Turf Grass Research Articles

Rusty blackbird patch use during winter in suburban landscapes

ABSTRACTThe rusty blackbird (Euphagus carolinus) is a species of conservation concern throughout its range because of rapid population decline. During winter, relatively large flocks are in suburban landscapes within the Georgia and South Carolina Piedmont Plateau of the southeastern United States. We studied radio‐tagged blackbirds within flocks that moved daily among 3 distinct patch types: pecan (Carya illinoinensis) and small‐seeded oak (Quercus spp.) groves, shallowly flooded forested wetlands, and residential areas landscaped with turf grass. The patch types used for foraging have varying availability of invertebrate and mast food. We investigated the relationship between daily observations of blackbird flocks and previous, current, and oncoming short‐term weather. Suburban landscapes with the appropriate configuration of shallow wetland, residential lawns, and mast grove patches within a 153–415‐ha area, the size of patch aggregations in this study, likely constitute high quality wintering areas for this species. Blackbird flocks were 1.6–1.8 times more likely to be observed foraging in wetlands with each 10°C increase in current temperature, 1.5 times more likely in wetlands for every 5 days with no previous precipitation, and 3.2 times more likely in wetlands with every 10 extra hours of oncoming cold weather. Blackbirds were 4.1–4.5 times less likely to be observed foraging in forested wetlands with every 5‐mm increase in current precipitation. Blackbirds were 2.2 times more likely to be observed in mast groves with every 5‐mm of oncoming precipitation. Radio‐tagged blackbirds used pecan groves for foraging in 2011 but not 2012, which was an overall warmer winter. Pecan groves may be a sporadically used component of a combination of foraging patches that are rarely near flooded forested wetlands or residential areas. Our results can be used to identify and conserve patch components used by rusty blackbird flocks during winter in suburban nature parks and greenways. © 2018 The Wildlife Society.

Autonomous Rotary Mower versus Ordinary Reel Mower—Effects of Cutting Height and Nitrogen Rate on Manila Grass Turf Quality

High-quality sports turfs often require low mowing and frequent maintenance. Sports turfs often consist of hard-to-mow warm season turfgrasses, such as zoysiagrass (Zoysia sp.) or bermudagrass (Cynodon sp.). Although autonomous mowers have several advantages over manually operated mowers, they are not designed to mow lower than 2.0 cm and are consequently not used on high-quality sports turfs. All autonomous mowers are only equipped with rotary mowing devices and do not perform clipping removal. An ordinary autonomous mower was modified to obtain a prototype autonomous mower cutting at a low height. The prototype autonomous mower was tested on a manila grass (Zoysia matrella) turf and compared its performance in terms of turf quality and energy consumption with an ordinary autonomous mower and with a gasoline reel mower. A three-way factor experimental design with three replications was adopted. Factor A consisted of four nitrogen rates (0, 50, 100, and 150 kg·ha−1), factor B consisted of two mowing systems (autonomous mower vs. walk-behind gasoline reel mower with no clipping removal), and factor C consisted of two mowing heights (1.2 and 3.6 cm). Prototype autonomous mower performed mowing at 1.2-cm mowing height whereas ordinary autonomous mower mowed at 3.6-cm mowing height. The interaction between the mowing system and mowing height showed that the turf quality was higher when the turf was mowed by the autonomous mower and at 1.2 cm than at 3.6 cm. Autonomous mowing not only reduced the mowing quality, but also reduced the leaf width. Lower mowing height induced thinner leaves. Nitrogen fertilization not only increased the overall turf quality, reduced weed cover percentage, but also reduced mowing quality. Autonomous mowers also had a lower energy consumption if compared with the reel mower (1.86 vs. 5.37 kWh/week at 1.2-cm mowing height and 1.79 vs. 2.32 kWh/week at 3.6-cm mowing height, respectively). These results show that autonomous mowers can perform low mowing even on tough-to-mow turfgrass species. They could also be used on high-quality sports turfs, thus saving time as well as reducing noise and pollution.

