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Annual bluegrass (Poa annua L.) and creeping bentgrass (Agrostis stolonifera L.) commonly coexist in turfgrass ecosystems but differ in drought tolerance, contributing to uneven turf quality. This study was conducted to examine the physiological and metabolic responses of P. annua and A. stolonifera to drought stress and rewatering and identify major metabolites associated with the interspecific variation in drought tolerance and recovery. Plants grown in controlled‐environment chambers were well irrigated (non‐stress control) or subjected to drought stress by withholding irrigation for 21 days. For the evaluation of post‐stress recovery, drought‐stressed plants were rewatered for an additional 21 days. Leaf relative water content, visual turf quality, green canopy cover, and leaf electrolyte leakage were measured weekly. Metabolomic analysis was performed with leaf tissue collected at 21 days of drought stress and 21 days of rewatering. Poa annua demonstrated lower drought tolerance and post‐stress recovery compared to A. stolonifera when drought‐stressed plants were compared to their respective control across physiological parameters. Metabolomic analysis identified a relatively greater upregulation of sugars and amino acids in A. stolonifera and downregulation of more carbon intermediates and nucleic acids in P. annua in response to drought stress. Upon rewatering, both species had declined sugar content and increased carbon intermediates and nucleic acids. The differential response to drought stress and recovery between A. stolonifera and P. annua could be attributed to a greater accumulation of sugars and amino acids involved in osmotic adjustment during drought stress and their utilization upon rewatering to stimulate post‐stress recovery in A. stolonifera. Core Ideas: Agrostis stolonifera had superior drought tolerance and greater recovery upon rewatering relative to Poa annua.Superior drought tolerance in A. stolonifera was associated with more accumulation of compatible metabolites for osmotic adjustment than in P. annua.Greater post‐stress recovery in A. stolonifera was associated with lesser extent of drought damage and more carbon or amino acid reserves relative to P. annua. Plain Language Summary: The differential response to drought stress and recovery between A. stolonifera and P. annua could be attributed to a greater accumulation of sugars and amino acids involved in osmotic adjustment during drought stress and their utilization upon rewatering to stimulate post‐stress recovery in A. stolonifera. [ABSTRACT FROM AUTHOR]

Organic matter and soil nutrient accumulation within putting green root zones affects surface quality and performance. Research was conducted to explore differences in organic matter and nutrient content within creeping bentgrass (CBG; Agrostis stolonifera L.) and ultradwarf bermudagrass [UDBG; C. dactylon (L.) Pers. × C. transvaalensis Burtt‐Davy] putting greens. Sampling was conducted from January 30 to February 23, 2023, on 22 putting greens (11 CBG and 11 UDBG) in Tennessee. Forty cores (1.91‐cm diameter by 10‐cm depth) were randomly collected from each putting green and analyzed for total organic material (TOM; undisturbed cores) by profile depth (0–2 cm, 2–4 cm, and 4–6 cm), TOM throughout a 10‐cm core, soil organic matter (SOM; passed through sieve with 2 mm openings) throughout a 10‐cm core, and nutrient content. All organic matter measurements were determined via loss‐on‐ignition (LOI) testing, whereas nutrient content was determined by Mehlich‐3 extraction. LOI testing at 440°C resulted in greater TOM values than 360°C; however, values from both temperatures were closely related (R2 = 0.99). TOM values from UDBG greens were greater than those recorded on CBG at all profile depths. Greens established via no‐till conversion contained more TOM than those planted in a constructed sand‐matrix root zone. While TOM and SOM were associated (R2 = 0.62), removing verdure for SOM assessments reduced the amount of organic material in each sample by 38% and increased variability. Nutrient contents were lower than sufficiency level of available nutrients benchmarks but exceeded minimum levels for sustainable nutrition. Core Ideas: Findings align with standards for measuring soil organic matter at varying profile depths in putting greens with verdure included.Ultradwarf bermudagrass greens in Tennessee contain more organic material than those surfaced with creeping bentgrass.Putting greens established via no‐till conversion contain more organic material than those planted into new sand.Organic material is most abundant in the uppermost 2 cm of a putting green root zone, regardless of species or rootzone type.Nutrient content in putting green root zones in Tennessee exceeded minimum levels for sustainable nutrition (MLSN). [ABSTRACT FROM AUTHOR]

