and two commercial cultivars (‘SeaDwarf’ and ‘Sea Isle Supreme’) as controls. The second, putatively more virulent isolate consistently caused more damage to all 11 paspalum genotypes. An isolate × genotype interaction was not observed. Plant genotypes differed significantly in disease response, and all genotypes but one were consistent with the previous study. We successfully identified a more virulent strain of dollar spot. Using a more virulent strain will provide stronger selection pressure for development of resistance to dollar spot, allowing for clearer identification of resistant genotypes.
Effects of De‐Icing Products on Putting Green Turf
Authors: Hollman A. B. , Heineck G. C. , Frank K. W. , Bauer S. J. , Bryan J. , Horgan B. P.
Published: October 2017

Prolonged ice cover of putting greens can lead to turfgrass crown death. De‐icing products can aid in ice removal, but variations in ice thickness and putting green topography increase the likelihood these products will contact and damage ice‐free turfgrass areas. The objective of this research was to assess, in two separate trials, the phytotoxic effect of chemical de‐icers and the greening effect of solar de‐icers applied directly to ice‐free creeping bentgrass (Agrostis stolonifera L.) native soil and sand‐based putting greens. The chemical de‐icing trial included 11 products applied at rates of 136.3 and 68.2 g m−2 for all chemicals with the exception of sodium acetate, for which the label dictated rates of 136.3, 97.6, 73.2, 48.8, and 24.4 g m−2 were applied. The solar de‐icing trial contained nine products applied at a dry volume of 0.3 L m−2 to account for differences in bulk density. In 2014, only urea‐based de‐icing chemicals were damaging to the turf. In 2015, damage was seen by all de‐icing chemicals with urea‐based chemicals having the most severe damage; warm temperatures and thawed soil likely led to actively growing tissue encountering de‐icing chemicals and increasing the severity of the damage. Organic‐based fertilizers, categorized as solar de‐icing products, produced the greatest increase in green color in both years of the trial. Proper selection of chemical and solar de‐icing products, along with application timing, can limit damage to ice‐free bentgrass greens.
Response of Tall Fescue and Kentucky Bluegrass Mixtures to Wear
Authors: Park Bradley S. , Samaranayake Hiranthi , Murphy James A.
Published: October 2017

Tall fescue (TF) [Schedonorus arundinaceus (Schreb.) Dumort.] and Kentucky bluegrass (KBG) Poa pratensis L.) are often seeded as mixtures in temperate and transition climates. This study assessed the performance and species composition of TF and KBG mixtures containing newer cultivars that were subjected to wear. Individual plots of TF cultivars were established in 2010 on a loam along with 16 mixtures of TF and KBG (TF 90/KBG 10; w/w). Wear was applied during autumn 2011, 2012, and 2013. Plots were evaluated for turfgrass quality, brown patch disease (caused by Rhizoctonia solani), and species composition. Data were analyzed using a 5 × 4 × 2 factorial of KBG (none, ‘Midnight II’, ‘Blue Note’, A05–361, A05–361), TF (‘Falcon V’, ‘Mustang 4’, ‘Justice’, ‘Greenkeeper’), and wear (no wear and wear) arranged in a strip plot design with three replications. Wear reduced quality but had no effect on species composition. Mixing KBG with Falcon V or Mustang 4 TF had no effect on quality after wear compared with either TF alone; however, the quality of Greenkeeper TF was better when mixed with Midnight II or Blue Note KBG, whereas mixing with A05–361 and A05–344 KBG had no effect on quality. Kentucky bluegrass selection had a much greater influence on species composition compared with TF selection. Tall fescue composition was influenced by KBG cultivar and ranged from 37 to 79%. Brown patch severity was decreased in TF mixtures with KBG and was more strongly influenced by KBG cultivar than TF cultivar. Our data indicate that KBG cultivars can dramatically affect TF composition of mixes and brown patch severity, whereas autumn wear does not.
Spatial and Temporal Distribution of Phyllophaga spp. Infesting Bermudagrass Stands in Oklahoma
Authors: Graf N. , Rebek E. , Royer T. , Walker N.
Published: October 2017