Improving quality of Bermuda Grass (Cynodondactylon var. Evergreen) by adding of bentonite to growing media and proper irrigation frequency

Generally sand is used as root zone of turf grass in golf course. High permeability of sand caused irrigation inefficient. This research was conducted to find the effect of addition of bentonite and frequency of irrigation to improve qualities of Bermuda grass (Cynodondactylon var evergreen). Experiments using factorial completely randomized design with two treatment factors with 3 replications. The first factor was the addition of bentonite 25 mesh which consisted of three levels i.e. 100% sand, 87.5% sand + 12.5% bentonite, and 75% sand + 25% bentonite. The second factor was the frequency of irrigation which consisted of three levels i.e. every day, every two days, every three days. Results of research showed interaction of media mix and the irrigation frequency was significantly affected all variable of grass qualities. Mix of sand 87.5% + bentonite 12.5% with watering of once every two days produced the best visual quality, and functional quality at the height of grass, clipping dry weight, shoot dry weight, as well as on the efficiency of irrigation water use (EIWU). It is recommended to use mix of sand 87.5% + bentonite 12.5 % with every two days watering that generally produced the best qualities and spends water consumption.

Field Evaluation of Some Microbial and Chemical Insecticides in Controlling Pachyzancla licarsicalis (Walk.) Lepidoptera: Pyralidae on Paspalum vagenatom Turf grass

Insecticides; Lanet, Chlorofos and microbial insecticide Bacillus thuringiensis (Dipel 2X) at the recommended rates of application were evaluated for controlling on the larvae of Pachyzancla licarsicalis (Walk.) infesting Paspalum Vagenatom turf grass. Efficacy of different compound on the larvae of P. licarsicalis infesting P. Vagenatom turf grass. The data present indicated obviously the effectiveness of the used chemical insecticides (Lanet, Chlorofos) and microbial insecticide (Dipel 2X) on the population density reduction of P. licarsicalis Larvae on P. Vagenatom turf grass. Treatments were applied 5 times at Nasr City – Cairo Governorate during 2017 season and 5 times also in Smart Village at 6 October City – Giza Governorate during the same season 2017 to induce a perfect control of the P. licarsicalis and protect the plants for longer periods. Lanet was the most effective insecticide, recording the highest reduction percentages in Nasr City after 21 days and in Smart Village after 21 days post-initial application too (76.56 and 83.81%, respectively). Also in both Nasr City Cairo Governorate and Smart Village Giza Governorate Dipel was the least tested recording reduction percentages (58.33% and 78.75%), respectively after 21 days of the application. All compounds were differed significantly than control and not exhibited any phytotoxicity on P. Vagenatom leaves.

Molecular cloning and sequence variance analysis of the TEOSINTE BRANCHED1 (TB1) gene in bermudagrass [Cynodon dactylon (L.) Pers

TEOSINTE BRANCHED1 (TB1) encodes a TEOSINTE BRANCHED1, CYCLOIDEA, and PROLIFERATING CELL FACTOR (TCP) transcription factor that represses axillary bud outgrowth and lateral branch formation in plants. Previous studies have elucidated the essential tillering regulatory roles of TB1 in many grasses, including maize and rice; however, the functions of TB1 in turf grasses remain unclear. In this study, we cloned the CdTB1 gene from bermudagrass, an important turfgrass species, and characterized the transactivation function of the CdTB1 protein. Sequencing the CdTB1 gene locus in a mini-core germplasm collection of Chinese bermudagrasses led to the successful identification of 66 SNP and 2 indel mutations in the protein-coding region as well as 28 SNP and 11 indel mutations in the promoter region. Interestingly, mutations in the C-terminal transactivation domain of the CdTB1 protein had no significant influence on the transactivation activity, whereas a novel 335-bp insertion mutation located in the promoter region could significantly increase the expression of the CdTB1 gene. Furthermore, wild accessions of bermudagrass harboring the novel insertion mutation were found to have significantly reduced tillers compared with other accessions, suggesting a negative correlation between the mutation and tillering. The results of this study not only expanded our knowledge of TB1 gene expression regulation but also provided possible molecular markers to breed cultivars of turf and forage grasses with specific architectural features.

The effect of grass endophytes on earthworms and slugs under a turf mowing regime

Earthworms are not a direct pest of turf grass but they are considered a problem on many sports fields, disrupting playability and aesthetics due to the castings they deposit on the playing surface. Also, a number of slug species are well-known foliage destroying pests of a number of agriculturally important crop species. Perennial ryegrass and tall fescue cultivars associated with selected Epichloë endophytes, originally developed for bird management at airports, were assessed to determine their deterrent properties towards worms and slugs. Plots sown with endophyte-free ryegrass had significantly higher numbers of worms and slugs than plots containing the same grass cultivar infected with the endophyte strain AR95. Also, plots sown with endophyte-free tall fescue had significantly higher numbers of slugs (but not worms) than plots containing the same grass cultivar infected with the endophyte strain AR601. Although more research is required on the exact mechanism of action, these results suggest selected novel endophyte-infected grass associations, such as those including the endophyte AR95, may substantially reduce populations of worms and slugs in areas where these grasses are sown.

