The study was conducted in Riverside and San Luis Obispo, CA, USA, in 2015 to investigate the impact of various herbicides on Kurapia (Phyla nodiflora), a groundcover that is gaining popularity for its drought and salt tolerance. Fifteen different herbicides were evaluated when applied at 1, 6, and 12 weeks post planting to understand effects on the establishment of Kurapia plugs. Climate differences between the two study locations were observed, with Riverside being warmer and San Luis Obispo having higher humidity. Such variations influenced Kurapia’s response to the herbicides. Key findings indicated that preemergence herbicides like Barricade 65WG, Pennant Magnum, and Gallery SC were beneficial during Kurapia establishment, but other herbicides, such as Fusilade II and Lontrel, also showed limited to no disruption to Kurapia growth. Herbicides like Specticle FLO, Tribute Total, Celsius, Drive XLR8, and Turflon Ester Ultra were found to be mostly injurious to Kurapia during establishment. Climate conditions, especially temperature and humidity variations, play a crucial role in herbicide performance and should be considered during application to prevent adverse effects on this groundcover.

Breeding bermudagrass ( Cynodon spp.) involves creating progeny combining multiple desired traits from hybridization and ensuring their adaptation and performance to various environments through rigorous testing. Turfgrass breeding programs in the southern United States collaborated to breed new bermudagrass lines for drought resistance. Thus, the objectives of this study were to evaluate advanced bermudagrass lines and to characterize their genetic gain in performance traits, reliability, genotype-by-environment interaction (GEI), and stability. The study, encompassing 34 advanced lines and three standard cultivars planted in randomized complete block designs with three replications, was carried out at eight locations across the southern United States from 2020 to 2023. Experimental lines OSU2073, OSU2081, OSU2082, TifB20201, and TifB20205 showed improved drought response relative to the drought resistant cultivar TifTuf with significant genetic gain in the mega-environment (a group of locations that share similar environment conditions in which a crop has consistent performance across them) of Dallas, TX, and Stillwater, OK. Substantial GEIs were observed under drought stress across the southern United States. This study highlights the continuous genetic gain made in breeding efforts to improve drought resistance of bermudagrass and identifies new cultivar candidates for conserving irrigation water to the turf industry.

In turfgrass breeding, drought resistance is a primary trait for improvement due to scarcity and reduced quality of water for irrigation. Therefore, in 2010, the turfgrass breeding programs at six public universities joined efforts to address these challenges by cross evaluating breeding lines for the most economically significant warm-season turfgrass species in the southern United States through a United States Department of Agriculture-National Institute for Food and Agriculture Specialty Crop Research Initiative funded project. Three breeding cycles were associated with three completed (2010-2014, 2014-2019, and 2019-2024) collaborative grant projects, but the efficiency of this partnership in terms of gains from selection has not been measured. Our objectives were to (1) estimate the expected and realized genetic gain for drought resistance and turfgrass quality for three breeding cycles, (2) compare cultivars developed with support of the projects versus standard cultivars in a historical data analysis, and (3) compare genetic gain for traits assessed visually versus using small unmanned aircraft systems imagery, both in drought and non-drought environments. For these purposes, historical data were investigated with a retrospective analysis of project trials evaluated 2011-2024. Our findings for the realized genetic gain demonstrated progress in enhancing drought resistance in bermudagrass, St. Augustinegrass, seashore paspalum, and zoysiagrass. In addition, notable positive increments for this trait were documented for each cycle compared to the standard cultivars, particularly in bermudagrass, St. Augustinegrass, and zoysiagrass. While heritability was higher for visually assessed traits, genetic increments were more pronounced for imagery-assessed traits.