Larvae of Phyllophaga spp. (Coleoptera: Scarabaeidae) are important direct and indirect turfgrass pests in the southern United States. Confirming the presence of these larvae is an important integrated pest management practice in turf production systems and determines the need for treatment. However, several different species (e.g., P. crinita, P. submucida, and P. crassissima) are known to occur within the same turfgrass stand, and each species has a different oviposition period. The objective of this study was to determine the spatial and temporal distribution of Phyllophaga spp. in intensely managed bermudagrass. During spring through summer of 2009, larvae were collected after harvesting bermudagrass turf from two sod farms in Oklahoma. The location of each grub was determined using global positioning system tracking. Identification of larvae was based on polymerase chain reaction amplification and sequencing of the cytochrome c oxidase I gene. Species spatial and temporal distribution patterns were analyzed by detrended correspondence analysis using CANOCO 5.04. Seven species of Phyllophaga were collected, and each study site contained at least one species that was not found at the other. Detrended correspondence analysis resulted in low β diversity values. Beta diversity reflects how far apart species are in the gradient of species composition. The low β diversity scores obtained in this study show that different species of Phyllophaga were present in no recognizable pattern of temporal or spatial distribution.
Isolation of a Potential Antifungal Protein Produced by Epichloë festucae, a Fungal Endophyte of Strong Creeping Red Fescue
Authors: Tian Zipeng , Wang Ruying , Ambrose Karen V. , Clarke Bruce B. , Belanger Faith C.
Published: October 2017

Festuca rubra L. subsp. rubra (strong creeping red fescue) exhibits endophyte‐mediated fungal disease resistance. Epichloë festucae Leuchtm., Schardl & M.R. Siegel, the fungal endophyte of F. rubra subsp. rubra, produces an abundant transcript encoding a potential secreted antifungal protein. The objective of this work was to confirm the presence of the antifungal protein in the apoplastic proteins and to express it in the yeast Pichia pastoris for future tests for activity against turfgrass fungal pathogens.
Flat Mites: A Potential Threat to Turfgrasses Worldwide, or Already Widespread?
Authors: Seeman Owen D. , Akamine Hikaru , Loch Donald S.
Published: October 2017

Two species of flat mites (Acari: Tenuipalpidae) from the genus Dolichotetranychus have recently been found to cause significant damage to Cynodon (bermudagrass) and Zoysia spp. turfgrasses. Despite records of D. australianus infesting bermudagrass throughout Africa, the Middle East, and Australia for more than 70 yr, most turf managers assume that any apparent mite damage is due to the widely publicized eriophyoid bermudagrass mite, Aceria cynodoniensis, rather than validating this under the microscope. To an experienced eye, the visual symptoms are distinctly different from those typically associated with A. cynodoniensis; but they are similar to the symptoms seen with the zoysiagrass mite, D. zoysiae, in Okinawa (Japan). The possibility that there may be further undescribed or misidentified Dolichotetranychus species affecting turfgrasses is discussed, together with examples and biosecurity implications. One such species that may prove to be more significant than hitherto suspected, if routine microscopic diagnosis were to be implemented, is D. summersi, which has been recorded five times from bermudagrass in the United States during the 1950s and 1960s but without any indication of the symptoms caused. The importance of making microscopic examinations of suspected mite infestations is emphasized.
Winter Injury of Fine‐Textured Interspecific Zoysia Hybrids in the Upper Transition Zone of the USA
Authors: Fry Jack , Chandra Ambika , Genovesi Dennis , Morris Kevin , Xiang Mingying
Published: October 2017