Gross primary productivity of a large metropolitan region in midsummer using high spatial resolution satellite imagery

Although gross primary productivity (GPP) is estimated with remote sensing over large regions of Earth, urban areas are usually excluded due to the lack of light use efficiency (LUE) parameters for urban vegetation and the spatial heterogeneity of urban land cover. Here, we estimated midsummer GPP, both within and among vegetation and land-use types, across the Minneapolis-Saint Paul, Minnesota metropolitan region. We derived LUE parameters for urban vegetation types using estimates of GPP from tree sap flow and eddy covariance CO2 flux observations, and from fraction of absorbed photosynthetically active radiation based on 2 m resolution WorldView-2 satellite imagery. Mean GPP per unit land area (including vegetation, impervious surfaces, and soil) was 2.64 g C m−2 d−1, and was 4.45 g C m−2 d−1 per unit vegetated area. Mapped GPP estimates were within 11.4% of estimates from independent tall tower eddy covariance measurements. Turf grass GPP had a larger coefficient of variation (0.18) than other vegetation classes (~0.10). Vegetation composition was largely consistent across the study area. Excluding golf courses, mean land-use GPP for the total study area varied more by percent vegetation cover (R2 = 0.98, p < 0.001) than by variability within vegetation classes (R2 = 0.21, p = 0.19). Urban GPP in general was less than half that of natural forests and grasslands in the same climate zone.

The Fungal EndophyteEpichloë festucaevar.loliiDoes Not Improve the Freezing Tolerance of Perennial Ryegrass

A lack of winter hardiness limits the utility of perennial ryegrass (Lolium perenneL.) as a turf and forage grass in northern latitudes. The fungal endophyteEpichloë festucaevar.loliiis commonly associated with perennial ryegrass and is believed to enhance stress tolerance in some environments. The effect ofE. festucaevar.loliion freezing tolerance was assessed using seven diverse perennial ryegrass entries. Freezing tolerance was used as a proxy for winter hardiness, and most entries had been previously field tested to confirm this supposition. Three experiments were designed to isolate the effect of the endophyte from confounding effects from the grass host and the endophyte removal process. Experiment 1 compared hosts with (E+) or without (E−) endophytes that were either genetically identical or non‐isogenic, but from the same entry. Isogenic E+ and E− plants did not differ in freezing tolerance; however, some non‐isogenic populations differed in freezing tolerance. Experiment 2 used additional populations of non‐isogenic hosts to confirm the association between freezing tolerant hosts and endophyte infection. Isogenic hosts were polycrossed and the half‐sib E+ and E− progeny were used in Exp. 3, eliminating any effect of the endophyte removal process. Freezing tolerance did not vary between related families differing in endophyte infection, confirming that highly related hosts were not affected by endophyte. These results strongly suggest that nativeE. festucaevar.loliihas no direct effect on freezing tolerance but may be found in higher frequencies in freezing‐tolerant hosts.

Above-ground carbon dynamics in different arid urban green spaces

Urban areas are proven sources of anthropogenic carbon dioxide (CO2) emissions, but urban greenery offers an opportunity to mitigate climate change impacts. Satellite remote sensing is valuable tool in assessing current and historical carbon stock dynamics. In this study, we estimated above-ground carbon (AGC) stock within four land use types including parks and gardens, avenue plantations, open greenery and institutional greenery in selected locations in Muscat Governorate through field measurement and satellite applications. Five different estimated spectral vegetative indices (VIs) acquired from Landsat 8 OLI were employed to develop linear and non-linear regression models between the spectral vegetative indices and the AGC stocks. The model with the highest coefficient of determination was used to estimate the AGC of the entire selected locations in Muscat Governorate for the year 2014 and 2017. The study results showed that both normalized differential vegetation index (NDVI) and ratio vegetative index correlate strongly with AGC in Parks and gardens with NDVI showing moderate correlation with AGC in Avenue plantations. The AGC in CO2 equivalence in Muscat Governorate, Oman, for 2014 and 2017 were estimated to be 5987 and 9591 tons, respectively, with an annual sequestration rate of 1201 tons. The social value of the current CO2 equivalent storage for 2017 was US $ 537,127.00 (OMR 206,802.85). Background turf grass and impervious surfaces might have affected the AGC–VIs correlations within the land use types. Urban greening projects involving plantation of high biomass trees may enhance urban carbon sequestrations.