The second-order difference equation $ x_{n+1} = a x_n + (b+cx_{n-1}) e^{-x_n} $ x n + 1 = a x n + (b + c x n − 1) e − x n , where 0

The annual bluegrass weevil, Listronotus maculicollis Kirby, is considered the most destructive insect pest of short‐mown turfgrasses in northeastern North America. Poa annua L. is the preferred host plant, though the weevil can develop in other cool‐season (C3) turfgrasses such as bentgrasses (Agrostis spp. L.) and perennial ryegrass (Lolium perenne L.). Recently, damaging populations have been reported in midwestern and southeastern United States, where cool‐ and warm‐season (C4) turfgrasses are grown. However, it is unknown whether L. maculicollis can establish and develop within common warm‐season turfgrasses such as zoysiagrasses (Zoysia matrella L.) and hybrid bermudagrasses (Cynodon dactylon Pers. × transvaalensis Davy). Larvae reared on Agrostis stolonifera ‘Penncross’, an older cultivar, experienced a significant reduction in survivorship and longer development periods compared to a newer cultivar (Penn‐A4) and P. annua. Agrostis stolonifera ‘Penncross’ possessed significantly greater quantities of carotenoids and flavonoid content, which may explain differences in host suitability among C3 turfgrasses. No larvae were recovered from C4 hosts in no‐choice ovipositional assays, suggesting Z. matrella and C. dactylon × transvaalensis are nonviable hosts of L. maculicollis. Further investigation into the morphological and physiological defense mechanisms in Z. matrella and C. dactylon × transvaalensis may broaden our understanding of tolerance mechanisms not observed in C3 cool‐season turfgrasses and provide guidance for future breeding efforts. [ABSTRACT FROM AUTHOR]

The elemental allelopathy hypothesis states that the metal‐rich litter of hyper‐accumulating species may have a detrimental impact on neighbouring plants giving a competitive advantage to hyper‐accumulators. Here, we aim to specify the conditions of application of this hypothesis in realistic field conditions, and its relative importance compared to other positive effects found in metalliferous systems.We disentangled the litter‐induced elemental allelopathy and canopy effects of two metallophyte species (Arenaria multicaulis and Hutchinsia alpina) with different levels of leaf Zn and Cd accumulation on two ecotypes of Agrostis capillaris with different levels of metal tolerance. The experiment was conducted in two habitats with contrasting pollution levels in a former mining valley in the Pyrenees (France).The metallophyte species that accumulates more metals (Hutchinsia alpina) showed a strong elemental allelopathy effect on the target with lower metal tolerance in the habitat with lower pollution level, while the metallophyte species that accumulates less metals (Arenaria multicaulis) had no litter effect. Both metallophyte species had positive canopy effects likely due to improvement of micro‐climatic conditions. The drought that occurred during the experiment may have influenced these canopy effects, increasing their importance during the course of the study. For Hutchinsia alpina, the positive canopy effects were stronger than the negative litter effects, resulting in overall positive effects on both target ecotypes.Synthesis. Our results brought a better understanding of the occurrence of elemental allelopathy in metallophyte communities and its relative importance as compared to micro‐climatic facilitation in a global warming context. [ABSTRACT FROM AUTHOR]

