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Field surveys were conducted on golf courses reporting the inability of imidacloprid to control white grubs (Coleoptera: Scarabaeidae) when applied preventively. Surveys of five sites with significant past imidacloprid use (>10 years) revealed significantly greater white grub populations in rough‐mown turf following imidacloprid treatment than that of adjacent short‐mown fairways. Additionally, spatial analysis by distance indicEs (SADIE) analyses demonstrated a positive correlation between white grub and thatch spatial patterns. To investigate the impact of thatch on imidacloprid efficacy and translocation throughout the turfgrass plant, greenhouse experiments were conducted using turf with differing thatch levels. Imidacloprid concentrations in soil and plant tissues were measured with high‐performance liquid chromatography (HPLC) and compared to values obtained through an enzyme‐linked immunosorbent assay (ELISA) kit to determine if the latter could be a cost‐effective alternative in future studies. ELISA provided reliable estimates of concentrations of imidacloprid compared to HPLC, with only minor discrepancies noted across different types of treatments and assessment timings. Despite finding higher imidacloprid levels in leaf tissues compared to roots and some differences in concentration across thatch treatments, there was no clear pattern showing that thatch thickness significantly affects imidacloprid penetration or accumulation in plant tissues or soil over time. These findings suggest that factors other than thatch thickness may contribute to the observed field failures of imidacloprid in controlling white grubs. Further research is necessary to identify these factors and optimize the use of imidacloprid in turfgrass pest management strategies. [ABSTRACT FROM AUTHOR]

Turfgrass research based on inoculations with commercial products containing nitrogen‐fixing endophytes as an alternative to synthetic nitrogen (N) fertilizers has yielded inconclusive results, indicating a lack of understanding of the colonization and stability of diazotrophic endophytes in turfgrasses. Potential factors influencing these results are turfgrass traditional management practices. In this study, we identified and compared endophytic diazotrophic communities and their associated soil counterparts using amplicon sequencing of the nitrogenase iron protein (nifH) of 36 surfaced sterilized CitraBlue St. Augustinegrass cultivar [Stenotaphrum secundatum (Walter) Kuntze] sprigs and 12 aggregated soil samples. Samples were collected from a CitraBlue cultivar mowed either at 5 or 10 cm, with and without thatch removal, and fertilized at 98, 195, or 293 kg N ha−1 year−1. The different communities of endophytic diazotrophs were correlated to turfgrass quality related parameters such as normalized difference vegetation index (NDVI), normalized difference red edge index (NDRE), N leaf content, and visual quality as affected by management practices. CitraBlue endophytic and soil diazotrophic communities were significantly different for alpha diversity (p < 0.0001) and beta diversity (p < 0.001). Both mowing height (p < 0.001) and N fertilization rate (p < 0.05) had a significant effect on the diversity of endophytic diazotrophs. According to the redundancy analysis, turfgrass quality related parameters explained 14.3% of the variance in the endophytic diazotrophic communities. Findings from this research demonstrate that the evaluated management practices alter the endophytic diazotrophic communities of CitraBlue. [ABSTRACT FROM AUTHOR]

This study evaluates the effectiveness of fine‐tuning a semantic segmentation model to identify and quantify dollar spot in turfgrasses, the most extensively managed and researched disease of turfgrasses worldwide. Using the DeepLabV3+ model, recognized for its capability to segment complex shapes and integrate multi‐scale contextual information, the research leveraged a diverse dataset comprising various turfgrass species, disease stages, and lighting conditions to ensure robust model training. The trained model is able to identify and segment disease instances accurately and precisely, and the results indicate the potential for model‐based assessment to outperform traditional visual assessment methods in speed, accuracy, and consistency. The development of deep learning models on extensive datasets like ImageNet requires significant computational resources. However, by fine‐tuning a pretrained semantic segmentation model, we adapted it for disease segmentation using only a standard personal computer's graphics processing unit. This approach not only conserves resources but also highlights the practicality of deploying advanced deep learning applications in turfgrass pathology with limited computational capacity. The proposed model provides a new tool for turfgrass researchers and professionals to rapidly and accurately quantify this important disease under real‐world growing conditions. Additionally, the findings suggest the potential to apply deep learning algorithms to other turfgrass diseases to support data‐driven decisions. This could enhance disease management practices and improve decision‐making processes for fungicidal treatments, thereby improving the economic and environmental sustainability of turfgrass management. [ABSTRACT FROM AUTHOR]

Shade stress is a common problem encountered in turfgrass management situations worldwide. Shade reduces photosynthetic photon flux (PPF), alters light quality, reduces air movement, and may introduce tree root competition. As a species, Kentucky bluegrass (Poa pratensis L.) possesses relatively poor shade tolerance, which limits its use in reduced light environments. However, genetic alteration of the gibberellic acid enzyme pathway has shown promise in some plant species for improving growth in shade. The objective of this 2‐year field study was to determine the comparative performance under reduced PPF and determine minimal daily light integral (DLIm) requirements for acceptable quality of a conventional (CONV) Kentucky bluegrass (KBG) blend and gibberellic acid 2‐oxidase (GA2ox) transformed "ProVista" (PV) KBG. A 2‐year field study was conducted under neutral density shade treatments producing monthly daily light integrals averaging from ∼5.8 (90% shade) to 48 mol m−2 day−1 (full sun) for mid‐June through October study periods. Based on nonlinear regression of mean monthly DLI during the study period versus turfgrass quality (TQ) at the end of each study period, DLIm was found to range from 7.5 to 10 mol m−2 day−1 for PV and from 22.5 to 26.2 mol m−2 day−1 for CONV KBG. Improved TQ of PV under low light intensities may be associated with reduced rates of leaf elongation, greater stand density, higher chlorophyll concentrations, and darker green color compared to CONV KBG. Although shade duration did not exceed 4 months, the results suggest that GA2ox‐transformed PV KBG possesses improved tolerance to reduced PPF compared to CONV KBG. Core Ideas: Limited data are available on minimal light requirements of Kentucky bluegrass cultivars.ProVista shows improved turf quality and color and reduced vertical regrowth relative to conventional under low photosynthetic photon flux.ProVista required minimal daily light integral of 7.5–10 mol m−2 day−1, while conventional Kentucky bluegrass requires 22–26 mol m−2 day−1. [ABSTRACT FROM AUTHOR]