INFLUENCE OF COMPOST, MINERAL AND EFFECTIVE MICROORGANISMS APPLICATION ON SANDY SOIL-GROWN BERMUDA TURFGRASS

Two field experiments were conducted during 2016 and 2017 seasons at the Experimental Farm, Fac. Agric., Minia Univ. to study the effect of compost, mineral NPK and/or Effective microorganisms (E.M.) on the performance and chemical constituents of bermuda grass grown in sandy soil. Obtained results revealed that compost, especially when added at the high level (22.5 ton/fed), as well as, 75 % NPK + E.M. caused considerable increase in all studied vegetative growth characters, as well as, the three photosynthetic pigments and N, P and K %. However, the high compost level (22.5 ton/fed) in combination with the dual fertilization treatment (75 % NPK + E.M.) resulted in the highest overall grown and the best performance of bermuda turf grass grown in sandy soil.

Transcriptome analysis providing novel insights for Cd-resistant tall fescue responses to Cd stress

Cadmium (Cd) is a severely toxic heavy metal and environmental pollutant. Tall fescue is a cold season turf grass which has high resistance to Cd as well as the ability to enrich it. To investigate the molecular mechanism underlying the adaptability of tall fescue to Cd stress, RNA-Seq was used to examine Cd stress responses of tall fescue at a transcriptional level. A total of 12 cDNA libraries were constructed from the total RNA of roots or leaves of tall fescue with or without Cd treatments. A total of 2594 (1768 up- and 826 down-regulated) differentially expressed genes (DEGs) were detected in the roots of Cd-stressed tall fescue compared with control roots (R_cd vs R_ck), while only 52 (29 up- and 23 down-regulated) DEGs were found in the leaves of Cd-stressed plants versus the controls (L_cd vs L_ck). The genes encoding glutathione S-transferase (GST), transporter proteins including the ABC transporter, ZRT/IRT-like protein, potassium transporter/channel, nitrate transporter, putative iron-phytosiderophore transporter, copper-transporting ATPase or transporter and multidrug and toxic compound extrusion (MATE) proteins, and numerous transcription factors were found to be significantly induced in Cd-treated roots. In addition, pathogenesis/disease-related gene mRNAs were accumulated in Cd-treated roots of tall fescue. Furthermore, the significantly enriched KEGG pathways in roots were related to ‘Glutathione metabolism’, ‘Ribosome’, ‘alpha-Linolenic acid metabolism’, ‘Diterpenoid biosynthesis’, ‘Sulfur metabolism’, ‘Phenylpropanoid biosynthesis’, ‘Protein processing in endoplasmic reticulum’, ‘Protein export’ and ‘Nitrogen metabolism’. The study provides novel insights for further understanding the molecular mechanisms of tall fescue responses to Cd stress.

Factors influencing agricultural spray deposit structures on hydrophobic surfaces

The properties of dried deposits formed by placing drops of a commercial turf grass fungicide spray formulation on smooth, waxy PARAFILM® M surfaces were measured as functions of formulation variables. The deposit structure reveals the extent to which dispersed active ingredient particles are bound to oil droplets in agricultural spray dispersions, before drying. The dilute spray dispersion (herein called Green Emulsion) was a suspoemulsion, which is a mixed dispersion of large (2–50 μm) mineral oil drops and small (∼430 nm) polychlorinated Cu (II) phthalocyanine (PG7) pigments, also known as Green 7. The distribution of PG7 pigment in the dried spray drop deposit depended upon the partitioning of PG particles in the suspension before drying. Individually dispersed PG7 particles in the aqueous phase mainly ended up in the annulus (coffee ring), whereas PG7 particles adsorbed on the oil emulsion droplets ended up as a central oily deposit (the dome). After most of the water evaporated, some oil migrated beyond the dome and slowly beyond the annulus. Increasing the oil-soluble surfactant concentration inhibited PG7 binding to the oil/water interface, giving a very small dome area and a wide annulus after drying. The deposit structure is sensitive to the mixing intensity when spray concentrates are diluted in a mix-tank. Increased intensity of mixing the suspoemulsion gives smaller oil droplets, more PG7 bound to the oil/water interface and a smaller dome. The ASTM E2044 “Standard Test Method for Spreading of Liquid Agricultural Spray Mixtures” involves placing a drop of crop spray dispersion on PARAFILM® and measuring the dimensions of the resulting sessile drop. This work demonstrates that allowing the sessile drops on PARAFILM® to dry and analyzing the resulting deposit structure gives a direct measure of the extent to which active ingredient particles, initially dispersed in water, are transferred on or into oil drops in suspoemulsions.