Fine‐textured, high‐quality zoysiagrasses (Zoysia spp.) lack freezing tolerance for use in much of the transition zone of the United States. Two fine‐textured interspecific zoysiagrass hybrids, KSUZ 0802 [Z. matrella (L.) Merr. × Z. japonica Steud.] and KSUZ 1201 [Z. japonica × Z. pacifica (Goudswaard) M. Hotta & Kuroki × Z. japonica] were evaluated in the field for winter survival in Manhattan, KS, along with standards ‘Meyer’ (Z. japonica), ‘Empire’ (Z. japonica), and ‘Zeon’ (Z. matrella). Grasses were established in the field from vegetative plugs in June 2013 and evaluated for winter injury and quality from 2014 to 2016. The low temperatures during the winters each year were −24 (14 Jan. 2014), −19 (7 Jan. 2015), and −18°C (10 Jan. 2016), respectively. The greatest winter injury occurred in 2014 and 2015. When plots were rated in the spring, Meyer, KSUZ 0802, and KSUZ 1201 had <10% winter injury in each year, whereas Empire and Zeon exhibited >20% injury in 2014 and >90% injury in 2015. Both KSUZ 0802 and KSUZ 1201 had quality that was better than Meyer on 6 of 13 rating dates. KSUZ 0802 and KSUZ 1201 are high‐quality, fine‐textured, cold‐hardy genotypes that are well suited for use in the transition zone.
Winter Injuries on Golf Greens in the Nordic Countries: Survey of Causes and Economic Consequences
Authors: Kvalbein Agnar , Waalen Wendy Marie , Bjørnstad Lise , Aamlid Trygve Sveen , Espevig Tatsiana
Published: October 2017

There has long been a claim that winter injuries of grass are a significant economic burden for golf courses in the Nordic countries. To confirm this claim, in 2015 the Norwegian Institute of Bioeconomy Research and the Norwegian Golf Federation, with support of the Scandinavian Turfgrass and Environment Research Foundation, conducted a net‐based survey about winter injury in the five Nordic countries (Denmark, Finland, Iceland, Norway, and Sweden). This comprehensive survey showed that total costs of repair of winter‐injured greens and fairways together with lost revenue on golf courses in the Nordic countries can be at least €14 million. In a year with significant winter injuries, the average cost to repair the turf was between €3000 and €12,000 on 88% of the courses. The revenue loss after a winter with considerable injuries was less than €6000 at 50% of the courses, and 25% of the courses reported a loss between €6000 and €12,000 for these years. The causes of winter injuries varied depending on geography and grass species used on the greens. Biotic factors played a major role in the southern part of Scandinavia, and ice and water injuries were most devastating north of 60°N. This paper summarizes some of the answers from the respondents, including information about the dominating grass species on Nordic golf greens.
Water Restriction Impact on Surface Hardness and Soil Volumetric Water Content on Recreational Sports Fields
Authors: Chang Kuo‐Hsien , Powers Jacqueline E. , Lyons Eric
Published: October 2017

Water‐use restrictions during the summer of 2016 in Guelph, ON, Canada, prevented the irrigation of natural turf soccer fields and provided a unique opportunity to study the effects on soil volumetric water content and surface hardness on actively used youth soccer fields. Soil volumetric water content and surface hardness were tested on a weekly basis from July through September 2016. Areas of the turf that became brown were compared with the areas that remained green. Surface hardness within areas of brown turfgrass cover frequently exceeded 100g (level of concern for player safety) even though soil volumetric water content was similar between the areas of green and brown turfgrass cover. Therefore, irrigation of sports fields during times of drought is recommended to preserve the cushioning effect of green turfgrass cover.
Annual Bluegrass Herbicide Resistance Caused by ALS Gene Mutation in Korea
Authors: Tae Hyun‐Sook , Kim Kyung‐Duck , Hong Beom‐Seok
Published: October 2017

Acetolactate synthase (ALS)‐inhibiting herbicide is widely used for control of annual bluegrass (Poa annua L.) infestation in zoysiagrass (Zoysia spp.) fairways. Field experiments were conducted 2015 and 2016 to investigate ALS herbicide resistance of annual bluegrass at the Ansung Benest Golf Club in Korea, where application of trifloxysulfuron (0.008 g m−2) resulted in poor control for 2 yr. Control of annual bluegrass was significantly less (<34%) in flazasulfuron, foramsulfuron, and trifloxysulfuron treatments than in asulam treatment (83%). In dose‐response experiments, the resistant annual bluegrass survived (>80%) 40 d after treatment in flazasulfuron, foramsulfuron, and trifloxysulfuron treatments, which were applied 10 times at labeled rates. DNA sequencing results indicated that the resistance of annual bluegrass was associated with the tryptophan to leucine target‐site mutation at ALS codon position 574. These results confirm the risk of annual bluegrass herbicide resistance at golf courses in Korea and the need for new effective herbicides that may be useful in delaying or avoiding herbicide resistance.
Evaluation of the Occurrence of Turfgrasses and Weeds after Repeated Overseeding on Fairways
Authors: Dahl Jensen Anne Mette , Bühler Oliver , Kvalbein Agnar , Aamlid Trygve S.
Published: October 2017