Increasing N use efficiency (NUE) is desirable in turfgrass management. Traditional definition of NUE in turfgrass is essentially the inverse of nitrogen concentration in the clippings and is often evaluated once in a growing season. In this experiment, we followed the Brenderse and Aerts' definition of NUE as the product of mean residence time (MRT) and nitrogen productivity (NP). The objective of this experiment was to identify NP changes over time in Kentucky bluegrass cultivars at different N levels under deficit irrigation. Nine Kentucky bluegrass (Poa pratensis L.) and two hybrid bluegrass cultivars from 10 phenotypic classes were tested under N rates of 10 and 40 g m−2. Deficit irrigation at 60% of the evapotranspiration was imposed. The results showed interaction effects on NP from N level, irrigation, and cultivar. Low‐N treatment resulted in higher NP values as compared to high‐N for 'Merit' and 'Martha'. No NP difference existed between N or irrigation levels for 'Blue ghost', 'Geronimo', 'Heidi', 'Bandera', 'Impact', 'Fielder', 'Jackrabbit', and 'Park'. 'Rhythm' showed lower NP values in high‐N combined with full irrigation compared to other treatments. In general, increasing N levels resulted in lower NP, but higher nitrate reductase activity (NaR) and higher net photosynthesis. No N by irrigation interaction effect was detected for effective quantum yield or NaR. In conclusion, leaf‐level NP was shown to be an effective parameter for in‐season monitoring of the above‐ground NUE of Kentucky bluegrass, which provided more dynamic information than clipping yields or a one‐time NUE calculation based on traditional definition. [ABSTRACT FROM AUTHOR]

Impacts of long‐term fertilization and cultivation were evaluated on nematode communities associated with tall fescue turfgrass following 11 years of treatment applications. Fertilizer treatments of biosolid, synthetic, and plant‐based fertilizers and cultivation treatments of 0×, 1×, and 2× aerification passes were applied to randomized and replicated tall fescue plots at the University of Maryland Paint Branch Turfgrass facility in College Park, Maryland. Free‐living and plant‐parasitic nematodes were identified, enumerated, and categorized into functional groups. Nematode count data were compared using generalized linear mixed modeling with negative binomial distribution and two‐way ANOVA was used to compare nematode ecological indices. Biosolid treatments resulted in lower omnivore‐predator densities than plant‐based fertilizer treatments (p ≤.001) and significantly greater Hoplolaimus densities than plant‐based fertilizer plots (p ≤.05). Synthetic fertilizer applications resulted in the greatest Eucephalobus (p ≤.05) and total bacterivore densities (p ≤.001) of all fertilizer treatments. Plant‐based fertilizer‐treated plots had the largest Maturity Index cp 2‐5 and Structure Index (p ≤.05). Cultivation of 1× resulted in fewer total bacterivore densities than 2× (p ≤.01) while omnivore‐predator densities were greater in 1× than 0× (p ≤.001). Plant health, as measured by NDVI, was lowest in biosolid‐treated turfgrass (p ≤.05). These findings suggest that long‐term turfgrass management practices can have variable impacts on nematode abundance and community structure in tall fescue and provide insights into ecological impacts of turfgrass management practices. [ABSTRACT FROM AUTHOR]

Turf‐type bermudagrass is susceptible to winterkill when grown in transition zone climates. Minimizing water use in turfgrass management is of societal significance. African bermudagrass (Cynodon transvaalensis Burtt‐Davy) has been extensively used to cross with common bermudagrass (C. dactylon Pers. var. dactylon) in the creation of F1 hybrid cultivars. Little information regarding the molecular basis of winter survivability and drought resistance in African bermudagrass is available. Accordingly, the objectives of this study were to quantify genetic variability and identify quantitative trait loci (QTL) associated with winter survivability traits (spring greenup, SG; spring greenup percent green cover, SGPGC; winterkill, WK), and leaf firing (LF) in African bermudagrass. A total of 109 first‐generation self‐pollinated (S1) progeny of 'OKC1163' were evaluated in a field trial in a randomized complete block design with three replications for four seasons. Significant genetic variation existed for all the traits examined, and the broad‐sense heritability estimates ranged from.36 to.54 for the winter survivability traits and.80 for LF. Ten QTL were identified for winter survivability traits and two for LF based on a preexisting high‐density linkage map, which was aligned, reoriented, and renamed as to a recently published reference genome. Seven of 12 QTL were consistently identified at least in 2 yr. The colocation of two QTL, one for winter survivability and another for LF, suggests the possibility of improving both traits together. Findings provide new insights to genetic control of winter survivability traits and LF and contribute genetic resources for marker‐assisted selection in turf‐type bermudagrass improvement. Core Ideas: Winter survivability traits and LF are critical to the development of new turf‐type bermudagrass cultivars.One hundred and nine S1 African bermudagrass progeny were characterized for winter survivability and LF. We identified 10 QTL associated with winter survivability and two QTL for LF. [ABSTRACT FROM AUTHOR]

The article acknowledges the important role of volunteer reviewers in maintaining the editorial standards and quality of research in the scientific journal Crop, Forage & Turfgrass Management. The article expresses appreciation to the reviewers who provided critical comments and helpful suggestions for manuscripts during the past year. The list of reviewers is extensive, but it may not be complete due to difficulties in collating information from various sources. The article extends apologies to any reviewers whose names were not included. [Extracted from the article]

Precision turfgrass management (PTM) is a combination of methods and technologies proposed to increase the resiliency of golf courses by improving input efficiency while maintaining the function and aesthetics of the playing surface. However, there is no recent review describing the status of precision management in turfgrass. The objectives of this review were to (a) summarize peer reviewed research on precision technology for turfgrass management, (b) describe adoption of PTM‐based tools, and (c) propose an agenda of research priorities to advance and promote PTM adoption. Of the articles reviewed, 94% documented the accuracy of sensors to detect turfgrass performance and stressors before or during visual symptoms. Only 6% of the research reviewed focused on developing models or decision support systems to quantify the relationship among reflectance, nitrogen uptake, visual quality, biomass production, and irrigation which are required for precision management by golf course superintendents. Efficacy or value of using PTM methods and technologies have not been reported. Golf course superintendents lack of knowledge about PTM, and lack of quantification of benefits of PTM pose limitations to promote adoption. Increasing the adoption of PTM will require research to focus additionally on automating sensor data processing; quantifying costs, benefits, and value of adopting PTM; and simplifying input applications in a PTM system. This review described the status of precision management in golf course turfgrass and shed light into the need for research to develop models and decision support tools for precision management of golf course turfgrass. Core Ideas: Precision turfgrass management is proposed to increase golf course resiliency.Research has focused on measuring performance and stressors of turfgrass.Superintendents' lack of knowledge about precision turfgrass management poses a challenge toward future adoption.Future research should focus on developing precision turfgrass management decision support systems for golf course turfgrass. [ABSTRACT FROM AUTHOR]