The pacific shoot‐gall nematode ( Anguina pacificae ) is a serious pest of annual bluegrass ( Poa annua ) putting greens in coastal Northern California. Until recently, there have been relatively few effective plant protectant compounds against this endoparasitic nematode that infects shoots. This study evaluated the efficacy of cyclobutrifluram, which targets the mitochondrial succinate dehydrogenase complex of nematodes and fungi. Three studies were conducted from 2021 to 2024 at TPC Harding Park Golf Course in San Francisco, CA. Cyclobutrifluram was applied alone at a rate of 125, 250, or 500 g a.i. ha −1 or in combination with abamectin applied at 360 g a.i. ha −1 (3.9 g L ha −1 of product). Fluopyram applied at 500 g a.i. ha −1 (1.25 L ha −1 of product) was included as a standard. Cyclobutrifluram significantly improved turfgrass visual quality and reduced nematode injury compared to the untreated control, and overall effects were comparable to fluopyram. Tank mixtures or rotations with abamectin did not increase efficacy unless nematode pressure was high. These findings suggest that cyclobutrifluram is an effective plant‐protectant compound for managing pacific shoot‐gall nematodes.

Pacific shoot-gall disease, caused by the plant-parasitic nematode Anguina pacificae , also known as Pacific shoot-gall nematode (PSGN), poses a significant threat to annual bluegrass ( Poa annua ) putting greens in coastal Northern California, compromising turf quality and playability. This study evaluated the curative efficacy of fluopyram and abamectin applied at varying rates and frequencies from Oct 2019 to Nov 2020 in San Francisco, CA, USA. Abamectin was applied at 24.4, 32.6, or 48.9 oz·1000 ft −2 (Divanem, Syngenta Crop Protection LLC, Greensboro, NC, USA), and fluopyram was applied at 0.195 or 0.39 oz·1000 ft −2 (Indemnify, Bayer Environmental Science US LLC, Cary, NC, USA). Treatments included single and sequential applications to assess their effectiveness in suppressing PSGN and improving turf quality. By the second season, all fluopyram treatments reduced disease cover to <1%. Abamectin, applied either at 48.9oz·1000 ft −2 twice or at 24.4 oz·1000 ft −2 four times, reduced disease cover to <10%, a level statistically comparable to most fluopyram treatments. Both nematicides effectively suppressed PSGN gall formation; however, neither product significantly impacted PSGN population in our samples due to the immobility of the a.i., they protected the shoots from pathogens’ invasion and disease development. Turfgrass visual quality improved to acceptable levels (score >6) across all treated plots, with fluopyram-treated plots exhibiting higher quality than those treated with abamectin. Overall, these findings support fluopyram as the primary option for managing Pacific shoot-gall disease in annual bluegrass putting greens. Fluopyram applied twice at 0.39 oz·1000 ft −2 provided the most consistent and long-lasting disease suppression along with superior turf recovery. Importantly, the results also demonstrate that abamectin can be effective, although it requires higher rates and/or more frequent applications to approach the efficacy of fluopyram.

Increasing droughts coupled with decreasing available water resources in the southwestern United States highlight the need for new turfgrass cultivars that require less water. A field study evaluated a set of experimental and commercial bermudagrasses ( Cynodon Rich. species) for responses to prolonged and repeated drought conditions in Riverside, CA (USDA Hardiness Zone 10a). Irrigation was withheld for two successive 60‐day cycles of drought, each followed by 14‐day recovery periods in 2020, 2021, and 2022. Plots were evaluated weekly for turf quality and leaf firing, as well as living green coverage, normalized difference vegetation index, and dark green color index using digital imagery. Using living green coverage as a metric for drought performance, seven experimental genotypes (UCRC180012, UCRC180037, UCRC180040, UCRC180146, UCRC180217, UCRC180229, and UCRC180557) were consistently among the top 10 performers, on average retaining over 50% green coverage by the end of each dry‐down cycle. In comparison, all check bermudagrass [ Cynodon dactylon (L.) Pers.] (Riley's Super Sport [Celebration®]) and hybrid bermudagrass ( C. dactylon × C. transvaalensis Burtt Davy) (Bandera®, Santa Ana, DT‐1 [TifTuf®], Tifway II) cultivars had low to moderate responses, ranging from 36% to 0% green coverage. Riley's Super Sport and DT‐1 ranked the highest among check cultivars across years and cycles. Some genotypes appeared to show stress memory, where the first drought period in a year appeared to prime them for a more successful second period each year. Results demonstrate extensive variation among bermudagrasses ( Cynodon spp.) in response to drought and that evaluation over repeated drought cycles appears to be a useful selection tool for Mediterranean climates.

