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Turfgrass Recovery after an Induced Drought Period on a Golf Course Fairway: Case Study in Southern Spain
Abstract
The water management of golf courses is an issue of concern in drought-prone areas that demand irrigation strategies aimed at reducing turfgrass water consumption. Deficit irrigation and summer drought are water-saving strategies that are being assessed at a research level to cope with water shortages. In this work, the response of Cynodon dactylon (L.) var. Riviera to an induced period of severe summer drought of around 75 days and the subsequent recovery was assessed at a golf course in southern Spain. The green cover (GC) fraction and the main turf quality attributes were compared during two drought/recovery cycles to well-watered turfgrass. The results show that the deficit irrigation applied before the drought period decreased the quality of the turfgrass and led to fast turfgrass quality impairment during the drought interval, reaching the lowest quality level around 40 days after the beginning of the drought period. Once irrigation recovery started, GC and turf quality levels similar to those observed before the deficit irrigation period were reached after 30 days. Also, this water management strategy was effective for the control of weeds, especially Digitaria spp.
... In this sense, some experiments have proved their ability to recover after a total absence of water supply during a certain summer period (Croce et al., 2004;Geren et al., 2009;Severmutlu et al., 2011;Steinke et al., 2011). This is particularly important in order to optimize available water resources under conditions of severe scarcity, since irrigation could be suppressed in some parts of the golf courses during the summer months, sometimes coinciding with off-season periods (Monje- Jiménez et al., 2019), prioritizing areas such as greens and tees (Gross, 2013). In these cases, the turfgrass will remain inactive until the arrival of rainfall events in autumn or irrigation is resumed, which will facilitate its recovery. ...
... In our study, different plots were selected for each year of study, so we cannot draw conclusions about the cumulative effects of water stress. Nevertheless, in a recent study carried out in the same area (Monje- Jiménez et al., 2019), it has been observed that the application of summer drought periods for successive years did not result in losses of bermuda recovery capacity to drought once irrigation was resumed. ...
Water management constitutes one of the main challenges for turfgrass growing in arid and semi-arid regions, exacerbated when the conditions under which the turfgrass is cultivated are limiting (e.g., sandy shallow soils with low maintenance). The objective of this study has been to evaluate the recovery of Tifway [Cynodon dactylon (L.) Pers. × Cynodon transvaalensis (Burtt-Davy)] bermudagrass when grown on a 10-cm sandy soil rootzone and under low-maintenance management (i.e., reduced fertilization) after varying periods of summer drought. Turfgrass assessment was performed by monitoring the green coverage and quality attributes during the recovery period. The duration of the drought was found to be determinant for the recovery capacity of Tifway bermudagrass. Summer drought periods longer than 5 weeks did not allow reaching at least 50% of the green coverage. The soil depth and type were shown to be limiting factors of the recovery capacity from drought of Tifway bermudagrass, as can be seen from a comparison with other data found in the literature for the same species/cultivar. The data collected in order to monitor the performance of the turfgrass (green cover and visual quality) using Digital Image Analysis and Normalized Difference Vegetation Index were very similar to those obtained by traditional observation methods, reducing labor hours.
Water restrictions on irrigation are rarely science-based and may cause irreversible damage to turfgrass or inadvertently waste water. Our objectives were to evaluate effects of minimum water applications to 'Meyer' Japanese lawngrass (Zoysia japonica Steud.) on: 1) canopy performance during prolonged drought and; 2) survival and recovery thereafter. Meyer was watered with 0 to 30% reference evapotranspiration (ETo) replacement for two months in two consecutive summers under a rainout shelter near Manhattan, KS. Soil moisture and canopy performance [normalized difference vegetation index (NDVI), percent green cover (PGC), and turfgrass quality] were measured weekly. Results indicated 20 to 30% ETo slowed the decline in canopy performance compared with no water inputs. Irrigation at 30% ETo maintained Meyer at >75 PGC throughout the first year, but even Meyer at 0 and 5% ETo recovered after full irrigation resumed. In the second year, 30% ETo maintained Meyer at >25 PGC throughout the drought and recovered thereafter, but plots with 0 and 5% ETo only recovered to 30-42 PGC after 50 d of full irrigation. Reducing irrigation from the recommended 60% ETo for warm-season turfgrasses to 30% ETo saved 9-11 cm of water; further reductions to 20% ETo saved another 3-4 cm during the 2-month droughts with insignificant additional PGC reductions (<18%). Water restrictions during severe droughts such as limiting weekly irrigation of Meyer Japanese lawngrass to 20-30% ETo could reduce turfgrass damage and conserve water.
Water restrictions may be imposed on irrigation during drought with little regard for damage to turfgrass. Minimal irrigation that may result in dormancy during prolonged drought but allows for recovery thereafter may save water and prevent expensive reestablishment. Our objectives were to: 1) determine minimum water amounts in turfgrass during drought that allow for acceptable recovery; and 2) evaluate turfgrass quality and performance during drought and recovery among irrigation levels. Sodded ‘Seed Research 8650’ tall fescue (TF, Schedonorus arundinaceus Schreb.) and a ‘Mallard’ and ‘Ridgeline’ Kentucky bluegrass blend (KB, Poa pratensis L.) were watered with 0-50% reference evapotranspiration (ETo) replacement during two summers under rainout shelters near Manhattan, KS. Soil moisture, percentage green cover, normalized difference vegetation index, and turfgrass quality were measured weekly. After fall sodding, TF recovered fully after 60-83 d dry downs in both years even without water inputs. However, KB in all ETo treatments did not recover in either year. Irrigation at 50% ETo maintained TF above minimally acceptable quality 15-43 d longer than 0% ETo during drought, recovered 17-18 d faster, and reduced water inputs by 38% compared with 80% ETo, which is usually recommended for well-watered TF. Results indicate TF is better adapted than KB to prolonged drought in the first summer after fall sodding.