Effect of pre and post emergence herbicides for weed management in bermuda grass (Cynodon dactylon) var. Tif dwarf 419

Turf grasses are the plants which form a continuous ground cover and is the assurance of a lush, high-quality lawn but the presence of weeds during green establishment can reduce growth and turf quality. Field experiment was conducted to investigate efficacy of Pendimethalin (1.0 kg a.i./ha) – pre emergence, Atrazine (1.0 kg a.i./ha) - pre emergence, Carfentrazone (30 g/ha)- post emergence (40 DAS), Metribuzin (300 g/ha) - pre emergence, Pendimethalin (0.75 kg/ha) + Metribuzin- pre emergence, Pendimethalin (Pre emergence) + Carfentrazone- (Post emergence), Pendimethalin (Pre emergence) + Metribuzin (Post emergence), Atrazine (Pre emergence) + Carfentrazone (Post emergence), Atrazine (Pre emergence) + Metribuzin (Post emergence), manual weeding (four hand weeding) on the establishment of Tif dwarf 419 Bermuda grass from sprigs. The results suggest that application of Pendimethalin @ 0.75 l/ha (pre-emergence) + Carfentrazone @ 0.0225 kg/ha (post-mergence) at 40 days after sowing was effective for controlling the weeds followed by Atrazine @ 0.75 l/ha (pre-emergence) + Carfentrazone @ 0.0225 kg/ha (postemergence) at 40 days after sowing. Carfentrazone (30g/ha) alone as post emergence herbicide recorded about 75% weed mortality.

Incidence and Severity of Game-Related College Football Thoracoabdominal Injuries on Artificial versus Natural Grass

In the past, serious injuries have been attributed to playing on artificial turf. Newer generations of artificial turf, however, have been developed to duplicate the playing characteristics of natural grass. No long-term studies have compared articular and muscle trauma of the thoracoabdominal region between the two surfaces. PURPOSE: To quantify incidence and severity of game-related thoracoabdominal collegiate football injuries on artificial turf vs natural grass. METHODS: A total of 24 universities were evaluated over 8 competitive seasons for injury incidence rates (IIRs) across injury severity, injury category, injury mechanism and situation, primary type of injury, anatomical location, type of tissue injured, elective imaging and surgical procedures, and turf age. RESULTS: Of the 1,237 collegiate games documented, 628 (50.8%) were played on artificial turf vs 609 (49.2%) played on natural grass. A total of 379 thoracoabdominal injuries were reported with 147 (38.8%) occurring on artificial turf, and 232 (61.2%) on natural grass. MANOVAs per 10 games indicated a significant playing surface effect by injury severity (F2,379 = 7.505; P = .001), primary type of injury (F12,379 = 4.412; P = .000), tissue type (F3,379 = 9.412; P = .000), elective imaging and surgical procedures (F3,379 = 3.517; P = .007), and turf age (F2,379 = 91.093; P = .000), but not by injury category (F3,379 = 2.175; P = .089), injury mechanism (F3,379 = 1.439; P = .133), or injury situation (F8,379 = 1.329; P = .181). Univariate analyses indicated significantly lower (P = .05 - .0001) IIRs across severity, both in 1st degree, 2.1 (95% CI, 1.8-2.5) vs 2.9 (2.5-3.2), and 2nd degree IIRs, 0.1 (95% CI, 0.1-0.2) vs 0.7 (0.5-0.9); defensive positions, 0.8 (95% CI, 0.6-1.1) vs 1.4 (1.2-1.7); contusions, 1.3 (95% CI, 1.1-1.6) vs 2.0 (1.7-2.3); muscle, 2.0 (95% CI, 1.7-2.3) vs 3.0 (2.6-3.4); MRI, 0.1 (95% CI, 0.0-0.2) vs 0.2 (0.1-0.4); and turf lasting 4-7 years, 0.8 (95% CI, 0.6-1.1) vs 0.9 (0.7-1.2), and 8+ years 0.1 (95% CI, 0.1-0.2) vs 0.5 (0.4-0.8) when comparing artificial turf vs natural grass, respectively. CONCLUSION: Since minimal differences existed between artificial turf and natural grass over an 8-year period of competitive play, artificial turf is a practical alternative when comparing thoracoabdominal injuries in collegiate football.