Research concerning the cultural practice of golf course fairways is important because legislation on pesticide reduction in Europe and North America may potentially cause serious weed problems. Establishing a strong, competitive turfgrass sward may aid in reducing the invasion of broadleaved weeds and Poa annua L. The objective of this research was to determine changes in the grass species composition and weed occurrence of in‐use fairway turfs after repeated overseeding of three grass species separately: Lolium perenne L., Festuca rubra L., and Poa pratensis L., all at rates 300 kg ha−1. Overseeding was conducted with a disc seeder, alone or in combination with extra fertilizer (50 kg N + 34 kg P ha−1) in either May or September on three Danish golf courses from 2011 to 2013. Results showed no increase in the population of F. rubra or P. pratensis after 3 yr of overseeding. Lolium perenne was successfully introduced when seeded in autumn and when extra fertilizer was added immediately after overseeding. None of the overseeding treatments reduced the occurrence of P. annua, Taraxacum officinale F.H. Wigg., Bellis perennis L., or Trifolium repens L. The results are discussed in relation to the fact that the fairways were unirrigated and that they were open to play after overseeding.
The Effect of Fraze Mowing on Overseed Establishment in Cynodon dactylon Turf
Authors: Munshaw G. C. , Dickson K. H. , Cropper K. L. , Sorochan J. C.
Published: October 2017

Cynodon spp. (bermudagrass) golf courses and athletic fields in warm‐humid and warm‐arid regions are often annually overseeded with a cool‐season grass to improve turf performance during autumn and winter. Previous research has shown that preplant cultivation treatments to the C. dactylon base typically results in improved overseed establishment. Fraze mowing is a relatively new turf maintenance technique in which thatch and grass verdure is aggressively removed by blades attached to a revolving rotor. Because fraze mowers can significantly reduce C. dactylon competition for the overseed, a study was devised to determine the effectiveness of fraze mowing as a preplant technique prior to overseeding. The study was conducted in Lexington, KY, and Knoxville, TN, during the fall and winter of 2015–2016. Treatments were applied on 17 September and consisted of an untreated control, vertical mowing (one direction, 7.5 mm deep, 2.5‐cm spacing), and fraze mowing at 0.6‐, 1.2‐, and 2.5‐cm depths. Response variables included percentage cover, germination rating, surface hardness, and percentage cover the following spring and summer. Results showed no differences between preplant treatments for germination and percentage cover the following year. However, the fraze mowing treatments resulted in reduced percentage cover for 2 to 3 wk after treatment (WAT) compared with vertical mowing and the untreated control. By 3 WAT, the overseed had established and all plots had >90% cover. Surface hardness was only slightly affected by preplant treatment at just one location, and results were not consistent.
Chemical Control of Sorghum halepense in Home Lawns across Two Different Mowing Heights
Authors: Cropper Kenneth L. , Munshaw Gregg C. , Beasley Jeffrey S. , Barrett Michael
Published: October 2017

Sorghum halepense (L.) Pers. (johnsongrass) is a common perennial grassy weed found throughout the southern United States. While not considered a common weed in home lawns, S. halepense encroachment does occur in newly constructed neighborhoods developed on old pasture lands. Limited published research regarding S. halepense control in home lawns is available even though several herbicides are labeled for S. halepense suppression or control. Therefore, experiments were conducted to examine different combinations of application rates and/or frequencies of fenoxaprop, fluazifop, and topramezone for S. halepense control in tall fescue swards. In addition to examining herbicidal control of S. halepense, weekly mowing heights of 2.5 or 8.9 cm were applied. Fenoxaprop applied at 0.10 kg a.i. ha−1 for two or three sequential applications or fluazifop at 0.10 kg a.i. ha−1 resulted in the greatest S. halepense control. A single application of fenoxaprop and all application rates and frequencies of topramezone did not reduce S. halepense compared with controls. Mowing height had no significant effect on S. halepense control.
Growing Sand‐Based Sod Using Transported Sand over Native Soil
Authors: Stewart Barry R. , Vanderford John , Wells D. Wayne , Philley H. Wayne
Published: October 2017