Irrigation of residential and commercial lawns in excess of plant water requirements can result in waste of potable water supply and negative public perception regarding turf landscapes. A 3-year field study was conducted to evaluate simple historical ETo-based irrigation scheduling for maintenance of St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze ‘Raleigh’] lawns in College Station, TX, USA. Whole main plots were assigned crop coefficients of 1.00, 0.60, 0.36, or 0.24 (K100, K60, K36, and K24) used to adjust historical ETo (47-year average). Sub-plots received N rates of either 0.0, 0.4, or 0.8 kg ha⁻¹ month⁻¹ during the experimental period each year. Irrigation treatments were applied 3 days per week from July through September each year. Acceptable turf quality was maintained when irrigation depths were ≥47% of actual ETo. The K60 treatment provided adequate irrigation for turf performance but caused 31% overwatering in the wettest year. The K36 treatment resulted in acceptable turf quality not only in the wettest year, but also showed complete recovery of the turf sward by the end of fall in each year. This research has outlined a simple and effective method for conserving water used to irrigate St. Augustinegrass lawns.
There is a dearth of information about turfgrass drought resistance and adaptation in theMediterranean region of Turkey. Turfgrass managers in this region need this information to help them make informed decisions regarding turfgrass selection and management. This research was conducted to assess the drought resistance of bermudagrass (Cynodon dactylon), buffalograss (Buchloe dactyloides), bahiagrass (Paspalum notatum), seashore paspalum (Paspalum vaginatum), zoysiagrass (Zoysia japonica), centipedegrass (Eremochloa ophiuroides), and tall fescue (Lolium arundinaceum) under Mediterranean conditions of Turkey. The study was conducted at two locations, Antalya andMersin, and was repeated in 2006 and 2007 at both locations. One year after establishment, the turfs were subjected to drought stress for 90 days, which was followed by resumption of irrigation for recovery of the turf. Percentage leaf firing, turfgrass quality, and percent green shoot recovery were recorded. There were inter and intraspecies differences detected for percentage leaf firing and shoot recovery. Bermudagrass, bahiagrass, and buffalograss exhibited superior drought resistance as demonstrated by lower leaf firing and better shoot recovery values when compared with other species studied. Centipedegrass and zoysiagrass demonstrated a high leaf firing and very poor shoot recovery, whereas zoysiagrass and tall fescue were unable to recover fromthe drought stress in the sandy soil. Results showed that 'SWI-1045' (Contessa®) and 'SWI-1044' bermudagrass and 'Cody' buffalograss possessed superior drought resistance with acceptable turfgrass quality up to 30 days under drought stress that can be used for waterefficient turf management under the Mediterranean environment.
Turfgrass performance can be assessed in terms of visual quality, but evaluators require training and may be distracted by many factors that affect accuracy and consistency. The objectives of this study were to assess a handheld optical sensor (GreenSeeker) for evaluating overall turfgrass quality in three turf species over two growing seasons, and to compare the combined time required for visual evaluation and data entry with the time required for the same functions using the handheld optical sensor. Visual quality ratings and sensor ratings were collected on schedules prescribed by the National Turfgrass Evaluation Program for the 2002 bermudagrass (Cynodon spp.), 2002 buffalograss (Buchloe dactyloides), and 2002 zoysiagrass (Zoysia spp.) studies in 2003 and 2004. Use of the sensor reduced the time required to complete data collection and data entry by 58% compared with human visual evaluation. Of the three species tested, the bermudagrass evaluation had the strongest correlation between ratings collected by the human evaluator and the sensor [r = 0.79 in 2003 (n = 343), r = 0.85 in 2004 (n = 343)]. The handheld optical sensor provided a consistent, objective evaluation of overall turfgrass quality and required less time than visual evaluation. The handheld optical sensor provides advantages for assessing turfgrass quality that cannot be realized by human evaluation, but the sensor alone is not sufficient for specific evaluations such as color, texture, or density that are routinely characterized by human evaluation.
En este artículo, se exponen las medidas que se adoptan en el diseño del sistema de riego y drenaje en campos de golf, los criterios para la mejora en los consumos de agua, los usos del agua para golf en las políticas autonómicas, las ventajas del agua reutilizada y ejemplos de su uso. También se analizan las actuaciones referentes al consumo de agua recogidas en el Protocolo Q-Plus de Campos de Golf, concebido como una marca de garantía basada en un proceso de certificación objetiva e independiente.
Digital image analysis (DIA) provides an accurate, nondestructive, and objective assessment of turf color. Previous research developed an index known as the dark green color index (DGCI) via DIA as an indicator of turf color. The objective of this study was to use DGCI variability to better predict a visual rating (VR) index used to evaluate tall fescue (Festuca arundinacea Schreb.) color under different irrigation treatments. To develop DGCI statistics, two freeware software packages (ImageJ and R) were used to extract and process information from digital images. The model to predict VR from DIA was developed and calibrated using candidate DGCI statistical moments from 120 images in a calibration data set using a multiple linear regression procedure. Fitness of calibration and validation models were verified using the adjusted coefficient of determination, root mean square error, and the Mallow's C p statistic. The two-variable model produced more precise estimates (adjusted R2 = 0.926 and 0.899) than the model that only used one term in predicting the VR values (adjusted R2 = 0.879 and 0.843) for calibration and validation sets, respectively. These data suggest incorporating a measure of color uniformity improves the use of DGCI in predicting VR values compared to using only the mean of DGCI values to predict VR values. Model refinements may be needed for other turf species, but current work suggests using additional statistical moments such as SD improves VR estimate precision and accuracy.