Incidence and Severity of College Football Hand and Wrist Injuries on Artificial versus Natural Grass

Over the past two decades, newer generations of artificial turf have been developed to duplicate the playing characteristics of natural grass. Few turf-related studies have been published comparing hand and wrist trauma. PURPOSE: To quantify incidence and severity of game-related collegiate football hand and wrist injuries on artificial turf vs natural grass. METHODS: 24 universities were evaluated over 8 competitive seasons for injury incidence rates (IIRs) across injury severity, injury category, injury mechanism and situation, primary type of injury, anatomical location, type of tissue injured, elective imaging/surgery, field conditions, and turf age. RESULTS: Of the 1,237 collegiate games documented, 628 (50.8%) were played on artificial turf vs 609 (49.2%) played on natural grass. A total of 536 hand and wrist injuries were reported with 212 (39.6%) occurring on artificial turf, and 324 (60.4%) on natural grass. MANOVAs (Wilks’ λ) indicated a significant playing surface effect by injury severity (F2,533 = 8.053; P < .0001), primary type of injury (F11,524 = 5.254; P < .0001), body part injured (F4,531 = 3.294; P = .006), tissue type (F3,532 = 12.421; P < .0001), elective imaging/surgery (F4,531 = 2.798; P = .039), field conditions (F3,532 = 13.991; P < .0001) and turf age (F3,532 = 90.901; P < .0001), but not by injury category, position played, injury mechanism, or situation. Post hoc analyses indicated significantly lower IIRs (P < .05 to .0001) observed across 2nd degree trauma, 0.2 (95% CI, 0.1-0.3) vs 0.6 (0.4-0.8); ligament sprains, 1.4 (95% CI, 1.2-1.7) vs 2.0 (1.7-2.3), and subluxations, 0.4 (95% CI, 0.3-0.6) vs 0.3 (0.3-0.5); joint, 2.1 (95% CI, 1.8-2.4) vs 2.5 (2.2-2.9), and muscle trauma, 0.6 (95% CI, 0.5-0.9) vs 2.0 (1.7-2.3); MRIs, 0.0 (95% CI, 0.0-0.1) vs 0.2 (0.1-0.3), and x-rays ordered, 1.7 (95% CI, 1.4-2.0) vs 2.2 (1.8-2.5); during adverse weather conditions, 0.3 (95% CI, 0.2-0.6) vs 1.2 (0.8-1.6); and turf lasting 4-7 yrs, 0.9 (95% CI, 0.7-1.2) vs 1.3 (1.1-1.6), and 8+ yrs, 0.1 (95% CI, 0.1-0.2) vs 0.8 (0.7-1.1) when comparing artificial turf to natural grass, respectively. CONCLUSION: Although similarities existed between both surfaces over an 8-year period of competitive play, artificial turf is in many cases safer than natural grass when comparing hand and wrist trauma in college football.

Quantifying Water and Energy Fluxes Over Different Urban Land Covers in Phoenix, Arizona

AbstractThe impact of urbanization on water and energy fluxes varies according to the characteristics of the urban patch type. Nevertheless, urban flux observations are limited, particularly in arid climates, given the wide variety of land cover present in cities. To help address this need, a mobile eddy covariance tower was deployed at three locations in Phoenix, Arizona, to sample the surface energy balance at a parking lot, a xeric landscaping (irrigated trees with gravel) and a mesic landscaping (irrigated turf grass). These deployments were compared to a stationary eddy covariance tower in a suburban neighborhood. A comparison of the observations revealed key differences between the mobile and reference sites tied to the urban land cover within the measurement footprints. For instance, the net radiation varied substantially among the sites in manners consistent with albedo and shallow soil temperature differences. The partitioning of available energy between sensible and latent heat fluxes was modulated strongly by the presence of outdoor water use, with the irrigated turf grass exhibiting the highest evaporative fraction. At this site, we identified a lack of sensitivity of turbulent flux partitioning to precipitation events, which suggests that frequent outdoor water use removes water limitations in an arid climate, thus leading to mesic conditions. Other urban land covers with less irrigation, however, exhibited sensitivity to the occurrence of precipitation, as expected for an arid climate. As a result, quantifying the frequency and magnitude of outdoor water use is critical for understanding evapotranspiration losses in arid urban areas.