Silicon (Si) is a "quasi-essential" element that helps plants to overcome various abiotic and biotic stresses. This reviewsummarizes research which examined application of Si in turfgrass management and its impact on plant health. Research on inclusion of Si in turfgrass has largely centered upon three areas: plant disease suppression, improvement in wear tolerance, and reductions in drought and salinity stress. Of these, the ability of Si to reduce turf diseases has received the most attention, with applications of Si often reducing various diseases, including gray leaf spot, dollar spot, and brown patch, in creeping bentgrass, bermudagrass, perennial ryegrass, and St. Augustinegrass. One potential constraint to its effectiveness is that Si application rates for disease reduction are often quite high (e.g., rates as high as 400 to 2,000 kg Si ha-1). Responses were also variable with turfgrass species, soil type, and soil Si content, and the measured response was often not great enough to produce turf of desirable quality without additional use of fungicides. More research is needed in the area of Si and turf wear, as the use of Si to "harden" turfgrass and improve wear and ball roll is widely marketed in turfgrass maintenance. Further research is also needed to identify best soil extractants for measuring soluble Si and to calibrate this extractable Si for the determination of critical levels of soil Si across soil types and turfgrass species. [ABSTRACT FROM AUTHOR]

Spring dead spot (Ophiosphaerella herpotricha, O. korrae, O. narmari; SDS) is among the most destructive diseases of bermudagrass [Cynodon dactylon (L.) Pers.] and hybrid bermudagrass (C. dactylon x C. transvaalensis Burtt Davy) in the Transition Zone of the United States. Spring dead spot's primary causal agents in the United States, Ophiosphaerella korrae and O. herpotricha, infect bermudagrass in the fall with symptoms appearing in the spring when winter dormancy breaks. Patches of necrotic turfgrass often reoccur in the same location and expand into surrounding areas. Chemical control options are often expensive or provide inconsistent results. Our objectives were to develop SDS incidence maps, analyze these maps, and evaluate suppression efficacy of chemical applications guided by incidence‐based maps. Digital imagery captured with an unmanned aerial vehicle (UAV) was used to create SDS incidence maps in the spring of 2016, 2017, and 2018. In the fall of 2016 and 2017, a targeted, site‐specific penthiopyrad treatment was evaluated against blanket, full‐coverage applications of penthiopyrad and tebuconazole, and a nontreated control. Treatments were compared using digital image analysis of diseased area (DA) and post‐treatment SDS patch count (PC). Across both metrics, the penthiopyrad treatments had significantly less disease than both the tebuconazole and nontreated control in 2016–2017. Targeted penthiopyrad compared favorably to full coverage penthiopyrad for DA and PC in 2016–2017, but full‐coverage penthiopyrad was superior to targeted penthiopyrad and tebuconazole in 2017–2018 for both DA and PC. Targeted penthiopyrad using SDS incidence maps required 51% less fungicides in 2016–2017 and 65% less in 2017–2018 when compared to full‐coverage penthiopyrad. Core Ideas: Spring dead spot (SDS) suppression methods and strategies using precision turfgrass management (PTM).The use of unmanned aerial vehicles (UAV) and aerial mapping in turfgrass management.The use of GPS‐guided, targets applications for disease suppression. [ABSTRACT FROM AUTHOR]

Drought tolerance and rapid post‐stress recovery are critical survival strategies for turfgrass management in areas with limited rainfall and irrigation. This study sought to determine whether elevated CO2 could improve drought tolerance in rhizomatous Kentucky bluegrass (Poa pratensis L.) by protecting rhizomes from stress damage and promote regrowth and regeneration of daughter plants from rhizomes upon rewatering. Plants (cv. 'Baron') were grown at elevated CO2 concentration (800 μl L−1) or ambient CO2 concentration (400 μl L−1) for 28 d and then exposed to well‐irrigated conditions (control) or drought stress by withholding irrigation for an additional 28 d, followed by rewatering in growth chambers. Elevated CO2–treated plants had significantly higher leaf relative water content, visual quality, and membrane stability during drought compared with ambient CO2–treated plants. Rhizome nodes of elevated CO2–treated plants maintained significantly higher viability and lower content of abscisic acid and auxin under drought stress. In response to rewatering, plants previously exposed to drought stress under elevated CO2 exhibited increased growth of new shoots measured as total shoot biomass and daughter‐plant biomass, and an increased number of rhizomes, as well as greater canopy density compared with plants at ambient CO2. This study suggested that elevated CO2 concentration was able to protect rhizomes from drought damage and reactivate rhizomes for regeneration of new plants when drought was relieved by irrigation. [ABSTRACT FROM AUTHOR]

A 2-yr study was conducted at Michigan State University (MSU) and the University of Arkansas (UARK) to identify creeping bentgrass (Agrostis stolonifera L.) putting green management practices that minimize or exacerbate visible wear damage (VWD) caused by aggressive golf shoes or cleats. Management treatments included different levels of grooming (none vs. three times weekly at a depth of 0.5 mm), lightweight rolling (none vs. three times weekly), sand topdressing (none vs. every 14 d at the rate of 0.6 L m-2), and nitrogen fertility (low N vs. high N every 14 d) applied as urea at the rates of 0.6 or 1.2 g m-2. Rolling significantly increased VWD at UARK in both years and at MSU in 2017. When increases in VWD occurred on rolled plots, there were also significant increases in moisture in the top 3.8 cm of the root zone. Higher fertility consistently increased VWD at UARK throughout the study and after a single traffic event at MSU. Throughout the trial, grooming and sand topdressing occasionally reduced VWD at both locations. These results will help agronomists and golf course superintendents fine-tune cultural practices to mitigate VWD on intensively managed creeping bentgrass putting greens. [ABSTRACT FROM AUTHOR]

Azoxystrobin is a broad-spectrum strobilurin fungicide used widely in turfgrass systems, including lawns. Previous research has shown that various management practices influence pesticide dislodgement from turfgrass; however, limited research has been performed to determine their effect on azoxystrobin dislodge. A field experiment was conducted in Raleigh, NC, to quantify dislodgeable azoxystrobin (0.61 kg ai ha-1) foliar residue from tall fescue [Lolium arundinaceum (Schreb.) S.J. Darbyshire] across formulations (sprayable or granular), application timings (AM [0700 h Eastern Standard Time] or PM [1400 h Eastern Standard Time]), and postapplication irrigation timings (4 or 48 h after treatment [HAT]). Sample collection occurred 1, 2, 3, 4, 8, or 16 d after treatment (DAT). Evaluated management practices affected dislodgeable azoxystrobin, most notably from 1 to 4 DAT. Sprayable azoxystrobin applied in the PM resulted in greater azoxystrobin dislodged (1.0-8.0% of applied) compared with AM (0.3-5.5%), which were both greater than granular azoxystrobin applied in the AM or PM (<0.1-2.8%) from 1 to 4 DAT. Within sprayable azoxystrobin, five times greater azoxystrobin was dislodged by delaying postapplication irrigation until 48 HAT (1.2-11.8% of applied) compared with irrigation 4 HAT (0.2-1.2%) from 1 to 4 DAT. Information from this study improves our understanding of factors affecting pesticide dislodge and can be incorporated into turfgrass management strategies to minimize potential human pesticide exposure. [ABSTRACT FROM AUTHOR]