The objective of this study was to determine physiological traits for drought survival and post-drought recovery upon re-watering in two C3 perennial grass species, kentucky bluegrass [KBG (Poa pratensis)] and perennial ryegrass [PRG (Lolium perenne)]. Plants were maintained well watered or exposed to drought stress by withholding irrigation and were then re-watered in a growth chamber. KBG had significantly higher grass quality and leaf photochemical efficiency, and lower electrolyte leakage than PRG during 20 days of drought. After 7 days of re- watering, drought-damaged leaves were rehydrated to the control level in KBG, but could not fully recover in PRG.KBG produced a greater number of new roots, while PRG had more rapid elongation of new roots after 16 days of re- watering. Superior drought tolerance in KBG was associated with osmotic adjustment, higher cell wall elasticity, and lower relative water content at zero turgor. Osmotic adjustment, cell wall elasticity, and cell membrane stability could play important roles in leaf desiccation tolerance and drought survival in perennial grass species. In addition, post- drought recovery of leaf hydration level and physiological activity could be associated with the accumulation of carbohydrates in leaves and rhizomes during drought stress and new root production after re-watering.
Turf quality (TQ) decline due to drought is a major concern in cool-season turfgrass management. The study was conducted to examine whether selected Texas (TBG) x Kentucky bluegrass (KBG) hybrids (HBGs) (Poa arachnifera Tort. x P. pratensis L.) exhibit improved drought stress tolerance and recuperative ability in comparison to commonly-used KBG (P. pratensis) genotypes. Plant material included two HBG selections (HBG568 and HBG668), two commercially-available HBGs ('Thermal Blue' and 'Bandera'), and two KBG genotypes ('Midnight' and 'Baron'). The experiment was conducted in field plots covered with a rainout shelter in 2006 and 2007 in North Brunswick, NJ. Treatments consisted of (i) well-watered controls; (ii) drought stress (withholding irrigation) from June to August; and (iii) recovery (rewatering after a period of drought stress) in September and October. The HBGs Thermal Blue and Bandera generally did not show significant difference in turf growth from the two KBG genotypes in both years. HBG568 maintained significantly higher TQ relative water content (RWC), cell membrane stability, and canopy density estimated as the reflectance ratio of infrared to red (IR/R, leaf area index) and normalized difference vegetation index (NDVI), compared with the two KBG genotypes and other HBGs following a prolonged period of drought stress (after 20 d of treatment) on most sampling dates in both years. HBG568 exhibited more rapid recovery of TQ IR/R (IR935/R661), NDVI, and sod tensile strength than the other genotypes in both years, while HBG668 also had better recovery in 2007. The results demonstrate genetic variation in drought stress tolerance and recovery among HBGs and KBGs and the potential for the development of HBGs with improved tolerance to drought stress and performance during recovery.
High–quality turf demands high water and nutrient inputs, as well as intensive maintenance. Due to decreasing
water availability and high maintenance costs, efficient methods of water and fertilizer delivery and identification of site–specific management areas are required. In the turf industry and turf research, visual assessment has been used as the standard to evaluate turf response to management practices and treatments. This method is subject to bias due to personal perceptions and visual preferences. In addition, the cause of stress cannot be readily determined by visual inspection. In this research, multispectral radiometry was used as an alternative method of rating visual quality. The seasonal vegetation trend was observed using visual assessment and vegetation indices, response to nitrogen application, effect of mowing practice, and response to irrigation methods (subsurface drip irrigation and sprinkler irrigation) of bermudagrass turf were investigated. Vegetation indices (NDVI, RVI, and SDI) correlated well with visual quality ratings (r2 = 0.73, r2 = 0.71, and r2 = 0.70, respectively; P = 0.05). Mowing practice affected the spectral response in most wavelengths, increasing values
between 3% and 4% in the visible and mid–infrared ranges. Wavelengths in the near–infrared range were not affected. In contrast, values for vegetation indices decreased as a result of mowing practices.
Desde finales de la década de los años ochenta del siglo pasado hay una preocupación
generalizada por el impacto de los campos de golf sobre el medio ambiente. Varias
Comunidades Autónomas españolas han redactado una normativa que permite controlar la
incidencia de los campos de golf sobre dos aspectos fundamentales: las transformaciones
paisajísticas y la procedencia del agua consumida. Las evaluaciones de impacto ambiental
y el uso cada vez más generalizado de aguas depuradas contribuyen a minimizar los efectos
sobre el entorno de estas instalaciones, que constituyen una interesante oferta turística de
calidad sin estacionalidad.