Urban grasslands span climates and topography in soils with variable water infiltration and drainage rates that result in occasional waterlogging stress, while data on grass species tolerance to waterlogging stress is scant. Whole plant responses to waterlogging stress among cool‐season grass species were quantified in a controlled environment. The following grasses were grown in well‐drained vs. waterlogged soil for 55 d: strong creeping red fescue (Festuca rubra ssp. rubra), slender creeping red fescue (F. rubra ssp. littoralis), Chewings fescue (F. rubra ssp. commutata), hard fescue (F. brevipila), tall fescue (F. arundinacea syn. Schedonorus arundinaceus), Kentucky bluegrasses (Poa pratensis), annual bluegrass (P. annua), rough bluegrass (P. trivialis), creeping bentgrass (Agrostis stolonifera), perennial ryegrass (Lolium perenne), and alkaligrass (Puccinellia distans). Five cultivars of each fine fescue (Festuca spp.) taxon were included for comparison. When grown in waterlogged soil compared to well‐drained conditions, relative differences generally ranged from −3% to −26% (shoots) and −13% to −33% (roots) for creeping bentgrass, tall fescue, and Kentucky bluegrass indicating higher waterlogging stress tolerance. The relative differences ranged from −18% to −43% in shoots and −3% to −34% in roots for annual bluegrass and perennial ryegrass indicating fair performance under waterlogging stress. Fine fescues, rough bluegrass, and alkaligrass exhibited the poorest performance during waterlogging stress with plant responses ranging from −12% to −64% (shoots) and −17% to −73% (roots). Negative whole plant responses among cultivars of four fine fescue taxa were similar. The selection of grasses tolerant to waterlogging stress will be important in developing resilient landscapes. [ABSTRACT FROM AUTHOR]

The grass species, Agrostis stolonifera, is commonly used on golf course and lawn bowling greens and can experience frequent fungicide applications, which has given rise to problems with fungicide resistance in major turfgrass pathogens. There are other organisms in this environment which may be naturally tolerant to particular fungicides. This work investigated the identity and diversity of organisms isolated from A. stolonifera leaves, which presumably have had very little exposure to fungicides. Samples were collected monthly throughout two growing seasons. Over 2400 leaf blades were placed on a selective growth medium to select for propiconazole-tolerant fungi. The isolates were resolved into 19 different species using ITS DNA sequencing. The appearance of species was consistent between the two sampling seasons, with ten species in March through May, two additional species in June through July, and another seven species in September through October. The four species that showed the greatest representation among the ~ 2200 isolates were as follows: Microdochium bolleyi (23%), Rhizoctonia solani (11%), Papiliotrema flavescens (9%), and Cryptococcus aspenensis (9%). This study is the first report of Mucor nidicola, Parasarocladium breve, Trichoderma gamsii, T. caribbaeum, and Blakeslea trispora isolated from the A. stolonifera phyllosphere. Why these fungal species show tolerance toward propiconazole remains to be explored, as well as whether the genetic factors conferring resistance are the same as those that produce acquired resistance, and whether this resistance is intrinsic to these species. [ABSTRACT FROM AUTHOR]

Climate change mitigation requires creative solutions to reduce greenhouse gases (GHG). Little research has been performed on GHG emissions from shaded turfgrass systems, resulting in a lack of best management practice (BMP) development. The aim of this research was to investigate the soil flux of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) as impacted by shade [shade (98.8%) versus sun (100%)] and differing sources (fast- versus slow-release) and rates (147 versus 294 kg ha−1 yr−1) of nitrogen (N) fertilizers on creeping bentgrass putting greens. The results show that emissions of soil CO2 and soil N2O are significantly lower in shaded plots versus sunny plots. The presence of N fertilizer significantly increased soil CO2 emissions over unfertilized plots. Quick-release N fertilizer fluxed significantly more soil N2O than the slow-release N fertilizers. Turfgrass color was significantly higher on the sunny green versus the shaded green except in late summer. Turfgrass quality was significantly higher for the shaded green versus the sunny green. Milorganite improved turfgrass quality whereas urea decreased turfgrass quality due to fertilizer burn. When N is needed to improve turfgrass color and quality, the use of slow-release N sources should be a BMP for shaded greens. [ABSTRACT FROM AUTHOR]