Managing turfgrass in arid and semiarid areas of the southern United States is becoming increasingly challenging due to prolonged drought and diminishing water resources. Turfgrass managers have been seeking products that control pests while promoting drought resistance. CivitasTM Turf Defense is a new petroleum-derived spray oil (PDSO) mixed with green pigment. Like other traditional PDSO products, Civitas is reported to have positive effects on turfgrass pest control and management. However, limited information is available regarding its impact on water conservation in turfgrass. The objective of this study was to evaluate the effects of Civitas on bermudagrass (Cynodon spp.) under deficit irrigation conditions. A 2-year study was conducted in Riverside, CA, USA, to evaluate the effect of Civitas on bermudagrass irrigated at 55% or 65% of reference evapotranspiration (ETo), which represented a 20% or 10% savings in water, respectively. Civitas was applied at 4.5 or 8.5 oz/1000 ft2 every two weeks (2019–20), and 8.5 oz/1000 ft2 every 3 weeks (2019 only), compared with an untreated control. Results show that Civitas improved bermudagrass quality under deficit irrigation at both rates, but the 3-week application interval was less effective compared with the 2-week application interval at either rate. Civitas applied at 8.5 oz/1000 ft2 every 2 weeks resulted in better turfgrass quality than the 4.5 oz/1000 ft2 rate in the first year only. Results suggest that using Civitas on bermudagrass can save up to 20% water while maintaining desirable turf quality.

In the last decade, due to prolonged and persisting drought conditions, California initially restricted water for outdoor landscape irrigation, and subsequently offered turf removal rebates to homeowners. Nevertheless, the effects of turf removal on land surface temperature (LST) in the region have not been investigated. Temperature differences between artificial and natural turf were assessed over time across four counties in Southern California using MODIS/ASTER airborne simulator (MASTER) with a spatial resolution of 5–50 m. Moreover, airborne thermal imagery (submeter spatial resolution) was acquired over selected areas of the city of Riverside, CA, during the summers of 2018 and 2019, including neighborhoods with different income levels, and temperatures for natural turf, artificial turf, and xeriscape were recorded. Environmental and socioeconomic data were compared to the LST in different neighborhoods. Results showed that the LST difference between artificial and natural turf increases in Southern California moving from coastal region to inland. Airborne thermal imagery in Riverside confirmed that University of California artificial turf fields are irrigated during the summer to allow athletes to use the pitch. No correlation between socioeconomic factors and LST of turf and artificial turf fields (and paired differences) was found. On a city scale, natural turf lawns were consistently cooler than xeriscape and artificial turf lawns, closely mirroring mean air temperature. Socioeconomic factors do not describe LST in residential lawns, as warmest and coolest lawns regardless of vegetation are found evenly distributed among different income neighborhoods. Turfgrass removal for water conservation may have unforeseen environmental side effects.

Methiozolin is labeled for goosegrass and smooth crabgrass control in golf course putting greens, but no peer-reviewed literature exists regarding this use. Greenhouse experiments were conducted evaluating goosegrass and smooth crabgrass response to increasing rates of methiozolin as affected by weed growth stage. In general, as weed growth stage increased, the methiozolin rate required to reduce weed biomass 90% (WR90) increased. Goosegrass was more sensitive to preemergence-applied methiozolin than smooth crabgrass, and the WR(90 )was 30.4 and 118 g ai ha(-1) for goosegrass and smooth crabgrass, respectively. However, smooth crabgrass was generally more sensitive to postemergence-applied methiozolin than goosegrass. Subsequent field studies were conducted to evaluate goosegrass and smooth crabgrass control with methiozolin applied singularly or sequentially at standard preemergence timings. Results indicated methiozolin applied singularly or sequentially at the label-recommended rate (500 g ha(-1)) is not persistent enough to provide season-long control of goosegrass and smooth crabgrass. Ten field studies were conducted in Alabama, California, Florida, and Virginia to evaluate frequent methiozolin application programs with the objective of providing selective, season-long goosegrass and smooth crabgrass control. Results from these studies indicate methiozolin can be safely applied to hybrid bermudagrass and creeping bentgrass putting greens despite exceeding the yearly maximum use rate for putting greens (2,500 g ha(-1)) with some treatments. Methiozolin effectively controlled smooth crabgrass throughout the growing season in California and Virginia when 10 biweekly applications were applied at 250 g ha(-1) or higher. In Florida, methiozolin did not acceptably (80%) control goosegrass regardless of application rate. In Virginia, methiozolin acceptably controlled goosegrass only when applied at rates and frequencies that exceeded the maximum yearly methiozolin usage rate. These data indicate that methiozolin has the potential to control smooth crabgrass preemergence when applied frequently, but does not provide acceptable goosegrass control at labeled rates.