Improved vegetative bermudagrasses such as 'Latitude 36' [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt‐Davy] provide desirable playing surfaces for sports fields and golf courses in the transition zone of the United States because of their cold tolerance and exceptional density. However, establishing bermudagrass from vegetative stems (sprigs) during the standard planting times of mid‐spring through to mid‐summer in this region requires regular and frequent moisture after planting, essentially prohibiting the establishment of these grasses where supplemental irrigation is unavailable. Trials were conducted in 2017–2018 at the Turfgrass Research Center of Virginia Tech to evaluate the establishment success of sprigged Latitude 36 in January, February, or March under non‐irrigated conditions. Within sprig blocks, the addition of 0.25 inch compost, a turf blanket, and a combination of these were compared for improved establishment success. Digital image analysis was used to quantify green bermudagrass coverage over time. Ultimately, a targeted mean 90% bermudagrass coverage was achieved within 5 wk of removing the turf blankets in Blacksburg, VA, regardless of the initial sprigging date. Turf blankets alone and in combination with compost increased initial bermudagrass coverage after blanket removal but did not impact the final establishment rate. Data from these studies imply that hybrid bermudagrass can be sprigged successfully without irrigation during winter months, and that covering sprigs after planting had no long‐term impact on establishment. Core Ideas: Dormant sprig date did not impact long‐term success of bermudagrass establishment.Turf blanket and/or compost had a short‐lived impact on bermudagrass establishment.Sprigs harvested during spring transition may be sensitive to late freeze events. [ABSTRACT FROM AUTHOR]

Broadly applicable management strategies to prepare turfgrasses for overwintering are lacking. This research aimed to investigate whether chemical priming in the field may improve the survival of the perennial form of annual bluegrass (Poa annua L.) after ice encasement. Annual bluegrass field plots were treated in the summer and fall of 2017 and 2018 with salicylic acid (SA), jasmonic acid (JA), trinexapac‐ethyl (TE), Civitas (active ingredient: mineral oil), and combinations of each chemical or were not treated. Civitas and Civitas + TE‐treated plants had the highest level of turfgrass quality throughout the summer and fall. Normalized difference vegetative index (NDVI) and dark green color index (DGCI) indicated that JA + TE and Civitas + TE had consistently higher values than controls on many dates. Plant plugs were transferred from the field to a low temperature growth chamber (–4°C) for ice encasement or no ice treatment. Following ice encasement for 40 or 80 d, all treatments except for TE alone showed some significant improvements in annual bluegrass recovery. Treatment of annual bluegrass in the summer and fall with Civitas, TE + Civitas, JA, and TE + JA preceding ice encasement may improve recovery from prolonged ice encasement and be useful turf management practices. Without ice encasement at low temperature, Civitas was the only treatment that improved recovery. The chemical treatments that improved ice encasement recovery may alter annual bluegrass fatty acid ratios, such as by increasing the unsaturated fatty acid, linoleic acid. [ABSTRACT FROM AUTHOR]

Plant‐based antifungal agents offer an alternative to synthetic fungicides in amenity turfgrass disease management. Poacic acid is a by‐product of the biofuel production process that has exhibited antifungal activity, and the objective of this research was to determine its ability to serve as an effective management tool for economically important turfgrass diseases such as dollar spot and snow moulds. In vitro and field tests were conducted in Wisconsin and Michigan, USA from 2015 to 2017 to determine the efficacy of poacic acid in suppressing the economically important turfgrass pathogens Clarireedia jacksonii and Microdochium nivale. Poacic acid demonstrated strong antifungal activity against both pathogens in vitro, inhibiting growth of C. jacksonii and M. nivale by 93% and 74% relative to nonamended media, respectively. Poacic acid reduced dollar spot in the field in one of two years, but failed to suppress snow mould when applied alone. Poacic acid was an effective mix partner for snow mould control when combined with a synthetic fungicide, an important attribute because no single fungicide currently on the market provides acceptable snow mould control under heavy disease pressure. Future research should focus on improving poacic acid field efficacy so that it can be incorporated into plant‐based disease management strategies for amenity turfgrass. [ABSTRACT FROM AUTHOR]

The present study was conducted to explore the spatiotemporal relationship between several plant and soil properties on two natural turfgrass sports fields comprised of native and sand-capped soils before and after irrigation. Minimal differences in strength of relationship and spatical variability among field properties occurred from before to after irrigation at both fields. A number of significant relationships between field properties were observed overall, although significance did not always result in comparable spatial distributions. Additionally, significant relationships on the native soil field were not always significant on the sand-capped field. Results exemplify that a single, typical irrigation event will not noticeably change the strength of relationship or spatial distribution between field properties. Furthermore, the strength of relationship and its influence on spatial variability between field properties can be site-specific, and soil type plays an important role in this phenomenon. This information is valuable to conduct precision turfgrass management practices for potential improvement in the uniformity of multiple field properties, and also to aid in efficient subsequent sampling for future spatial map creation. [ABSTRACT FROM AUTHOR]

Recent advances in small unmanned aircraft systems (sUAS) and sensors may improve accuracy and efficiency in turfgrass research and management compared with conventional methods. We evaluated the ability of sUAS combined with ultra‐high spatial resolution remote sensing to detect early drought stress. Results were compared with ground‐based techniques in creeping bentgrass (Agrostis stolonifera L.) irrigated at different levels from well‐watered to severe deficit (100 to 15% evapotranspiration [ET] replacement). Small UAS‐based measurements with a modified digital camera included three reflectance bands (near infrared [NIR, 680–780 nm] and overlapping green [G] and blue [B] bands [400–580 nm]) and eight derived vegetation indices (VIs). Ground‐based measurements included soil volumetric water content (VWC), turfgrass quality (TQ), green cover (GC), soil temperature (Tsoil), and reflectance with handheld optical sensors. Declines in VWC in deficit‐irrigation treatments were detected with NIR and six of eight VIs from sUAS, and the normalized difference vegetation index (NDVI) and red band reflectance from a handheld sensor, before symptoms appeared in TQ and GC. The most consistently sensitive parameters of sUAS throughout the 3‐yr study were NIR and GreenBlue VI [(G − B)/(G + B)], which detected drought stress >5 d before decreases in TQ. Results indicate that ultra‐high spatial resolution remote sensing with sUAS detected drought stress before it was visible to a human observer and could be valuable for improving irrigation management in turfgrass. [ABSTRACT FROM AUTHOR]