Brown patch (caused by various Rhizoctonia and Rhizoctonia‐like species) is a major summer disease for several cool‐season turfgrass species, including creeping bentgrass (CBG) (Agrostis stolonifera L.), colonial bentgrass (CLBG) (Agrostis capillaris L.), perennial ryegrass (PRG) (Lolium perenne L.), and turf‐type tall fescue (TTTF; [Schedonorus arundinaceus (Schreb.) Dumort., nom. cons.]). Elevated nitrogen (N) rates are suggested to enhance development of brown patch symptoms. A controlled environment study was conducted to determine the influence of two N rates among four cool‐season turfgrass species maintained at 1.9 cm after inoculation with R. solani. Field‐grown plants of four CBG cultivars, a CLBG cultivar, a PRG blend, and two TTTF cultivars were fertilized weekly, totaling 49 and 196 kg N ha−1 across four applications. Turfgrass responses were measured as relative growth rate, brown patch severity, and seasonal brown patch using area under the disease progress curve (AUDPC). On average, peak brown patch severity among the species and cultivars was between 22.6% and 68.1% for Raptor III TTTF and Penn A‐1 CBG, respectively. Turf‐type tall fescue cultivars decreased brown patch by 61% compared to CBG, CLBG, and PRG. The lower N rate reduced brown patch AUDPC by 17% and 33% for CBG and PRG, respectively, but N rate generally had no effect for CLBG and TTTF. These results reinforce the importance of planting disease‐resistant species and cultivars. Additionally, N rate may be an important factor affecting brown patch severity for select intensively managed turfgrass species. Core Ideas: Among the four cool‐season turfgrass species studied, tall fescue was the most resistant to brown patch.Brown patch‐resistant cultivars had significantly less disease compared to susceptible cultivars.Increased nitrogen rates were associated with enhanced brown patch in creeping bentgrass and perennial ryegrass.Nitrogen rate did not influence brown patch severity on the colonial bentgrass and tall fescue. [ABSTRACT FROM AUTHOR]

Aims: Global warming due to increasing greenhouse gas emissions intensifies frequency and duration of extreme high temperature which has become a primary threat to cool-season crops worldwide. Aim of this study was to examine root adaptability to high temperature regulated by γ-aminobutyric acid (GABA) associated with changes in antioxidant metabolism, root vitality, osmotic balance, and global metabolites remodeling in roots. Methods: A cool-season creeping bentgrass (Agrostis stolonifera) plants were pretreated with or without the 0.5 mM GABA before being subjected to heat stress (35/30 °C) or optimal temperature condition (23/19 °C) for 15 days. Roots were sampled to analyze changes in physiological parameters and metabolomics. Results: Heat stress significantly induced reactive oxygen species production in roots resulting in oxidative damage to proteins and cell membranes. However, the GABA could effectively alleviate heat-induced decline in total antioxidant capacity and also improve multiple antioxidant enzyme activities, root vitality, and osmotic adjustment ability in roots. Metabolomic analysis found that a total of 71 metabolites were jointly or differentially regulated by heat stress or heat stress together with the GABA application in roots. In response to heat stress, the GABA improved the accumulation of multiple amino acids, sugars, organic acids, and other metabolites (urea, putrescine, myoinositol, arbutin, campesterol, and stigmasterol) in roots. Conclusions: GABA could effectively increase antioxidant capacity, root vitality, and osmotic adjustment associated with improved root adaptability to heat stress. In addition, the GABA-regulated metabolites remodeling could be attributed to better energy metabolism, osmotic balance, antioxidant capacity, and cellular structures in roots under heat stress. [ABSTRACT FROM AUTHOR]