Turfgrass establishment on sand‐based rootzones is routinely accomplished using sod produced on a fine‐textured native soil. As a result, soil layering occurs, potentially causing initial reduction in water infiltration, rooting, aeration, playability, and overall turfgrass quality. This research was aimed at determining the feasibility of applying sand over existing native soil to produce hybrid bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt‐Davy] sand‐based sod. Treatments were a control (no sand applied), 25 mm of sand applied in eight weekly topdressing events, 25 mm of sand applied in eight weekly topdressing events plus aerification, 25 mm sand applied all at once, and 50 mm of sand applied all at once. Pre‐harvest factors evaluated were visual quality and scalping. Treatments were harvested and transplanted to a sand‐based rootzone where handleability, tensile strength, and infiltration were also evaluated. Results indicate that 25 mm of sand applied by topdressing plus aerification treatments showed higher quality pre‐harvest. The control and 25‐mm treatments were best in terms of harvesting, handleability, and sod tensile strength. Infiltration data indicated no significant differences between treatments. These outcomes, along with further analysis, could provide sod producers with a valuable product for use on sand‐based rootzones.
Occurrence, Distribution, and Introduction of Zoysia spp. and their Management and Current Use in Australia
Authors: McMaugh Peter E. , Loch Donald S. , Harrison Peter G.
Published: October 2017

Zoysia spp. are native to Australia as part of the wider distribution of the genus around the western Pacific Rim. Three taxa—two subspecies of Z. macrantha Desv. and tropical material provisionally attributed to Z. matrella (L.) Merr.—are distributed naturally along the eastern and southern coasts, mostly in littoral or near‐coastal situations. Zoysia matrella of the Asian type is found on distant offshore island territories in the Indian Ocean but has not been confirmed as native to mainland Australia. Taxonomic and agronomic studies of the native Zoysia germplasm are ongoing. Introductions of exotic Zoysia spp. have been made progressively since about the late 1950s, sometimes as seed, but mostly as vegetatively propagated accessions. Nevertheless, Zoysia spp. remain minor warm‐season turfgrasses in Australia, mainly grown in subtropical and tropical areas. In addition to at least six nonproprietary varieties, there are 18 zoysiagrass cultivars either registered or undergoing registration for Plant Breeder's Rights in Australia. Interest in the native Zoysia germplasm is increasing, in part because of the local marketability of their native origin and evidence of superior drought and cold tolerance in some clones. This interest has led to the recent development of four cultivars from Z. macrantha.
Ecological Implications of Zoysia Species, Distribution, and Adaptation for Management and Use of Zoysiagrasses
Authors: Loch Donald S. , Ebina Masumi , Choi Joon Soo , Han Liebao
Published: October 2017

The genus Zoysia Willd. comprises ±10 recognized species indigenous to the western Pacific Rim and Indian Ocean, which are collectively called “zoysiagrasses.” Three species—Z. japonica Steud., Z. matrella (L.) Merr., and Z. pacifica (Goudswaard) M. Hotta & Kuroki (previously referred to as Z. tenuifolia)—plus interspecific hybrids have a long history of use as warm‐season perennial turf and ornamental grasses in many countries. Recently, cultivars from two other species, Z. macrantha Desv. and Z. sinica Hance, have also been developed. Breeders are currently exploring the potential to incorporate attributes from these and other Zoysia species into future zoysiagrass cultivars through hybridization. The attributes of Zoysia turfgrass cultivars—their strengths and limitations—can be related back to the species and germplasm from which they have been derived, and which (together with growth and development characteristics unique to the zoysiagrasses) ultimately determine their adaptation, use, and management. Differences in temperature, shade, drought, salinity, and traffic tolerance, as well as differences in nutritional and mowing requirements among zoysiagrasses, plus comparisons with Cynodon spp. turfgrasses, are highlighted.
Distribution, Field Recognition and Implications of Phytophagous Mite Species on Cynodon spp. (Bermudagrass) and Pennisetum clandestinum (Kikuyugrass) in Australia
Authors: Loch Donald S. , Seeman Owen D. , Knihinicki Danuta K. , McMaugh Peter E.
Published: October 2017