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Core Ideas: The fall is the optimum time to control winter annual and perennial broadleaf weeds.More information is needed on postemergence herbicide safety in the fall as buffalograss enters winter dormancy.Many postemergence herbicides can be safely applied to buffalograss entering winter dormancy with no effect on spring greenup.Turf managers have many herbicide and application timing options for weed control in buffalograss. [ABSTRACT FROM AUTHOR]

Core Ideas: More information is needed on non‐target turf injury caused by overspray of human insect repellents.There are differences in the magnitude of turf injury in response to human insect repellents.Significant turf injury for varying lengths of time may result from human insect repellent products, especially for products containing DEET. [ABSTRACT FROM AUTHOR]

Core Ideas: Early fall Proxy (ethephon) applications effectively suppress Meyer zoysiagrass seedheads in spring.Apply Proxy in late‐September when days are approximately 12 hours long to suppress zoysiagrass seedheads.Tank‐mixtures of Proxy with large patch fungicides reduce application labor and equipment costs. 'Meyer' zoysiagrass (Zoysia japonica Steud.) is used on golf courses throughout the transitional climatic zone because of its aesthetic and functional quality and tolerance to abiotic stresses. However, a key problem with Meyer zoysiagrass is that it produces seedheads in the spring that reduce aesthetics and increase golf course maintenance costs. The objective of this experiment was to quantify the efficacy of Proxy (ethephon) on Meyer zoysiagrass seedhead suppression at three locations when applied in fall before winter dormancy and in spring prior to seedhead production. The early fall application timing of Proxy provided > 90% suppression of zoysiagrass seedheads with < 10% injury. Late fall and spring Proxy applications provided little seedhead suppression. The early fall application timing that successfully suppressed Meyer zoysiagrass seedheads in our experiment was applied from 23 to 29 September across locations to 100% green zoysiagrass; on dates with a photoperiod of 11.9 to 12.1 h; and following the accumulation of < 14 cooling degree days (20°C base temperature). This research provides turf managers insight on how to best suppress Meyer zoysiagrass seedhead production. [ABSTRACT FROM AUTHOR]

Fungicides are often applied to control root diseases that affect golf course turf. Post-application irrigation and wetting agents are suggested to improve fungicide performance by facilitating downward movement into the root zone. How irrigation and wetting agent treatments influence fungicide distribution in the turf profile remains unclear based on existing literature. The research objective was to investigate the influence of a wetting agent and post-application irrigation on the distribution of modern fungicides in a sand-based creeping bentgrass (Agrostis stolonifera L.) putting green. Fungicides used in two distinct experimental runs in field plots included azoxystrobin, fluxapyroxad, propiconazole, and pyraclostrobin. Fungicide + irrigation, fungicide + wetting agent, and fungicide + irrigation + wetting agent treatment effects were compared with a fungicide-only treatment. Turf was sampled at -1, 0, 3, 7, 10, 14, 21, and 28 d after fungicide application. Core samples were collected and separated into three components--verdure/ thatch, and soil at two depths, 2 to 5 and 5 to 8 cm. Fungicide was extracted from each turf component and analyzed thereafter using liquid chromatography--triple quadrupole mass spectroscopy. Results showed that the majority of fungicide was captured by verdure/thatch, and that fungicide concentration in verdure/ thatch was 1 to 2 orders of magnitude higher compared with other turf components. Further, in almost every case, there was no measurable effect of irrigation, wetting agent, or the combination on fungicide distribution in the turf profile. Research results can help improve understanding of fungicide distribution in turf and provide scientific context for recommendations regarding root disease control in golf course turf. [ABSTRACT FROM AUTHOR]

Abstract: Furnished cages for laying hens have advantages in allowing normal behaviors and maintaining productivity. As the cost of introduction is a barrier for farms, we developed furnished cages that re‐use conventional cages. To determine the minimum and functional cage design, we compared six designs, combinations of two floor designs (artificial turf or wire cage floor) and three screening designs in the integrated area (no screening, one entrance side or four sides). In total, 144 hens were used, and we measured behavior, physical condition and productivity. Comparing the floors, the percentages of hens performing dust‐bathing and laying eggs in the integrated area were higher in cages with turf than wire floor (P < 0.05 for both). Comparing the screening, dust‐bathing, litter‐exploring and active behavior tended to be more frequent in cages with the integrated area screened on one side than four sides. Feather damage was lower in cages with the integrated area screened on one side than with no screening (P < 0.05). These results suggest that the cage design with an integrated area with artificial turf floor, screened on one side, was effective for furnished cages that re‐use conventional cages. [ABSTRACT FROM AUTHOR]

Specific scope This Standard describes the control procedures aiming to monitor, contain and eradicate Microstegium vimineum. Specific approval and amendment First approved in 2017-09. [ABSTRACT FROM AUTHOR]

The article discusses research on U.S. and Canadian consumer preferences for turfgrass, noting possible market segmentation. Topics include the views of consumers regarding maintenance attributes, the opportunity for greater production of low-input species by the turfgrass seed industry, and generational differences among turfgrass consumers.

In the United States, there is a growing need for turfgrass management practices that protect community and environmental health. The proportion of the developed landscape in the United States covered by turfgrass is significant and, at present, covers at least 1.9% of the total land area and comprises 60% in parts of the country. As urbanization progresses, there is a critical need to re-examine turf management practices that reduce reliance on pesticide and fertilizer inputs while contributing additional beneficial ecosystem services. In this review, we discuss the functional role of turfgrass in urban ecosystems. We identify key urban ecosystem processes associated with turfgrass and evaluate the potential to integrate biodiversity into their design and management. Specifically, we summarize research on the Biodiversity and Ecosystem Function theory that shows enhanced C storage, N retention, and weed suppression in natural and managed ecosystems, which are traits that are relevant to turfgrass systems. Enhancing biodiversity in turfgrass systems could increase ecosystem services in urban landscapes and should be considered a component of sustainable management practices. [ABSTRACT FROM AUTHOR]