Visual evaluation of turfgrass quality is a subjective process that requires experienced personnel. Optical sensing of plant reflectance provides objective, quantitative turf quality evaluation and requires no turf experience. This study was conducted to assess the accuracy of optical sensing for evaluating turf quality, to compare the rating consistency among human evaluators and optical sensing, and to develop a model that describes a relationship between optically sensed measurements and visual turf quality. Visual evaluations for turf color, texture, percent live cover (PLC), and optically sensed measurements were collected on the National Turfgrass Evaluation Program (NTEP) tall fescue (Festuca arundinacea Schreb) and creeping bentgrass (Agrostis palustris Huds.) trials at Stillwater, OK. Measurements were made monthly for 12 consecutive months from June 1999 through May 2000. Red (R) and near infrared (NIR) reflectance were collected with sensors and converted to normalized difference vegetative indices (NDVI). The NDVI were closely correlated with visual evaluations for turf color, moderately correlated with percent live cover (PLC), and independent of texture. Measurements of turf color and PLC were evaluated more consistently with optical sensors than by visual ratings. Normalized difference vegetation index (Y) could be reliably predicted by the following generalized model for turf color (X) and PLC (Z): Y = B(0) + B(1)log10X + B(2)Z(3). Optical sensing provided fast, reliable turf assessment and deserves consideration as a supplemental or replacement technique for evaluating turf quality.
Evaluation of turfgrass performance at low nitrogen fertility levels is important because many home lawns are fertilized below common recommendations. The objective of this study was to evaluate visible quality and weed susceptibility of common and alternative cool season grasses under multiple management regimes in Wisconsin. A split-split plot completely randomized block design was used to evaluate ‘Kingfisher' Kentucky bluegrass (Kentucky bluegrass), ‘Kenblue' Kentucky bluegrass, ‘Victory II' chewings fescue, ‘Grande II' tall fescue, and ‘Jiffe II' perennial ryegrass. Each species was mowed at 3.5, 6.0, or 8.5 cm, and fertilized with 0, 98, or 196 kg ha−1 yr−1 of nitrogen. Visible quality and weed cover were evaluated four times annually for 3 yr. Tall fescue had the greatest turf quality across all treatments. Kingfisher Kentucky bluegrass, an improved variety, responded most dramatically to nitrogen fertilization, with quality rating improved from 5.1 to 7.1 when annual nitrogen applications totaled 196 kg ha−1 compared to the nonfertilized control. Kenblue Kentucky bluegrass, a common variety, had the greatest weed cover at all mowing heights and fertilizer rates. Assessment of common dandelion flowers by digital image analysis revealed that improved and common Kentucky bluegrass had greater common dandelion cover than fine or tall fescue when herbicides were withheld for 2.5 yr. Background soil fertility was found to have a significant impact on visible quality and weed cover. In an area with eroded, low-fertility soil, improved Kentucky bluegrass required 196 kg N ha−1 yr−1 to maintain high quality and limit weed invasion. These results suggest that tall fescue is best suited to low and high input conditions, while improved varieties of Kentucky bluegrass performed acceptably only under high inputs.
Greenhouse studies were conducted on three warm-season turfgrasses, `Midlawn' bermudagrass [ Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt-Davy], `Prairie' buffalograss [ Buchloe dactyloides (Nutt.) Engelm.], and `Meyer' zoysiagrass ( Zoysia japonica Steud.), and a cool-season turfgrass, `Mustang' tall fescue ( Festuca arundinacea Schreb.) to determine 1) water relations and drought tolerance characteristics by subjecting container-grown grasses to drought and 2) potential relationships between osmotic adjustment (OA) and turf recovery after severe drought. Tall fescue was clipped at 6.3 cm once weekly, whereas warm-season grasses were clipped at 4.5 cm twice weekly. The threshold volumetric soil water content (SWC) at which a sharp decline in leaf water potential (ψ L ) occurred was higher for tall fescue than for warm-season grasses. Buffalograss exhibited the lowest and tall fescue exhibited the highest reduction in leaf pressure potential (ψ P ) per unit decline in ψ L during dry down. Ranking of grasses for magnitude of OA was buffalograss (0.84 MPa) = zoysiagrass (0.77 MPa) > bermudagrass (0.60 MPa) > tall fescue (0.34 MPa). Grass coverage 2 weeks after irrigation was resumed was correlated positively with magnitude of OA ( r = 0.66, P < 0.05).
Turf is an important component of the urban and rural landscape. The natural plant formations/biomes that it mimics are the tropical savanna, the temperate grasslands (steppe and the prairies) and the tundra. Turf in a higher or lower degree provides all the ecosystem services of the other types of vegetation. Vegetation ecosystem services that have been previously emphasized include functional, aesthetical, recreational, social, and economic services as well as services related to people psychological or physical health. The purpose of this review is to gather updated information on turf ecosystem services, mainly on how they compare to other types of vegetation, or substitutes, and to suggest some future trends/areas of research.
Turf has a unique role in aesthetics and, definitely, provides an irreplaceable surface for recreational sports/activities. From the available information, turf seems to have a higher potential than other types of vegetation for reducing runoff, increasing infiltration, purifying water from sediments and pollutants, controlling erosion, improving soil quality and reducing fire hazards. For the lawn owners the main turf benefits are: first the enhanced property aesthetics, second the increment in property value and third the provision of a recreation area. Turf, as all vegetation, uses water. Without the water its benefits may be reduced or annihilated. Mimicking nature may offer some solutions for saving water: summer brown lawns that green up in the fall, although losing some of the turf benefits, may be an appropriate choice where irrigation is not feasible and are worth some research. Research, should also be done on lawns using a mix of grasses and legumes: the presence of legumes may avoid N fertilization and, possibly allows for clippings removal and usage as biofuel, while keeping the soil accumulation of carbon, preventing N leaching and turning turf’s carbon footprint even more positive.