Positive effects on plant health provided by quinone outside inhibitors (QoI) and other fungicide classes have been previously reported in turfgrass and other agricultural crops. However, most of the research was conducted under controlled environmental rather than field conditions. Two field and one greenhouse experiments were conducted and repeated in southern California from 2011–2013 to test the ability of selected fungicides to retain or improve creeping bentgrass ( Agrostis stolonifera L.; CBG) quality and rooting characteristics when exposed to drought stress induced by multiple abiotic stressors, including, heat and traffic. Fungicide treatments were applied on 14-d or 28-d intervals prior to and during implemented stress periods for a total of 2–5 applications and consisted of azoxystrobin, chlorothalonil + acibenzolar-S-methyl (ASM), fluoxastrobin, aluminum tris, penthiopyrad, pyraclostrobin, pyraclostrobin + boscalid tested against a nontreated control (NTC). No disease symptoms were present in any trial site, but the presence of turfgrass pathogens was not determined. Although increased root diameter in comparison to NTC was observed in plants treated with azoxystrobin and pyraclostrobin + boscalid, and increased root volume was observed in pyraclostrobin + boscalid in the greenhouse study, no significant differences in rooting characteristics were found in the field studies. Moreover, none of the fungicide treatments improved turf quality or normalized difference vegetation index (NDVI) in any of the experiments. Results imply that fungicides offer little to no secondary benefits in regard to abiotic stress such as drought alleviation in arid environments, when disease pressure is minimal or absent.

A 10-yr, four-phase collaborative effort among three universities was conducted to develop new hybrid zoysiagrasses (Zoysia spp. Willd.) with improved turf quality, winter hardiness, and pest resistance in comparison to commercial zoysiagrass cultivars, especially 'Meyer' (Z. japonica Steud.). In Phase 1, breeding efforts produced 2,858 new progeny that were evaluated for 2 yr across three sites. In Phase 2, only 60 (2%) of 2,858 progeny were selected for advancement to 10 replicated multiyear field trials (Phase 3). Phase 3 revealed 10 promising progeny (assigned DALZ numbers) that required further intensive field and laboratory testing in Phase 4. Phase 4 revealed differences in establishment rate, and DALZ 1701, 1702, 1707, and 1810 had moderate-to-good turf performance across seven sites, whereas DALZ 1808 had similar or slightly lower performance. Meyer consistently performed poorly, and 'Innovation', a recently released hybrid cultivar, had poor-to-moderate performance in comparison to the experimental genotypes, which illustrates the improvements achieved in zoysiagrass breeding in the last 10 yr. Freeze tolerance (LT50, lethal temperature killing 50% of the plants) ranged from -9.8 degrees C (Diamond) to -14.1 degrees C (DALZ 1812) with a mean of -12.5 degrees C. Evidence of large patch [Rhizoctonia solani Kuhn, anastomosis Group (AG) 2-2 LP] in the top 10 DALZ genotypes was 15 to 40% lower than Meyer on several dates. Results indicate that there are multiple genotypes for potential release in the future with improved turf color, winter hardiness, freeze tolerance, large patch resistance, and finer leaf texture suitable for USDA plant hardiness zones ranging between 5b and 8a.