Mowing remains one of the most energy-intensive cultural practices in maintaining a turf sward. Turfgrass systems can become a larger net C sink if mower emissions are reduced. Establishing slow-growing turfgrasses has been proposed to reduce mowing requirements. Traditional recommendations for home lawns are to mow by the "one-third rule" and return grass clippings. However, their impact on annual mowing requirements remains largely unknown. This study aimed to determine (i) the number of required mowing events when mowing weekly versus using the one-third rule; (ii) the influence of returning grass clippings on mowing requirements, dry matter yield (DMY), and leaf tissue N (LTN); and (iii) how turfgrasses with differing growth rates influence mowing requirements, DMY, and LTN. The one-third rule decreased mowing requirements by 31% (approximately eight mowing events yr-1) and returning grass clippings added approximately two additional mowing events yr-1. Tall fescue [Schedonorus arundinaceus (Schreb.) Durmort., nom. cons.; Festuca arundinacea Schreb.] required more annual mowing events than Kentucky bluegrass (Poa pratensis L.)(nine and three more in 2012 and 2013, respectively). Tall fescue had a greater 2-yr cumulative DMY than Kentucky bluegrass (875 vs. 522 g m-2). Growth rate (i.e., cultivar) also affected annual mowing requirements and yield: the faster the growth rate, the more annual mowing events. Leaf tissue N concentrations were higher when clippings were returned and with slower-growing cultivars. Mowing by the one-third rule and selecting slower-growing cultivars of turfgrass species adapted to a particular location can reduce annual mowing requirements and subsequent mower emissions. [ABSTRACT FROM AUTHOR]

Didymodon liae J. Kou, X.-M. Shao & C. Feng sp. nov., is described and illustrated from Dagzê County in south central Tibet, China. The new species is most similar to Didymodon australasiae (Hook. & Grev.) R. H. Zander, but differs in plants growing loosely in a thin turf, stems without hyalodermis and sclerodermis, margins recurved from just above the base nearly to the apex, laminal cells strongly bulging, mammillose, covered with simple or forked papillae, and costa with a layer of ventral substereids. The new species is contrasted with other similar species of the genus. Information on its distribution and ecology is also provided. [ABSTRACT FROM AUTHOR]

There is a widely-held belief in the turfgrass industry that irrigating with water high in bicarbonate will result in carbonate accumulation in the soil, despite a lack of evidence for this claim. While water quality problems are traditionally associated with arid regions, water quality recommendations are being applied to more humid regions where there is a lack of research to correlate water chemistry with soil properties. The objective of this study was to investigate the relationships among soil properties, climate, and irrigation water quality for golf courses across the United States. This study examines the vertical distribution of soil inorganic carbon (SIC) in 28 sand putting green soils across a range of geographic locations and climates. Soils below a pH of 7.8 had very little inorganic carbon, and soils above this pH had variable levels of inorganic carbon. There was no relationship between SIC and the estimated bicarbonate load from irrigation water, mean annual precipitation (MAP), or annual potential evapotranspiration (ETp). Our findings from this study do not provide evidence that bicarbonate from irrigation will cause formation of layers or zones of accumulation in putting green soils, contrary to this widely-held belief in the turfgrass industry. [ABSTRACT FROM AUTHOR]

The recommended N rates for St. Augustinegrass (Stenotaphrum secundatum [Walt.] Kuntze.) vary in Florida. This research, conducted in Fort Lauderdale, Citra, and Jay, FL, (20062008), aimed to determine the minimum N rate necessary for acceptable St. Augustinegrass and to determine the influence of N and irrigation rate on NO3-N leaching. Urea was applied in Fort Lauderdale, Citra, and Jay at 98, 196, 294, and 588; 49, 196, 343, and 490; and 49, 98, 196, and 294 kg N ha-1 yr-1, respectively, based on best management practices. Irrigation was 2.5 mm d-1 and 13.0 mm three times weekly in Fort Lauderdale; 13 mm twice weekly and 26 mm wk-1 in Citra and Jay. In Fort Lauderdale and Jay, lower than recommended N rates mostly produced acceptable turfgrass. Applications of 196 kg N ha-1 (Fort Lauderdale) and 98 kg N ha-1 (Jay) were the lowest rates producing acceptable turf. In Citra, 65% more N was required for acceptable turf than the recommended minimum . Leaching from all N rates was similar, except when N rates exceeded recommendations or when turfgrass exhibited herbicide stress. The high irrigation rate doubled NO3-N leaching compared to the low rate in Fort Lauderdale; irrigation frequency had no influence on leaching in Citra or Jay. The predicted minimum N rate for acceptable turf in Fort Lauderdale was <98 kg N ha-1 yr-1 (lower than in Citra; more than in Jay). In stressed turf, additional N conferred little benefit to quality and increased leaching. [ABSTRACT FROM AUTHOR]

Core Ideas: More information is needed to improve late‐season bermudagrass control strategies in the Central Plains region of the United States.A single autumn application of glyphosate reduces bermudagrass cover the following spring.Bermudagrass control with a single autumn application of glyphosate was not improved by adding fluazifop, mesotrione, or both. Multiple summer applications of glyphosate (N‐(phosphonomethyl)glycine) are commonly recommended for bermudagrass (Cynodon spp.) control. However, this regime results in an extended period of displeasing and nonfunctional turfgrass, and is not ideal for spring establishment. An autumn glyphosate application prior to winter dormancy can control bermudagrass and may benefit spring establishment projects. However, research is needed to more precisely define the parameters of efficacious late‐season herbicide applications for bermudagrass control as it transitions into dormancy. Therefore, our objective was to examine late‐season bermudagrass removal using combinations of glyphosate, fluazifop‐p‐butyl (fluazifop) (Butyl (R)‐2‐[4[[5‐(trifluoromethyl)‐2‐pyridinyl]oxy]phenoxy]propanoate), and mesotrione (2‐(4‐methylsulfonyl‐2‐nitrobenzoyl)‐1,3‐cyclohexanedione). Experiments were initiated in October 2013 at the Rocky Ford Turfgrass Research Center in Manhattan, KS, on mature 'Midlawn' hybrid bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt‐Davy], and at Stagg Hill Golf Course in Manhattan, KS, on mature common bermudagrass [C. dactylon (L.) Pers.]. Seven herbicide treatments containing combinations of glyphosate, fluazifop, and mesotrione were evaluated. Green bermudagrass cover (0–100%) was visually estimated when treatments were applied and every 14 d after application. Only treatments containing glyphosate reduced the green cover of bermudagrass at each site the following year. Across all ratings dates and locations, adding mesotrione, fluazifop, or both to glyphosate did not further reduce green bermudagrass cover. Overall, results indicate that a single autumn application of glyphosate prior to bermudagrass dormancy reduces bermudagrass cover the following spring. The significant reduction at spring green‐up may allow turf managers to make additional applications in the spring for increased control before spring establishment. [ABSTRACT FROM AUTHOR]

Core Ideas: Backtrack mowing produced the fastest green speeds compared with all other treatments.Shortening the clip of the reel or mowing in multiple directions removes more sand topdressing than standard mowing practices.Mowing patterns or clip of the reel had no visual effect on plant health. [ABSTRACT FROM AUTHOR]