Postemergence herbicide options for mature goosegrass [Eleusine indica (L.) Gaertn.] control in bermudagrass (Cynodon spp. Rich.) turf are lacking. Greenhouse and field trials were conducted to determine the lowest rate at which topramezone, with or without triclopyr, controls goosegrass while maintaining acceptable bermudagrass quality. Greenhouse dose– response studies determined herbicide rates for field trials. In field trials, topramezone at 6.13 to 12.3 g a.i. ha⁻¹ applied twice at a 3-wk interval eliminated 8- to 18-tiller goosegrass at three of four locations. The same topramezone treatments did not reduce smooth crabgrass [Digitaria ischaemum (Schreb.) Schreb. ex Muhl.] cover more than 53% when applied alone and not more than 84% when applied with triclopyr at 140 g acid equivalent ha⁻¹. The number of days over a threshold of 30% injury or stunting (DOT30) within the 28-d period following each of two herbicide treatments was calculated for 31 bermudagrass varieties. Bermudagrass injury DOT30 following the first treatment ranged from 11.1 to 17.8 d, depending on variety. The addition of triclopyr increased injury DOT30 but reduced the severity of discoloration by eliminating white tissue discoloration. All varieties were severely injured but completely or near completely recovered by 28 d after each treatment. Generally, topramezone at 6.13 or 12.3 g a.i. ha⁻¹ applied twice controls goosegrass in bermudagrass. Addition of triclopyr improves smooth crabgrass control and decreases severity of bermudagrass injury but increases suprathreshold-injury duration.
Golf course water use continues to be highly scrutinized. Information is limited regarding minimal levels of reference evapotranspiration (ETo)-based irrigation needed to maintain adequate summer fairway performance and autumn recovery. The objectives of this 2-yr study were to (i) characterize ‘Tifway’ bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt Davy] fairway response to irrigation levels of 0.6, 0.45, 0.3, and 0.0 × ETo, with and without simulated summer traffic and (ii) evaluate effects of irrigation and traffic on autumn recovery at full irrigation levels. Without traffic, × 0.3 × ETo was generally adequate for maintaining acceptable quality both years. Withholding irrigation altogether resulted in unacceptable turf quality both years. Summer traffic reduced quality and percentage green cover at all irrigation levels. Canopy temperatures increased with diminishing irrigation, with up to 25×C difference between 0.6 × ETo and unirrigated plots. Upon resumption of full irrigation in autumn, deficit and unirrigated treatments rebounded to 80 to 90% green cover by late autumn. However, in Year 2, only irrigated plots recovered to adequate cover levels, with unirrigated plots suffering substantial injury with only 30% green cover by late autumn. While no rooting differences were detected in Year 1, turf the 0.3 × ETo and unirrigated treatments had lower root dry weights than 0.45 and 0.6 × ETo treatments in Year 2. These data suggest provision of minimal deficit irrigation levels during summer drought may be important for sustaining turf viability and promoting autumn recovery of bermudagrass following successive years of summer drought stress. © Crop Science Society of America | 5585 Guilford Rd., Madison, WI 53711 USA All rights reserved.
Municipalities often restrict irrigation of urban landscapes, causing plants to experience drought stress. Few data are available regarding drought resistance of non-turfgrass landscape species. This study evaluated the performance of one turfgrass (Poa pratensis L. 'Apollo') and eight herbaceous landscape species (Achillea millifolium L., Ajuga reptans L. 'Bronze Beauty', Liriope muscari Decne., Pachysandra terminalis Siebold and Zucc., Sedum album L., Thymus serpyllum L., Vinca major L., and Vinca minor L.) during a severe drydown and subsequent recovery. This greenhouse study was conducted in the spring/summer and again in the fall of 2010. S. album performed the best, averaging 254 days to decline to a drought rating of 1 (1 to 9 scale, 1 = dead/dormant and 9 = best quality). L. muscari and P. terminalis also performed well, averaging 86 days to a drought rating of 1. V. minor and V. major declined faster than the previous species, averaging 63 days. A. millifolium, A. reptans, P. pratensis, and T. serpyllum declined the fastest to a drought rating of 1 (mean 52 days). Thereafter, the only species to recover after 60 days of resuming irrigation were P. pratensis [46% pot cover (PC)], S. album (38% PC), and V. major (35% PC) in the spring/summer study; no species recovered during the fall study. Results indicate S. album, L. muscari, and P. terminalis are the most drought-resistant among the species evaluated in landscapes where severe drought may occur. V. minor and V. major are good selections in less severe droughts as is P. pratensis if periods of dormancy are acceptable.
Broad concerns over water shortages and drought where irrigated urban landscapes are common in high desert regions have focused attention on drought tolerance of turfgrass species. We investigated the physiological responses of kentucky bluegrass (KBG) and tall fescue (TF) under a prolonged drought under high desert conditions. The experimental design was a split plot with three replicates. Two irrigation treatments as a whole plot-well-watered and no water-were applied to subplots of 'Midnight' KBG and 'Gazelle' TF. Stomatal conductance (g S), canopy temperature, and predawn leaf water potential were measured over two seasons. KBG g S and leaf water potential decreased faster and to a greater extent than TF in response to soil drying, and KBG was in complete dormancy and brown within 5 weeks after cessation of irrigation. By contrast, TF maintained a green canopy throughout the drought periods. In the no-water plots, TF appeared to consume water from the deepest measured soil profiles (80-to 100-cm depth), whereas KBG used most of the water in the 50- to 60-cm depths. When watered for recovery in late summer, KBG plots were mostly green within 3 weeks after rewatering. The surface temperature of the well-watered plots was 6-13 °C cooler than the no-water plots and TF showed 5-7 °C lower temperature than KBG in no-water plots. TF is suitable for deep soil, exploiting a larger volume of water to avoid drought, whereas KBG's rapid drought avoidance would likely perform better in shallow landscape soils under drought.