In Australia, infestations of warm‐season turfgrasses by phytophagous mites have been known for >80 yr, but the identities of the mite species involved have remained unresolved. The long‐held underlying assumption among turf managers was that mites of the family Eriophyidae are responsible for the distorted growths frequently seen on Cynodon spp. (bermudagrasses) and Pennisetum clandestinum Hochst. ex Chiov. (kikuyugrass). A national survey during the July 2010 to June 2011 growing season followed by further sampling over the next 6 yr revealed the presence of two eriophyoid mites: Aceria cynodoniensis Sayed, the bermudagrass mite found in the United States and other countries worldwide, and Abacarus cynodonis Abou‐Awad & Nasr, a species not previously recorded outside of the Middle East. The tenuipalpid species Dolichotetranychus australianus (Womersley) was also confirmed as a substantial contributor to mite damage symptoms seen on Cynodon dactylon (L.) Pers. and C. dactylon × C. transvaalensis Burtt Davey. A newly described tarsonemid species, Steneotarsonemus hippodromus Seeman et al., was found extensively in both turf and pasture plantings of P. clandestinum. Additionally, grass‐webbing spider mites Oligonychus araneum Davis and Oligonychus digitatus Davis (Tetranychidae) also occasionally affect these and a wide range of other warm‐season grasses nonselectively in Australia. This paper describes the field and laboratory sampling procedures used to identify the various mites, document their associated field symptoms for diagnostic purposes, and determine their distribution within Australia. We also discuss the putative origin of each mite species, their international distribution (including some related species), and implications for warm‐season turf producers and facility managers, both in Australia and worldwide.
Effect of Rolling on the Lateral Spread of Khakiweed (Alternanthera pungens Kunth)
Authors: Hephner Andrew J. , Cooper Tyler , Beck Leslie L. , Henry Gerald M.
Published: October 2017

The dark green color and abundant seed production of khakiweed (Alternanthera pungens Kunth) interfere with playability and aesthetic quality of home lawns, golf courses, and athletic fields. In 2009 and 2010, the effect of rolling on lateral spread of khakiweed was investigated in Lubbock, TX. Rolling treatments were conducted using a ride‐on roller that applied a static pressure of 58 kPa at a speed of 1.55 m s−1. Weekly rolling treatments were: nonrolled, low (4 passes × 3 events), moderate (8 passes × 3 events), and high (12 passes × 3 events). Khakiweed lateral plant diameters were recorded at trial initiation and every 2 wk over 12 wk. Statistical differences in khakiweed diameters were not observed until 10 wk after initial treatment (WAIT). Nonrolled plots exhibited 30.1 cm plant diameter, similar to low rolling (24.4 cm) but greater than moderate (23.3 cm) and high (20.4 cm) rolling 10 WAIT. A decrease in plant diameter was observed in response to high rolling (19.9 cm) 12 WAIT compared with nonrolled plots (28.8 cm). Although numerically less than the nonrolled check (28.8 cm), khakiweed plant diameters in response to low (23.5 cm) and moderate (23.1 cm) rolling were statistically similar. Although rolling treatments reduced khakiweed diameter compared with the nonrolled check, plants increased in size from initial trial diameters while hybrid bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt‐Davy] cover decreased over time in response to high rolling. Therefore, practices that reduce soil compaction may be important to increase bermudagrass competition with khakiweed.
Creating Spatial Synergies around Food in Cities
Authors: Koopmans Marlinde E. , Mettepenningen Evy , Kunda Ilona , Keech Daniel , Tisenkopfs Talis
Published: October 2017