The Pacific shoot-gall nematode ( Anguina pacificae Cid del Prado Vera & Maggenti, 1984) is a devastating pest on annual bluegrass ( Poa annua L.) putting greens in coastal Northern California, USA. Frequently used plant protection compounds such as fenamiphos and azadirachtin are either no longer registered or very expensive and have often resulted in nematode suppression at best. A new formulation of abamectin (Divanem; Syngenta, Greensboro, NC) was tested at two rates (0.15 and 0.30 kg a.i. ha − 1 ) and two application frequencies (2X vs. 4X) in comparison to fluopyram (Indemnify; Bayer CropScience, St. Louis, MO) applied at the rate of 0.5 kg a.i. ha − 1 on three California golf courses: Pasatiempo, Santa Cruz; Laguna Seca, Monterey; and Del Monte, Monterey. Fluopyram showed the best efficacy regarding from and against the Pacific shoot-gall disease. two applications for season-long applications of the new formulation rate efficacy fluopyram. Overall, represents plant tool offers a treatment alternative for the management of this pathogen. Neither had much effect on populations of soil-dwelling A. pacificae , spiral ( Helicotylenchus spp.), ring ( Criconemoides spp.), and root-knot ( Meloidogyne spp.) nematodes.

Decreased stand uniformity together with reduced aesthetics and play-ability caused by annual bluegrass (Poa annua) intrusion in creeping bentgrass (Agrostis stolonifera) putting greens is one of the major problems that golf course superintendents face with managing newer playing surfaces. Few herbicides are registered for selective control of annual bluegrass in creeping bentgrass greens, and the risk of herbicide resistance remains an issue, thus use of plant growth regulators (PGRs) is still the primary method of annual bluegrass suppression. This study was conducted to evaluate eight PGR treatments, employed as a series of 15 consecutive, biweekly applications to suppress annual bluegrass encroachment in 'Pure Distinction' creeping bentgrass maintained as a golf course putting green in Los Angeles, CA. Best annual bluegrass suppression was observed with products containing flurprimidol (FP) at 0.256 lb/acre, paclobutrazol (PB) at 0.119 lb/acre, or three-way mixture of FP, trinexapac-ethyl (TE), and PB (FP+PB+TE) at 0.055, 0.014, and 0.055 lb/acre, respectively. Although all treatments caused some significant creeping bentgrass injury, which increased over time, PB at 0.119 lb/acre and FP+PB+TE at 0.055, 0.014, and 0.055 lb/acre, respectively, appeared to be safest among effective treatments. Additionally, those treatments caused significantly darker green turf, which may be desirable on putting greens. This research confirms the potential of PGR use to limit annual bluegrass infestation on creeping bentgrass greens in a Mediterranean climate and reveals the most effective treatments that could be used in a putting green maintenance program.

Cynodon Rich. is one of the major turfgrass and forage genera in warmer climates of the United States and other world regions. New cultivars of Cynodon spp. are often developed by hybridization of a limited number of accessions of two species-C. transvaalensis Burtt Davy and C. dactylon (L.) Pers.-or by selection from existing cultivars. This may lead to an erosion of diversity. Several other species of this genus also exhibit desirable traits, and they could be used in the development of new cultivars to increase the range of genetic variation. In this study, the genetic diversity of seven Cynodon species was assessed using Diversity Array Technology sequencing (DArTseq). This technology is capable of identifying single nucleotide polymorphism (SNP) markers with no prior DNA sequence information. The 85 analyzed accessions showed considerable genetic variation and formed several distinct groups based on the degree of relatedness. However, none of these groups were comprised of only accessions of the same species, suggesting that DNA marker groupings are not well in agreement with botanical classification for this genus. The identification of species-specific SNP markers provides an additional tool for species reclassification and may clear up pedigrees of some established cultivars.

Wetting agents have been reported to alleviate localized dry spot and save water while maintaining turf quality at an acceptable level. However, limited research has been conducted on comparing the effects of different wetting agent products. A study was conducted from May to October in 2018 and 2019 in Riverside, CA to evaluate 10 wetting agent treatments on performance of 'Tifway II' hybrid bermudagrass [Cynodon dactylon (L.) Pers. x C. transvaalensis Burtt Davy] under deficit irrigation at three reference evapotranspiration (ETo) levels: 45, 55, and 65% ETo. Ten wetting agent treatments were selected based on manufacturer recommendations. Plots were evaluated for visual turf quality, percent green cover (PGC), dark green color index, normalized difference vegetation index (NDVI), soil volumetric water content, soil moisture variability, and proline content in dry-leaf samples. Wetting agent treatments improved turf quality and PGC, and decreased soil moisture variability. Moreover, up to 16% increase in soil moisture levels was observed on treated vs. untreated control. No differences were observed for NDVI, proline content in leaves, or fall color retention. Overall, soil moisture variability declined in 2019, and turf quality improved in both years when any wetting agent treatment was applied, and only minor differences were observed among wetting agent treatments evaluated in this study. Other physiological indicators and soil rootzone characteristics are needed to gauge the effects of wetting agents under deficit-irrigated turfgrass.