Creeping bentgrass (Agrostis stolonifera L.) is an important cool-season turfgrass species widely used for golf course putting greens; however, it experiences summer stress and quality decline in the U.S. transition zone and other regions with similar climates. Silicon (Si) may improve the abiotic stress of creeping bentgrass, but the mechanism of its impact on plant drought and heat tolerance is not well understood, and a few studies have reported on the effects of Si on creeping bentgrass drought and heat tolerance. The objectives of this study were to determine the effects of Ortho-silicic acid (Ortho-Si) on antioxidant metabolism and root growth characteristics and viability in creeping bentgrass under drought and heat-stress conditions. The three treatments, including control, Ortho-Si at 0.16 mL m−2 and 0.32 mL m−2, were applied biweekly to creeping bentgrass. Foliar application of the Ortho-Si exhibited beneficial effects on turf quality, physiological fitness, and root growth in creeping bentgrass. The Ortho-Si application at 0.16 mL m−2 and 0.32 mL m−2 improved turf quality ratings by 9.5% and 11.1%, respectively, photochemical efficiency (PE) by 6.9% and 8.5%, respectively, chlorophyll content by 27.1% and 29.9%, and carotenoids content by 25.5% and 27.2%, respectively, when compared to the control at the end of the trial. The Ortho-Si treatments enhanced antioxidant enzyme activity; the highest amount, in particular, increased superoxide dismutase (SOD) activity by 32.8%, catalase (CAT) by 12.8%, and ascorbate peroxidase (APX) activity by 37.4%, as compared to the control. The Ortho-Si application reduced leaf hydrogen peroxide (H2O2) concentration relative to the control. In addition, exogenous Ortho-Si improved leaf Si concentration. The Ortho-Si application at 0.32 mL m−2 increased root biomass by 52.7% and viability by 89.3% relative to the control. Overall, Ortho-Si at 0.32 mL m−2 had greater beneficial effects than the low rate (0.16 mL m−2). Exogenous Si may improve drought and heat tolerance by protecting photosynthetic function, enhancing the activities of leaf antioxidant enzymes, and stimulating root growth, viability, and Si uptake. The results of this study suggest that foliar application of Ortho-Si at 0.32 mL m−2 may be considered to be an effective approach to improve turf quality and physiological fitness of creeping bentgrass during the summer months in the U.S. transition zone and other regions with similar climates. [ABSTRACT FROM AUTHOR]

The challenge of managing invasive weed species continues to affect the agricultural industry, presenting ecological, economic, and agronomic hurdles that lead to over 100 billion USD in annual crop losses globally. One such concern is the management of Agrostis stolonifera L., commonly known as creeping bentgrass, particularly due to its ability to form hybrids. This scenario underscores the urgent need for innovative, effective, and environmentally sustainable herbicides, steering the focus toward natural substances as potential candidates. We report here a promising natural lactone, commonly known as menthalactone, which is derived from Mentha piperita L. Its phytotoxic activity was assessed against the monocot, bentgrass, and a dicot, lettuce (Lactuca sativa L.). Menthalactone displayed outstanding activity against bentgrass and was further evaluated for phytotoxic characteristics. The germination of A. stolonifera seeds was significantly inhibited with an IC50 value of 4.9 ± 1.2 µM. In contrast to bentgrass seeds, Lemna pausicostata L. plants were less responsive to menthalactone treatment, shown by an IC50 of 293.4 ± 70.6 µM. Both species are monocots, and the results suggest that menthalactone might have effects on seed germination but not on the metabolism of green tissues. The susceptibility of three common, obnoxious weed species, i.e., ryegrass (Lilium perenne), barnyard grass (Echinochloa crus-galli (L.) P. Beauv.), and crabgrass (Digitaria sanguinalis (L.) Scop.), to menthalactone was assessed. Menthalactone at 1000 µM completely inhibited the germination of all three species of grasses, while 330 µM inhibited germination by less than 50%. The post-emergence application of menthalactone at 1% did not produce a significant inhibitory effect against ryegrass, barnyard grass, or crabgrass. [ABSTRACT FROM AUTHOR]