This paper focuses on the phenomenon of multifunctional urban food initiatives (MUFIs) and how, using food as a vehicle, they provide integrative solutions for a number of social, environmental and economic problems in European cities. Through an in‐depth investigation of three MUFIs in the UK, Latvia, and Belgium, the paper aims to increase understanding on how different activities are combined within MUFIs, leading to the creation and strengthening of synergies: both internal, between the different activities performed within MUFIs, and external synergies between the MUFI and the (peri‐)urban environment in which it operates. The three cases illustrate that the dense and complex urban environment in which they are situated provides possibilities to create a wide, diverse network around food, leading to a high potential for synergies to occur. In this way, MUFIs can respond to specific urban needs, which are not addressed by the state, and therefore have an important signaling function. For the MUFIs themselves, although being multifunctional increases opportunities, it is also a challenge to find the right balance between the different functions and not to lose sight of the economic side of the business. Local governments can support MUFIs by providing space for them, room to experiment, adapting regulations to getting MUFIs out of the “grey zones” of legislation, and by starting to strategically think about food in their city region.
Dysfibrinogenaemia secondary to rocuronium‐induced anaphylaxis
Authors: Orr Tim , Rosser Jon
Published: October 2017

We present a case of rocuronium‐induced anaphylaxis resulting in cardiac arrest that was complicated by the complete qualitative and quantitive absence of fibrinogen on viscoelastic and laboratory coagulation testing. The abnormalities resolved following the administration of fibrinogen concentrate. We review the literature and discuss the management of this uncommon complication of anaphylaxis.
Влияние состава покровного слоя на электронные характеристики квантовых точек InAs/GaAs
Authors: Горшков А.П. , Волкова Н.С. , Воронин П.Г. , Здоровейщев А.В. , Истомин Л.А. , Павлов Д.А. , Усов Ю.В. , Левичев С.Б.
Published: October 2017

Заращивание массива самоорганизованных квантовых точек InAs/GaAs слоем квантовой ямы InGaAs приводит к увеличению их размера за счет обогащения области вблизи вершины квантовых точек индием, что уменьшает энергию основного оптического перехода в квантовых точках на 50 мэВ и смещает волновую функцию дырки по направлению к вершине квантовой точки. DOI: 10.21883/FTP.2017.11.45088.02
Влияние электрического поля на соотношение параметров Рашба и Дрессельхауза в гетероструктурах А-=SUP=-III-=/SUP=-B-=SUP=-V-=/SUP=-
Authors: Дегтярев В.Е. , Хазанова C.В. , Конаков А.А.
Published: October 2017

С помощью 8-зонной модели Кейна и конечно-разностной схемы с дискретизацией в координатном пространстве численно выполнены расчеты энергий подзон размерного квантования и огибающих волновых функций для квантовых ям [001] на основе полупроводников АIIIBV со структурой цинковой обманки. Исследовано влияние зонных параметров квантовой ямы, а также величины внешнего электрического поля, ориентированного вдоль направления роста структуры, на соотношение параметров спин-орбитального взаимодействия Рашба и Дрессельхауза. Показано, что в структурах GaAs/InGaAs при определенных значениях электрического поля возможно равенство параметров спин-орбитального взаимодействия, что является условием формирования устойчивых спиновых "хеликсов". Установлено также, что в симметричных ямах GaAs/InGaAs при определенных ширинах ям и химическом составе барьеров может исчезать линейное по волновому вектору спин-орбитальное взаимодействие. DOI: 10.21883/FTP.2017.11.45091.05
Неоднородное распределение легирующей примеси в A-=SUP=-III-=/SUP=-B-=SUP=-V-=/SUP=- нитевидных нанокристаллах
Authors: Лещенко Е.Д. , Дубровский В.Г.
Published: October 2017

Работа посвящена исследованию пространственного распределения концентрации легирующей примеси в нитевидных нанокристаллах полупроводниковых соединений AIIIBV, выращиваемых методом молекулярно-пучковой эпитаксии. Найдена эволюция функции распределения легирующей примеси в результате решения краевой задачи диффузии. Показано, как в рамках построенной модели возникает неоднородность концентрации примеси, наблюдаемая экспериментально при легировании GaAs нитевидных нанокристаллов бериллием и в некоторых других системах материалов. DOI: 10.21883/FTP.2017.11.45094.08
Распределение функций спаривания в сверхпроводящем спиновом вентиле SF1F2
Authors: Гайфуллин Р.Р. , Деминов Р.Г. , Тагиров Л.Р. , Куприянов М.Ю. , Голубов А.А.
Published: October 2017