Kikuyugrass [Cenchrus clandestinus (Hochst. ex Chiov.) Morrone] is considered either an invasive weed or the desired species on many golf courses, athletic fields, and other turf areas along coastal and inland California. A field study was conducted at the University of California, Riverside in 2012 and 2013 on 'Whittet' kikuyugrass mowed at 11 mm to identify management practices for producing sufficient turf quality and optimal playing conditions for golf course fairways and athletic fields. The study evaluated the effect of mowing frequency (three vs. six times per week), cultivation practice (verticutting vs. grooming), applications of trinexapac-ethyl (TE), and nitrogen fertilization rates (96 vs. 240 kg N ha(-1) yr(-1)) on turf quality, Normalized Difference Vegetation Index (NDVI), turf firmness, ball roll distance (BRD), and tensile strength. Mowing six times per week produced the highest turf quality turf during summer when kikuyugrass grows most vigorously, while trends were not clear for cultivation practice effects on turf visual quality. However, verticutting twice per year produced the least scalped and firmest turf, while decreasing BRD. Application of TE increased turf quality, NDVI, and BRD, but decreased tensile strength of the sward. Slightly higher turf quality was detected in plots fertilized at 240 kg N ha(-1) yr(-1) compared to those fertilized with the low N rate (6.0 vs. 5.8), but results do not seem to justify higher N fertility. Overall, results demonstrated that kikuyugrass available in California could benefit from high input management practices such as TE applications, high mowing frequency, and verticutting.

Golf courses in coastal regions of northern California are often faced with severe injury caused by pacific shoot-gall nematodes (Anguina pacificae) on their annual bluegrass (Poa annua) host in putting greens. For years, fenamiphos was used for mitigating disease outbreaks until its registration was withdrawn in 2008. An alternative product containing azadirachtin was intended for nematode suppression. Still, it required repeated applications throughout the year with questionable efficacy, making attempts to lessen the impact of the pathogen costly. This study evaluated fluopyram as a novel nematicide for control of pacific shoot-gall disease. Various application frequencies and rates were tested at several golf courses affected by the nematode. Results revealed that fluopyram applied once at 0.22 lb/acre reduced the number of new shoot-galls and improved annual bluegrass appearance for several months. Increased rates and application frequency occasionally improved the efficacy further. Although the visual quality of turf treated with this plant protection compound was tremendously enhanced, and the number of new shoot-galls was reduced, rarely a significant effect was observed on the population density of several soil-dwelling plant-parasitic nematodes, including pacific shoot-gall nematode. It is hypothesized that fluopyram did not move significantly past the thatch layer and into the soil. However, it effectively reduced the ability of pacific shoot-gall nematode juveniles to induce new shoot galls. Due to its long half-life, it likely protected against both new nematode infections and dissemination of pacific shoot-gall nematode when the shoot-galls decomposed.

Kikuyugrass [Cenchrus clandestinus (Hochst. ex Chiov.) Morrone (= Pennisetum clandestinum Hochst. ex Chiov.)] is a warm-season grass native to Africa. It was introduced into the United States as forage in Hawaii and for erosion control in California. Kikuyugrass is considered invasive and currently is on the USDA's noxious weed list. Since complete eradication is difficult, it has become the primary species on several golf courses, athletic fields, and lawns. Kikuyugrass possesses exceptional quality with considerable cultural inputs, and little or no winter dormancy compared with other warm-season turfgrasses. With breeding efforts directed specifically at reducing aggressiveness and improving texture, thus reducing inputs, it could become a valuable turf-type species in coastal and inland California. The genetic diversity of kikuyugrass was investigated using single nucleotide polymorphism (SNP) and silicoDArT (presence or absence) markers revealed by the Diversity Arrays Technology sequencing (DArTseq) platform. Accessions were sampled throughout California, Hawaii, and Australia, both from natural stands and various collections. Among the 254 accessions tested, two distinct groups were discovered, and there was no geographic pattern to this differentiation. The overall level of SNP polymorphism was low (polymorphic information content [PIC] average = .33, PIC median = .38). Most (76%) of the observed genetic variation was within populations, whereas 24% was among populations. Average genetic distances within populations ranged from 0.09 to 0.16, whereas distances among populations ranged from 0.13 to 0.36. Accessions from Hawaii and Australia were the most diverse; however, a detectable level of genetic diversity of kikuyugrass also exists in California, mostly because of the past introductions from Australia.