Golf course superintendents may use bensulide to control annual grassy weeds and carfentrazone‐ethyl (CE) to control silvery‐thread moss (Bryum argenteum Hedw.) in creeping bentgrass putting greens. Creeping bentgrass injury has been reported if CE is applied soon after treatment with bensulide and the safe application interval varies as much as 68 days. Our goal was to improve the precision of recommendations for safe application of CE following bensulide, considering both CE rate and timing. We used a factorial treatment structure that included (1) bensulide or no bensulide, (2) three rates of CE, and (3) nine CE application timings in 2018 and 2019 at locations in Nebraska and Ohio. Because of limited effects in 2018, different CE rates and application timings were used in 2019. Significant creeping bentgrass injury was only observed at 6.7 or 13.4 fl oz acre−1 rates of CE that were applied within 3 days of applying bensulide. Even the 13.4 fl oz acre−1 rate (a 2× rate) of CE did not injure creeping bentgrass when applied at least 7 days after applying bensulide. The 2.0 fl oz acre−1 rate of CE never injured creeping bentgrass, even when applied the same day as bensulide. Cultivar, management, and environmental differences may influence whether subsequent application of bensulide and CE injures creeping bentgrass. Based on the environmental/cultural conditions and cultivars used in this research, golf course superintendents should expect little to no injury when CE is applied at least 1 week after applying bensulide. Plain Language Summary: The herbicides bensulide and carfentrazone‐ethyl are often used to control weeds in golf course putting greens, but researchers have reported injury to creeping bentgrass if carfentrazone‐ethyl is applied too soon after and application of bensulide. The objective of our research was to determine the safe application interval for various rates of carfentrazone‐ethyl following and application of bensulide. Based on this research, golf course superintendents should expect little to no injury when CE is applied according to label specifications and withheld for at least 7 days after applying bensulide. [ABSTRACT FROM AUTHOR]

As a result of intensive herbicide protection of crops against silky bentgrass (Apera spica-venti (L.) P. Beauv), numerous herbicide-resistant biotypes have been selected, mainly from the group of acetolactate synthase (ALS) inhibitors. We analyzed the development of herbicide-sensitive and herbicide-resistant biotypes of bentgrass and winter wheat under competition, taking into account selected physical and chemical properties of the soil, including nitrogen fertilization. The pot experiment (additive model) was conducted in the 2018/19 and 2019/20 seasons. The experimental factors included: (1) bentgrass with different sensitivity levels to herbicides from the groups HRAC/WSSA 1 and HRAC/WSSA 2, specifically two sensitive and three resistant biotypes; (2) two types of soil, sandy and clay; and (3) nitrogen fertilization, both with and without fertilization. Winter wheat and bentgrass development was assessed during each growing season, every 5 or 3 days from September until May, using the BBCH scale. The emergence date of the tested species/biotypes was recorded. The development of competing species was compared based on a new, proposed index: the duration of the developmental phases. As a result, the soil type and fertilization level differentiated wheat and bentgrass emergence dates and development. The autumn development of the competing species was slower and more uniform than the spring one. At the same time, the dynamics of the bentgrass and wheat development in the spring were greater. Bentgrass and winter wheat emerged earlier and grew more intensively on clay and fertilized soil. To sum up, no clear relationship was found between the resistance/sensitivity of bentgrass to herbicides and changes in the phenological development of plants in competition with winter wheat. [ABSTRACT FROM AUTHOR]

Lawn performs best with minimum inputs when grown in mixtures using more than a single grass specie. A study was conducted under open field conditions to evaluate the performance of four lawn grass species as mono-stand and in mixtures under mid-hill conditions at the Experimental Farm of the Department of Floriculture and Landscape Architecture, Dr Yashwant Singh Parmar University of Horticulture and Forestry, Nauni, Solan (H.P.) during March, 2020 to March, 2021. The experiment was laid out in a randomized block design with twelve treatments and three replications. Data was recorded at fortnight intervals for total weed count, chlorophyll content, number of mowing, and overall presentability just after turf establishment. It was observed that all turf grass mixtures, performed better than the monostands, during the entire course of the study. Turf grass mixture (50% 'Agrostis stolonifera' + 20% 'Festuca rubra' + 20% 'Lolium perenne' + 10% 'Cynodon dactylon)' required least number of mowing and was presentable throughout the year attaining highest presentability score of 22.98. [ABSTRACT FROM AUTHOR]