Получено распределение спин-синглетной, близкодействующей с нулевой проекцией спин-триплетной и дальнодействующей с проекцией ±1 спин-триплетной компонент сверхпроводящего спаривания в различных режимах переключения спинового вентиля трехслойной гетероструктуры (сверхпроводник/ферромагнетик/ферромагнетик). Обсуждается распределение компонент в качестве основной причины поведения температуры сверхпроводящего перехода как функции угла между магнитными моментами ферромагнитных слоев в этих режимах. Работа выполнена при финансовой поддержке РФФИ (проекты 16-02-01171-a, 14-02-31002-mol\_a, 15-32-20362-bel\_a\_ved), DFG HO 955/9-1, НШ-8168.2016.2, РНФ 15-12-30030 и программы повышения конкурентоспособности Казанского федерального университета. Л.Р.Т. благодарит Президиум РАН (программа "Актуальные проблемы физики низких температур") за частичную поддержку. DOI: 10.21883/FTT.2017.11.45043.02k
Методы управления спиновой инжекцией в спиновых светоизлучающих диодах InGaAs/GaAs/Al-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=-/CoPt
Authors: Дорохин М.В. , Ведь М.В. , Дёмина П.Б. , Здоровейщев А.В. , Кудрин А.В. , Рыков А.В. , Кузнецов Ю.М.
Published: October 2017

Исследована спиновая инжекция в спиновых светоизлучающих диодах (ССИД) CoPt/Al2O3/(Al)GaAs. Обнаружены осцилляции степени циркулярной поляризации при варьировании расстояния между активной областью ССИД и CoPt ферромагнитным инжектором. Осцилляции не зависят от материала ССИД (GaAs или AlGaAs), а также от типа инжектированных спин-поляризованных носителей (электроны или дырки), и связываются с действием перпендикулярного магнитного поля на инжектированные спин-поляризованные носители, которое обусловливает их прецессию. В процессе переноса к активной области на расстоянии 50-100 nm от инжектора z-компонента спина меняет фазу, в эксперименте это регистрируется как изменение знака степени циркулярной поляризации электролюминесценции. Предположительно, источником внутреннего магнитного поля, приводящего к спиновой прецессии, является магнитное поле неоднородно намагниченного контакта CoPt. Работа выполнена в рамках реализации государственного задания --- проект N 8.1751.2017/ПЧ Минобрнауки России, при поддержке РФФИ (гранты N 15-02-07824\_а, 16-07-01102\_а и 17-37-80008\_мол\_эв\_а), стипендии (конкурс СП-2015) и гранта (МК-8221.2016.2) президента Российской Федерации. DOI: 10.21883/FTT.2017.11.45050.13k
Управление циркулярной поляризацией электролюминесценции в спиновых светоизлучающих диодах на основе гетероструктур InGaAs/GaAs/delta
Authors: Малышева Е.И. , Дорохин М.В. , Дёмина П.Б. , Здоровейщев А.В. , Рыков А.В. , Ведь М.В. , Данилов Ю.А.
Published: October 2017

Проведено исследование циркулярно-поляризованной люминесценции светоизлучающих структур InGaAs/GaAs с дельта-легированным слоем Mn в GaAs барьере. Выполнено варьирование параметров структур: однородное и дельта-легирование акцепторной примесью, удаление донорного легирования из технологического процесса. Получено, что величина и знак степени циркулярной поляризации люминесценции существенно зависят от выбранного технологического режима. Одномерное моделирование волновых функций структур выявило хорошее согласие между параметрами циркулярно-поляризованной люминесценции и пространственным распределением волновых функций тяжелых дырок относительно дельта-слоя Mn. Работа выполнена в рамках реализации государственного задания. Проект N 8.1751.2017/ПЧ Минобрнауки России, при поддержке РФФИ (гранты N 15-02-07824\_а, 16-07-01102\_а), гранта (МК-8221.2016.2) Президента Российской Федерации. DOI: 10.21883/FTT.2017.11.45051.18k