Core Ideas: Many postemergence herbicides can be safely applied during buffalograss greenup in early to mid‐April (0% greenup) with little chance of turf damage.Herbicide that does not contain 2,4‐D can be safely applied during buffalograss greenup until 1 June (70‐85% greenup).Herbicide containing 2,4‐D should be applied before the first week of May (10‐15% greenup) for turf safety concerns, or apply no later than third week of May (50‐60% greenup) for acceptable stand during the summer months. [ABSTRACT FROM AUTHOR]

Species-rich semi-natural grasslands in Europe are becoming more fragmented and many species that depend on this habitat type are rare and threatened today. Management methods like mowing and grazing are needed to preserve remaining grasslands. Because management is costly it is important to use the most cost-effective as well as the most beneficial management method, but few studies have compared mowing and grazing. We investigated the effect of mowing and grazing on grassland vegetation using data from 11 long-term field trials situated in southern Sweden. We calculated the change in the odds of finding species belonging to three different groups of indicators at the start of the treatment and after 8 and 14 years. The used indicator groups were indicators of good management, excess nitrogen and poor management. The results revealed an increase in the odds of finding indicators of good management in mowed plots and an increase in finding indicators of excess nitrogen in grazed plots. The odds of finding indicators of poor management remained unchanged. Results from sub-analysis of the grazing intensity showed a more negative effect from grazing with low grazing intensity than normal/high grazing intensity. Therefore, mowing is the best long-term management method for seminatural grasslands in Sweden and grazing using a low grazing intensity should be avoided. [ABSTRACT FROM AUTHOR]

An increasing amount of reclaimed water is being used in turfgrass management; however, reclaimed water is often high in total dissolved salts and can result in salt stress injury and poor turf quality. The objectives of this study were to (i) determine the broad-sense heritability estimate of salinity tolerance of 142 perennial ryegrass (Lolium perenne L.) genotypes and (ii) determine narrow-sense heritability estimates and evaluate inheritance characteristics of salinity tolerance (heterosis, maternal effects, and combining ability) of progeny from crosses between fixed resistant and susceptible clones. Six replicates of each clone were irrigated overhead with a salt solution and were rated visually for percentage green color. The broad-sense heritability estimate for salinity tolerance was 0.78, indicating that the majority of the phenotypic variation was due to genetic effects. A diallel cross between three salt-tolerant and three salt-sensitive parents was performed in 2006. Parents and progeny were established, irrigated overhead with a salt solution, and visually rated for percentage green in 2007 and 2008. Narrow- sense heritability ranged from 0.72 (2007) to 0.66 (2008), indicating that the majority of the phenotypic variation was due to additive gene effects. No heterosis or maternal effects were found and general combining ability (GCA) accounted for more variance than specific combining ability (SCA). These results support the finding that salinity tolerance in perennial ryegrass is strongly controlled by additive gene effects. These data support a recurrent selection program that concentrates additive alleles as an effective breeding strategy to improve salinity tolerance in perennial ryegrass. [ABSTRACT FROM AUTHOR]

Turf managers often rely on fungicides to limit damage caused by root diseases. Because fungicides are applied to aboveground surfaces and do not move basipetally, they are effective against root pathogens only when fungitoxic concentrations migrate to the rhizosphere. This research focused on the distribution of modern fungicides in verdure, thatch, sand, and roots of creeping bentgrass [Agrostis stolonifera L. var. palustris (Huds.) Farw.] maintained as a putting green. The fungicides azoxystrobin (methyl (E)-2-[2-[6-(2-cyanophenoxy)pyrimidin-4- yloxy]phenyl]-3-methoxyacrylate), propiconazole (1,2,4-triazole, 1-((2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-yl)methyl), pyraclostrobin (carbamic acid, [2-[[[1-(4-chlorophenyl)-1 H- pyrazol-3-yl]oxy]methyl]phenyl]methoxy-,methylester), and thiophanate-methyl (dimethyl 4,'4-o-phenylenebis[3-thioallophanate]) were applied to replicate field plots in a water volume of 815 L ha-1. Plots were sampled at 0, 3, 7, 10, 14, 17, and 21 d after application by extracting cores measuring 1.9 cm in diameter by 3.8 cm deep. Cores were separated into verdure/ thatch, sand, and roots before quantitative determination (liquid chromatography, triple quadrupole mass spectrometry) of fungicide residues. Fungicide residues in verdure/thatch declined steadily with time and support previously reported results describing fungicide depletion. Fungicides were detected in roots and sand within 5 h of application at very low (1-15 mg kg-1) concentrations and remained at low levels throughout the sampling period. Fungicides differed with respect to amounts recovered per turfgrass component. Azoxystrobin and propiconazole were associated with roots for the duration of the experiment, but pyraclostrobin was nearly undetectable. Near-zero levels of all fungicides were detected in the sand component. Half-life values in the verdure/thatch component ranged from 2.3 to 18.9 d. [ABSTRACT FROM AUTHOR]

The need for water conservation in urban landscapes requires research to investigate alternative irrigation methods that are more efficient than overhead sprinkler systems. A study was conducted in 2009 at New Mexico State University in Las Cruces, and was repeated in 2013 at the University of California, Riverside, to compare the establishment of bermudagrass [Cynodon dactylon (L.) 'Princess 77'] and seashore paspalum [Paspalum vaginatum (Sw.) 'Sea Spray'] seeded on either 15 April or 15 May and irrigated at 100% reference evapotranspiration (ETos) with either an overhead sprinkler (OSI) or subsurface drip irrigation (SDI) system. Higher germination rates were observed at both locations when OSI was used. All treatments reached full ground cover by the end of the growing season in California, whereas SDI plots seeded in May in New Mexico reached only 75% ground cover. May seeding resulted in slower establishment in New Mexico with 147 d to reach 75% ground cover, but not in California. Results suggest that loss of water by deep percolation may be the cause of slower establishment with SDI in New Mexico. Based on our results, warm-season turfgrasses should be established earlier in the season if SDI is used in light textured soils. [ABSTRACT FROM AUTHOR]

Large herbivores play a key role in creating spatial heterogeneity through the formation of grazing lawns. Recent research suggests that the currently accepted nutrient-based theory on the formation of these grazing lawns cannot universally explain their formation in all ecosystems where they are found., We developed and investigated an alternative hypothesis on grazing lawn formation and maintenance based on herbivore effects on the plant-soil water balance. We propose that large herbivores change the soil water balance in grazing lawns through defoliation and soil compaction, causing a shift in vegetation composition towards a drought-tolerant plant community., Investigating this idea in a tropical savanna, we indeed found profound differences in grazing lawn soil properties and water balance. In particular, defoliation increased soil temperatures and potential evaporation rates while soil compaction increased bulk density and decreased water infiltration rates, especially on fine-textured soils. Soil moisture was therefore generally much lower in grazing lawns than in adjacent bunch grass areas., Furthermore, we found that grazing lawn species show drought-tolerant traits, with higher leaf sodium levels, suggesting evolutionary adaptation to these herbivore-induced dry conditions. However, leaf water potentials did not differ between grazing lawn and bunch grass species., Synthesis. This study shows that large herbivores might form grazing lawns through previously underestimated effects on water balance. Thus, future studies on large herbivore effects on vegetation should increasingly focus on additional pathways of soil compaction and defoliation. While nutrient-based processes driving grazing lawn formation may operate during the wet season in savannas, we suggest that water balance-based processes are additionally important during the dry season. [ABSTRACT FROM AUTHOR]