Municipal water restrictions have become commonplace throughout much of the southern United States. The objectives of this 2-yr study were to (i) determine supplemental irrigation requirements necessary for achieving acceptable quality in 15 zoysiagrass (Zoysia japonica and Zoysia matrella) and bermudagrass (Cynodon ssp.) cultivars when managed under a 2 d/wk irrigation frequency, (ii) determine the effects of mowing height on irrigation requirements, and (iii) evaluate root development differences between the species and cultivars at the completion of the study. A linear gradient irrigation system (LGIS) was used to provide an irrigation gradient across field plots. Plots were evaluated along the gradient six times over two summers to determine the level of supplemental irrigation, relative to reference evapotranspiration (ETo), necessary for maintaining acceptable visual quality. The fine-textured, sports-type bermudagrass cultivars required the least supplemental irrigation (similar to 10 to 15% x ETo) to maintain acceptable quality in the study. The medium-textured amenity bermudagrasses and Japanese lawngrass (Zoysia japonica Steud.) cultivars required similar but somewhat greater irrigation requirements (similar to 15 to 20% x ETo) than the fine-textured bermudagrasses. Manilagrass cultivars (Z. matrella) required the highest supplemental irrigation requirements (similar to 25 to 33% x ETo) for maintaining acceptable appearance within 2 d/wk irrigation regime. Mowing height did not consistently affect irrigation requirements for either group of bermudagrass but affected the Zoysia species differently. Tall mowing heights generally reduced irrigation requirements in Z. japonica but increased irrigation requirements for Z. matrella cultivars. While few intraspecific root development differences occurred within the 0 to 25 cm soil depth, Z. matrella root development was limited relative to bermudagrass and Z. japonica cultivars within deeper (25-50 cm) soil, which may have contributed to the higher irrigation requirements for the species. The results emphasize differences in supplemental irrigation levels needed for maintaining acceptable appearance among warm-season turfgrass species and cultivars during 2 d/wk irrigation.
Multispectral radiometry provides a method for assessing plant light reflectance in the visible and near-infrared ranges. Reflectance of narrow wavelength ranges as well as ratios of different ranges have been highly correlated with absorbency of photosynthetically active radiation, leaf area index (LAI), and plant response to stresses. The objectives of this research were to determine if data obtained by multispectral radiometry might accurately correlate with qualitative data (used as rapid estimates of color, density, and uniformity) typically used in turfgrass research. Furthermore, it was our objective to determine whether multispectral radiometry could discriminate between stressed and nonstressed turfgrass plots. This research was conducted in two consecutive trials during 1997 on seven seashore paspalum (Paspalum vaginatum Swartz) ecotypes and three hybrid bermudagrass (Cynodon dactylon L. x C. transvaalensis Burtt-Davy) cultivars established on a native Appling (clayey, kaolinitic, thermic Typic Kanhapludult) soil at the University of Georgia Experiment Station in Griffin, GA. Reflectance at 661 and 813 nm, as well as the ratios normalized difference vegetation index (NDVI, computed as R935 - R661/R935 + R661), infrared/red (IR/R) (LAI, computed as R935/ R661), Stress1 (R706/R760), and Stress2 (R706/R813) were highly correlated with visual turf quality, shoot density, and shoot tissue injury (STI) ratings, but not with shoot clipping growth. Regression analysis also indicated very strong associations with each of these qualitative variables, but not with shoot growth data. Additionally, spectral measurements at all wavelengths except 559 and 706 nm were able to consistently distinguish between wear-treated and untreated plots. This methodology may have applications in both turfgrass research and management to provide quantitative measures with physiological significance to traditional visual qualitative estimates of shoot aspects.
A study was conducted at New Mexico State University in Las Cruces, NM, from 2010 to 2012 to investigate the effects of deficit irrigation on bermudagrass (Cynodon dactylon L.) cultivar Princess 77 and seashore paspalum (Paspalum vaginatum Swartz) cultivar Sea Spray treated with either soil surfactants [Revolution (modified methyl capped block copolymer) or Dispatch (alkyl polyglucoside blended with a straight block copolymer)] or a plant growth regulator [Trinexapac-ethyl (TE); 4-(cyclopropylhydroxymethylene)-3,5-dioxocyclohexanecarboxylic acid]. Irrigation was applied daily at 50% reference evapotranspiration from either a sprinkler or a subsurface drip system with either potable (electrical conductivity [EC] = 0.6 dS m−1) or saline (2.3 dS m−1) water. Normalized Difference Vegetation Index (NDVI) and visual ratings were determined monthly to assess stand quality and turf stress. Princess 77 treated with TE showed the highest quality and the highest NDVI (0.655) on 10 out of 15 sampling dates. Positive effects of TE applications were also observed on Sea Spray quality, NDVI, and fall color retention. Subsurface drip irrigation resulted in higher quality and NDVI during the third year of the study when compared with sprinkler irrigation. Salinity buildup in the root zone did not negatively affect visual quality of the tested warm-season species. Generally, sprinkler irrigation system and turf treated with Revolution promoted higher water distribution uniformity (lower standard deviations) than the other treatments. Further research is needed to investigate if greater drought tolerance of subsurface drip–irrigated turf is the result of increased water-use efficiency due to altered root morphology.