Persisting drought conditions in California are limiting water allocation for golf course irrigation. A study was conducted at the University of California, Riverside to determine if products including trinexapac‐ethyl (TE), a surfactant (Revolution), and nitrogen (N) fertilizer [Gro‐Power (5–3–1); SeaBlend (12–4–5) + StressRX (6–0–2) + XP Extra Protection (5–0–0); YaraLiva (15.5–0–0); Turf Royale (21–7–14); each applied at 25 g N m−2 yr−1) could enhance quality of ‘Princess 77’ bermudagrass (Cynodon dactylon L. Pers.) irrigated at 53 or 92% turfgrass evapotranspiration (ETc) under fairway conditions. Product and irrigation treatments were applied from May through October 2016 and 2017. Every 2 wk, plots were evaluated for visual quality, normalized difference vegetation index, soil volumetric water content using time domain reflectometry, and percent green cover using digital image analysis. Root samples were collected in November of both years, and fall color retention and spring green‐up were assessed using digital image analysis. At 92% ETc replacement, visual quality was highest in plots that received TE and surfactant. Although no differences were found among fertilizer treatments, fertilization alone was able to sustain visual quality at a minimally acceptable level at 92% ETc. Surfactant had the greatest positive effect on turf irrigated at 53% ETc, whereas TE did not improve visual quality on the same plots. Overall, results indicate that regular applications of either Revolution surfactant or SeaBlend + StressRX + XP Extra Protection can sustain bermudagrass visual quality at 53% ETc.Core Ideas Surfactants could substantially reduce irrigation requirements on bermudagrass turf. Fertilizers with low burning potential should be used in case of water restrictions. Deficit irrigation results in loss of quality during the summer months. Severe drought has an effect on bermudagrass root morphology.

Core Ideas Availability of water in arid zone may prevent the use of leaching; therefore, alternative methods need to be identified to manage salinity. Identify which commercially available products that are supposed to ameliorate soil chemical and physical characteristic have a real impact on soil chemistry. Test if soil salinity is affected not only by irrigation practices, but also other environmental factors, such as evapotranspiration. Increasing salinity issues caused by insufficient precipitation, drought, and increasing use of alternative nonpotable sources of irrigation water are a major concern for turf management in the southwestern United States. Modification of soil physicochemical properties that result from salinity is one means of alleviating plant salinity stress. A field study was conducted in 2013 and 2014 at the University of California, Riverside turfgrass research facility in Riverside, CA. Six commercial programs were tested for their ability to alleviate salinity stress on ‘Tifway II’ hybrid bermudagrass [ Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt‐Davy] irrigated with saline water (electrical conductivity = EC ≈ 4.4 dS m −1 ). These included: CrossOver (calcium silicate, magnesium silicate, and monosilicic acid); Revert (polyalkylene glycol); SUNBurst Cal Plus 8% (calcium carbonate and calcium nitrate) applied at 0.23 or 0.47 mL m −2 ; a combination of DeSal (carboxylic acid), Stress Rx (potassium nitrate, potassium acetate, and calcium nitrate) and XP Micro (urea, magnesium nitrate, manganese nitrate, manganese sulfate, ferrous sulfate, iron EDTA, kelp extract); and Turfcare Natural Plant Nutrient (Meliaceae spp. extracts). Plots were evaluated every 2 wk for visual turf quality, and Digital Image Analysis. Leachate was also collected and analyzed for EC on the same day. Soil samples were collected and analyzed for salinity at the end of each growing season. DeSal + Stress RX + XP Micro was the only treatment that resulted in acceptable visual quality (6.4) and decreased sodium adsorption ratio (SAR) and Na content in the rootzone by the end of the study.