Organic matter buildup in the form of thatch or mat layers leads to several problems in turfgrass management systems. In a previous greenhouse study, laccase enzyme solution reduced the rate of accumulation of organic matter when applied at an activity level of 2.0 units cm-2 every 2 wk for 9 mo on 'Crenshaw' creeping bentgrass (Agrostis stolonifera L.). A 2-yr field experiment was conducted on creeping bentgrass to optimize the laccase activity level, frequency of application, and to determine potential interactions with core aeration and topdressing cultural practices. Laccase enzyme at five activity levels, 0, 0.5, 1.0, 2.0, and 4.0 units cm-2, was applied every 2 wk. The frequency of laccase application was tested using a laccase activity level of 2.0 units cm-2 applied at frequencies of 2, 4, 8, or 12 wk. The common cultural management practices of core aeration and sand topdressing were compared with and without laccase enzyme at an activity level of 2.0 units cm-2 applied once a month. Results indicated that laccase treatments were effective in reducing thatch layer thickness (TLT) at rates as low as 0.5 units cm-2 applied every 2 wk and as infrequent as once a month when applied at a rate of 2.0 units cm-2. Laccase application at 2.0 units cm-2 once in 4 wk was just as effective at reducing TLT as was core aeration and sand topdressing twice per year. Even greater reductions in TLT were observed when laccase was applied in combination with core aeration and sand topdressing. [ABSTRACT FROM AUTHOR]

Sports fields have evolved in design, construction, and maintenance toward complex multiuse venues that host several different types of events. Low-end sports fields such as public fields, parks, and recreation fields often suffer from limited care and excessive wear. High-end fields suffer from problems of an altered microenvironment due to modern trends in high-capacity stadia designs and from increasing wear caused by nonsporting and sporting events. Regardless, sports fields must obey a determined sport's regulations, offering adequate playability and providing a safe playing surface for the players. An aesthetically well-presented sports field can also enhance the game experience for both players and viewers. Interactions between sports fields, players, and the ball are key to safety and playability. Such interactions are influenced by field construction, turfgrass choice, and maintenance practices. Poor quality sports fields can impair playability and increase injury potential, especially knee anterior cruciate ligament injuries, one of the most common injuries in sports. This review provides a compilation of research techniques attempting to quantify sports turf playability: wear and wear simulation, ball rebound resilience, coefficient of restitution, ball roll, spin and friction, friction and traction, and surface hardness; their relationship with player safety; and, finally, we present new ideas on the future and improvement of sports turf research. [ABSTRACT FROM AUTHOR]

Mixtures of turfgrass species are commonly used throughout the world when establishing cool-season grasses from seed. However, there have been limited studies investigating how various species compete with each other as the turf matures. A study was conducted in Padova, Italy, to investigate the performance and species composition of four mixtures that contained a single cultivar of Kentucky bluegrass (KB; Poa pratensis L.) and two rhizomatous or two nonrhizomatous tall fescue (TF; Festuca arundinacea Schreb.) cultivars. The trial was seeded in September 2010. Three mowing heights (20, 32, and 62 mm) were also applied to all the mixtures. General turfgrass performance of the mixtures was monitored through the 2011 growing season, and species composition was measured regularly to determine the abundance of both species in the mixture. Throughout the study, the mixtures containing the rhizomatous TF consistently had higher turfgrass quality and turfgrass density than mixtures containing the nonrhizomatous types. Mowing height had less effect on the performance of the mixtures, but the lower mowing heights (20 and 32 mm) performed more consistently than the plots mowed at the highest (62 mm) mowing height. Species composition of the mixtures was significantly influenced by the different TF cultivars, in that KB was less abundant in mixtures containing rhizomatous TF cultivars compared to nonrhizomatous cultivars, suggesting an increased competitive ability of rhizomatous TF lines. Mowing height also influenced the species composition, in that KB was significantly more abundant at lower mowing heights. [ABSTRACT FROM AUTHOR]

Maintaining a mixture of cool- and warm-season turfgrasses year-round instead of overseeding into a perennial monoculture stand annually in the transition zone may be an effective way to combine the strengths of two species. Four mixtures of tall fescue (Festuca arundinacea L.) (Jaguar 3 and Bonsai) and zoysiagrass (Zoysia japonica Steud.) (Zenith and Cathy) were evaluated under 5- and 7.5-cm mowing heights and N regimes of 400, 200, and 100 kg ha-1 yr-1 in Beijing, China, during 2011 and 2012. Turf quality was better at a 5-cm mowing height than a 7.5 -cm mowing height in July and October and was equivalent between the two mowing heights for the other months. Visual quality was highest in plots receiving N at 400 kg ha-1 yr-1 in May, June, September, October, and November. In August, however, the highest visual turf quality was observed for an N rate of 100 kg ha-1 yr-1. Generally, the 5-cm mowing height and low N application produced high shoot density and ground coverage by zoysiagrass, whereas the shoot density of tall fescue showed no difference between the two mowing heights. The higher N rate most often favored greater tall fescue shoot density and ground coverage. Based on the results, we recommend a 5-cm mowing height and an N rate of 400 kg ha-1 yr-1, avoiding application in August, for the mixture. [ABSTRACT FROM AUTHOR]

The ability of researchers to accurately assess the extent of impervious and pervious developed surfaces, e.g., turf grass, using land-cover data derived from Landsat satellite imagery in the Chesapeake Bay watershed is limited due to the resolution of the data and systematic discrepancies between developed land-cover classes, surface mines, forests, and farmlands. Estimates of impervious surface and turf grass area in the Mid-Atlantic, United States that were based on 2006 Landsat-derived land-cover data were substantially lower than estimates based on more authoritative and independent sources. New estimates of impervious surfaces and turf grass area derived using land-cover data combined with ancillary information on roads, housing units, surface mines, and sampled estimates of road width and residential impervious area were up to 57 and 45% higher than estimates based strictly on land-cover data. These new estimates closely approximate estimates derived from authoritative and independent sources in developed counties. [ABSTRACT FROM AUTHOR]