The objectives of this investigation were to assess the genetic diversity in dehydration avoidance and drought resistance among genotypes of Cynodon and Zoysia species. The approach was to provide an environment that would maximise the rate of water stress in the shortest period of time. This was achieved with a specially constructed field site consisting of 100% sand extending uniformly through the root-zone depth. Turfed plugs of 100 mm in diameter were collected from mature stands of at least four years age and transplanted in a randomised block arrangement with four replications. Once the turfs were fully rooted, the irrigation was terminated and assessments made over a five-month period, during which there was no significant natural rainfall, but with the high evapotranspiration rates typical of College Station, Texas. Substantial genetic diversity in both dehydration avoidance and drought resistance was found among the twenty-six Cynodon genotypes, which encompassed fourteen C. dactylon and twelve C. dactylon x C. transvaalensis hybrids. Among the Cynodon genotypes, those with the shorter root systems tended to have poorer dehydration avoidance and drought resistance. In contrast, the genetic diversity in dehydration avoidance was much narrower among the nine Zoysia grasses, which included both matrella and japonica genotypes. The much poorer dehydration avoidance when compared to the Cynodon species, was attributed primarily to a very limited root system, plus a higher evapotranspiration rate. The Zoysia species had a much slower rate of wax formation over the stomata during progressive drought stress in comparison to the Cynodon species.
Drought responsive turfgrass cultivars are becoming increasingly important in water conservation. Eight cultivars of bermudagrass [Cynodon dactylon (L.) Pers.], one cultivar of buffalograss [Buchloe dactyloides (Nutt.) Engelm.], and two root-zone depths were evaluated for drought response and recovery during consecutive 60-d drought and 60-d recovery periods over 2 yr. Individual cultivar responses to drought and post-drought recovery time were quantified through digital image analysis as the number of days to decrease to or increase to 50% green ground cover, respectively. No grass survived the 60-d drought when planted on the restricted 10-cm soil depth in 2006 or 2007, while all entries survived when planted on the unrestricted native soil depth. Both study years provided unique conditions for investigating drought response as the mean time to reach 50% green ground cover differed by 17 d between the 2 yr of study. Some cultivars lost 50% green ground cover in 20 d while other cultivars lasted the entire 60-d drought period without losing 50% green ground cover. Post-drought turfgrass recovery responses differed by as much as 45 d in achieving 50% green ground cover. Documenting individual cultivar responses to drought and recovery may provide perspective on individual grass cultivars that may initiate poor irrigation management behavior due to early leaf firing as well as refine consumer expectations following drought conditions.
As a result of increasing demand for potable water, local and national initiatives to conserve municipal water supplies have been implemented. Many of these initiatives focus on reducing irrigation of turfgrass in urban landscapes and may totally ban irrigation during periods of severe water shortage. Proper selection of adapted turfgrass species and cultivars is vital to long-term water conservation initiatives. Turfgrasses that can survive and recover from extended hot and dry periods under limited to no irrigation would best meet water conservation objectives. The present study was conducted to evaluate the recuperative potential of transplanted plugs of 24 commonly grown cultivars of three warm-season turfgrass species after incremental increases in water stress imposed by withholding all water for up to 60 days. A 2-year field study was conducted consisting of eight blocks containing 25 plots each. Each block was planted with one plot each of eight cultivars of bermudagrass (Cynodon dactylon sp.), seven cultivars of st. augustinegrass (Stenotaphrum secundatum sp.), and nine cultivars of zoysiagrass (five of Zoysia japonica sp. and four of Zoysia matrella sp.). Four blocks were planted on native soil with no restriction to rooting, whereas the other four had an effective root zone of only 10 cm of soil. Cup cutter plugs were collected at predetermined intervals, transported to College Station, TX, replanted, and grown under well-watered conditions. Measurements of the lateral spread of the plugs were taken every 10 to 14 days for the first 60 to 70 days after planting (DAP). The lateral spread of plugs collected after 0 days of summer dry-down (DSD) was greatest for bermudagrass, intermediate for st. augustinegrass, and lowest for zoysiagrass. In most cases there were no consistent differences between cultivars within a species. All species grown on the 10-cm deep root zone were unable to survive the 60-day period without water and died within the first 40 days. For each species, lateral spread was increasingly delayed or reduced with increasing DSD. Although all three species grown on native soil were able to survive and recover from a 60-day period without water, the bermudagrass cultivars had the most rapid recovery rates measured as lateral spread of transplanted plugs.
The objectives of this paper were to (1) evaluate drought resistance of a large number of bermudagrass ecotypes collected from different climatic zones of regional Australia and compare their performance to commercial cultivars, (2) describe the mechanisms of drought resistance observed, and (3) investigate the relationship between geographic origins of the ecotypes and their drought resistance. Fifty-two genotypes of bermudagrass were evaluated in two field experiments using lysimeters 40 cm deep. The grasses were grown in well-watered conditions and then a drought treatment was imposed by withholding water and excluding rainfall using a portable rain-out shelter. Two criteria were used to select for drought resistance, i.e. survival period (SP), defined as the number of days after water was withheld to the stage when 100% leaf firing had occurred and Days50 defined as the days required to reach 50% green cover. These experiments suggested that genotypes with superior drought resistance had lower stomatal conductance in the earlier phases of the dry-down period as suggested by less water use and higher canopy temperature depression. Lower water use during the early stage of dry-down resulted in more soil available water at the end of the drought period to extend green-leaf cover. There was no correlation between root dry matter and survival period/Days50. We also found some ecotypes performed better in drought conditions than popular commercial cultivars. There was no relationship between drought resistance and geographic origins, suggesting that drought resistant ecotypes could be obtained from any climatic zone sampled in this study.