Longevity, growth and community ecology of invasive Poa annua across environmental gradients in the subantarctic

Poa annua is a cosmopolitan weed in turf grass. It is a widespread non-native species in the subantarctic and also occurs in the Antarctic Peninsula. It has highly variable morphology, longevity and reproductive capacity across both its invaded and native range. Little is known about the ecology of P. annua in the subantarctic, particularly its longevity, morphological variation across small spatial scales and competitive ability. We monitored individual P. annua plants on subantarctic Macquarie Island to assess their longevity; quantified morphology and biomass allocation across environmental gradients; and assessed community diversity indices in areas of varying P. annua density. We show that P. annua plants on Macquarie Island are perennial, and their morphology varies with elevation, animal disturbance and soil properties. At low altitude, coastal sites with high animal disturbance and deep, sandy soils, P. annua plants are larger and native plant diversity is low. Conversely, at high altitude sites P. annua plants are smaller and the diversity of native species is not reduced. This new information informs why P. annua is the most successful plant invader in the subantarctic and quantifies some key characteristics enabling an invasive species to function well beyond its natural range. Community ecology theory can also explain patterns in the ecology of P. annua on Macquarie Island.

Effect of Aeration and Compaction on Some Characters Of a Turf Grass Mixture Under Sulamani City Conditions

Effect of Aeration and Compaction on Some Characters Of a Turf Grass Mixture Under Sulamani City Conditions

SPOROBOLUS SPICATUS, A POTENTIAL TURF GRASS UNDER THE CLIMATIC CONDITIONS OF UAE

Different accessions of Sporobolus spicatus were tested for the possible use in the landscaping sector of United Arab Emirates. In this regards, fifty accessions of S. spicatus were screened against five salinity levels of 15, 30, 45, 60 and 75dSm-1 at 3cm mowing height. Significant variations were found among the treatment for various characters of leaf colour, fresh and dry weight. Most of the accessions of the grass tolerated up to 45 dSm-1, without compromising on quality. Further increase in salinity, most of the accessions ceased to grow, except a few accessions which survived even at salinity levels of 75dSm-1. Many of the grasses exhibit better performance than Paspalam vaginatum, the prevailing commercial turf grass in UAE (used as control in this instance). As a whole accessions 45S, 18S, 35S and 37S showed salinity tolerance at 3cm mowing height and maintaining quality up to the acceptable level. Based on their tolerance to salinity and better performance, these accessions are recommended for turf use in public landscaping.

Phoma macrostoma : as a broad spectrum bioherbicide for turf grass and agricultural applications.

Abstract Phoma macrostoma Montagne 94-44B is an effective bioherbicide for broadleaved weed reduction. In 2016, Health Canada's Pest Management Regulatory Agency (PMRA), under the authority of the Pest Control Products Act and Regulations, granted full registration for the sale and use of the bioherbicide P. macrostoma Montagne 94-44B to control a broad spectrum of broadleaf weeds in established turfgrass and new seeding of grasses as well as in field grown nursery plants, trees and container-grown ornamentals. P. macrostoma 94-44B colonizes susceptible and non-susceptible plant roots, however, only in susceptible plants, such as Taraxacum officinale (dandelion), do mycelium proliferate around the vascular trachea interfering with the function of neighbouring cells while not entering them. Macrocidins, secondary metabolites secreted by P. macrostoma 94-44B mycelia, inhibit multiple steps in carotenoid precursor formation including phytoene desaturase and steps associated with β carotene and lutein carotenoid biogenesis, Fe and Mg chelation and OJIP chlorophyll fluorescence, thus uncoupling the light-harvesting complex of photosystem II from the reaction centre. The combined actions of P. macrostoma 94-44B and macrocidins elicit photobleaching of the leaves and eventual weed death. Research is underway to exploit Phoma's bioherbicidal actions for weed management in agriculture. P. macrostoma 94-44B can be used to reduce broadleaved weeds in crops such as wheat, corn, potato, forage grasses and established alfalfa (2nd growth or older). Soil residue studies reveal that neither P. macrostoma 94-44B nor macrocidins are present after 1 year suggesting that farmers could plant Phoma -sensitive crops such as legumes, flax or canola in subsequent years.