Knowledge of relative drought resistance is important for selecting turfgrasses that persist during drought stress. Seven of the most commonly used turfgrasses in the Piedmont region of the humid Southeastern USA were evaluated in a field study under edaphic stresses common to the region for drought resistance and spatial rooting responses as a component of drought avoidance. Grasses were 'Tifway' bermudagrass (Cynodon dactylon x C. transvaalensis) ; common bermudagrass [C. dactylon (L.) Pers.] ; 'Meyer' zoysiagrass (Zoysia japonica Steud.) ; common centipedegrass [Eremochloa ophiuroides (Munro.) Hack.] ; 'Raleigh' St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] ; and 'Rebel II' and 'Kentucky-31' tall fescue (Festuca arundinacea Schreb.). Grasses varied in drought resistance, as determined by wilt and leaf firing during dry-down periods, from very high (Tifway and common bermuda), high (Raleigh St. Augustine, common centipede), medium-high (Rebel II tall fescue), medium (K-31 tall fescue), and medium-low (Meyer zoysiagrass). High soil strength and acid soil complex stresses were present on the site. Under these stresses, deep rooting (20- to 60-cm zone) in late summer ranged from Tifway bermuda (best) > Rebel II tall fescue = common bermuda > K-31 tall fescue > Raleigh St. Augustine > common centipedegrass > Meyer zoysiagrass. Meyer produced only 4% of the root length density that Tifway did within this zone due to low genetic tolerance to the edaphic stresses. These results illustrate that genetic tolerance to edaphic stresses can markedly affect turfgrass rooting and drought resistance rankings. Plant breeders must give attention to edaphic stress tolerances if drought avoidance via roots is to be improved.
A 3-yr field study was conducted to determine the influence of N level (98 and 196 kg ha -1 yr -1 ), mowing height (3.2, 5.5, and 8.8 cm), and three herbicides on weed encroachment and overall quality of tall fescue Festuca arundinacea Schreb. cv. Rebel II. The major objective of this study was to identify cultural methods of excluding weed development in tall fescue. Dithiopyr [3, 5-pyridinedicarbothioic acid, 2-(difluoromethyl)-4-(2-methylpropyl)-6-(trifluoremethyl)-S, S-dimethylester] and pendimethalin [N-(1-ethylpropyl)-3, 4-dimethyl-2, 6-dinitrobenzenamine] were applied preemergence for smooth crabgrass [Digitaria ischaemum (Schreber) Schreber ex Muhlenb.] control, and fenoxaprop [(±)-2-[4-[(6-chloro-2-benzoxazolyl)oxy]- phenoxy] propanoic acid] was applied postemergence for crabgrass control (.)
The objective of this study was to assess canopy broadband spectral refl ectance for turfgrasses under drought stress. Optimum turf quality (TQ) and leaf fi ring (LF) models were developed and compared based on two, three, and fi ve wave- length bands. Sods of bermudagrass (Cynodon dactylon L. × C. transvaalensis Burtt-Davy), sea- shore paspalum (Paspalum vaginatum Swartz), zoysiagrass (Zoysia japonica Steud.), and St. Augustinegrass (Stenotaphrum secundatum (Walt.) Kuntze), and seeded tall fescue (Festuca arundinacea Schreb.) were used in this study with three cultivars each of bermudagrass, seashore paspalum, and tall fescue. Traditional vegetation indices (VIs) based on two bands within 660 to 950 nm were not as sensitive as three to fi ve broadband models using a wider band range of 660 to 1480 nm. Optimum models were cultivar specifi c models, even within a spe- cies. The broadband wavelength at R900 and R1200 should be considered in drought sensi- tive spectral models since they were most often observed and exhibited high partial R2 values. These results suggest that mobile broadband spectral devices to map turfgrass responses to drought stress would benefi t by the availability of three to fi ve broadbands that could be user selected for optimum, cultivar specifi c models.
The golf sector is a relatively new competitor for scarce freshwater resources in many countries. Golf courses are increasingly being required to implement best management practice programmes promoting efficient use of water. As part of these programmes, water audits are undertaken to diagnose the current performance of the golf course. Benchmarking, a systematic process for detecting inefficiencies based on comparisons between similar systems, is a potential tool for identifying and targeting problem areas. An existing benchmarking methodology developed by the International Programme for Technology and Research in Irrigation and Drainage for agricultural irrigation schemes has been adapted for evaluating golf course irrigation. The objectives of growing sports turf are very different from agricultural production systems, but the underlying ethos is directly comparable. Groups of indicators were developed in four domains: system operation, financial performance, productive efficiency and environmental issues. The methodology was applied as a case study to three courses in south-east Spain to test its usability and capability. The results showed that the use of standard indicators and benchmarking does help highlight areas of potential improvement, though the particular circumstances and location of each course must be taken into account when interpreting the results. A larger data set using the standardized indicators is now needed to make the methodology useful more widely.
In many countries where water resources are under stress, there is a perception that irrigating golf courses causes significant additional abstraction, and that this has major impacts on the environment and other abstractors, including irrigated agriculture. This paper provides a quantitative assessment of water use within the golf sector in Spain, and compares it with irrigated agriculture. It is based on literature review, a national survey of golf course irrigation practices, and a correlation of reported irrigation consumption against agroclimate. Using a geographical information system (GIS), the water consumption for all golf courses in Spain was modelled and mapped, and the total water consumption estimated.
Developing a drought-emergency plan
- Gross B. Y. P.
Turfgrass performance when under irrigated
- Meyer J. L.
Drought stress on turf
- Schmidt R. E.