Organic N (oN, e.g., amino acids) is an important N-resource for plants in soils replete with oN but not inorganic N (iN; i.e., NH4+ and NO3−), such as cold ecosystems with temperature-limited soil decomposition rates. However, sub-Antarctic literature assumes that plants only acquire iN, potentially underestimating plant-available N. We hypothesised that Marion Island (− 46.90°, 37.75°) grasses (Polypogon magellanicus, Poa cookii, Agrostis stolonifera and Poa annua) acquire oN and that oN relative to iN provision affects plant growth. We investigated oN and iN uptake and growth responses in two hydroponics experiments. In situ N (15N-glycine, 15NO3− and 15NH4+) acquisition was investigated at three field sites with decreasing faunal influence, thus iN input and microbial activity. When plants grown in mire water were supplied with 15N-glycine or 15NO3−, root δ15N enrichment was highest for glycine-supplied plants. In the second hydroponics experiment, plant N-uptake rates (nmol g biomass−1 s−1) were significantly higher for glycine than NO3−, but relative growth rates (g g−1 d−1) lower on glycine. There were species-specific biomass allocation responses to N concentration (4 mM and 0.4 mM) and N-form (glycine and NO3−). Glycine-supplied grasses at the low iN concentration field sites had significantly higher δ15N enrichment relative to those at sites with high iN, suggesting higher oN uptake when iN is limiting. We demonstrate the importance of accounting for oN acquisition in the sub-Antarctic. As a system with high soil oN relative to iN, plants may predominantly meet N-demands through oN rather than iN acquisition. [ABSTRACT FROM AUTHOR]

Creeping bentgrass (Agrostis stolonifera) is sensitive to supra‐optimal temperature, which makes summer bentgrass decline (SBD) a main conundrum troubling turf manager. Diethyl aminoethyl hexanoate (DA‐6) is an artificial and bioactive plant growth regulator affecting tolerance to various abiotic stresses. It is commercially available for field application due to multiple advantages such as low cost, environmentally friendly compound, and sustainable effect. However, the positive effect and mechanism of DA‐6‐mediated heat tolerance in cool‐season grass species and SBD are not yet been explored. Objectives of the study were to screen the optimal dose of DA‐6 for improvement in thermotolerance and to investigate roles of DA‐6 in regulating photosynthesis, osmotic balance, and antioxidant homeostasis in two creeping bentgrass cultivars (heat‐tolerant 13 M and heat‐sensitive Seaside II) in controlled heat condition. Summer heat tolerance induced by the DA‐6 was further evaluated for 2 years under field conditions in a subtropical zone. Results demonstrated that the optimal dose of DA‐6 was screened as 0.1 mM based on analyses of chlorophyll content, photochemical efficiency, and cell membrane stability under heat stress. Foliar application of DA‐6 significantly alleviated heat‐induced leaf senescence by improving photosynthetic performance, accumulation of sugars (sucrose, fructose, and glucose) for osmotic homeostasis, and total antioxidant capacity for reactive oxygen species scavenging in the two cultivars. A 2‐year field test was further carried out to demonstrate that turf quality of the two cultivars was significantly improved after being treated by foliar DA‐6 during hot summer months in 2020 and 2021. Current findings suggested that DA‐6‐mediated thermo‐resistant mechanism was associated with photosynthesis, osmotic adjustment, and antioxidant in cool‐season grass species. Foliar application of DA‐6 could be a cheap, effective, and environmentally friendly strategy to alleviate SBD. Core Ideas: Foliar application of Diethyl aminoethyl hexanoate (DA‐6) could be a cheap, effective, and environmentally friendly strategy to alleviate summer bentgrass decline (SBD).DA‐6‐mediated thermo‐resistant mechanism was associated with photosynthesis, osmotic adjustment, and antioxidant.The optimal dose of DA‐6 for thermotolerance of creeping bentgrass was screened as 0.1 mM. [ABSTRACT FROM AUTHOR]

A rapid soil test for accurately estimating nitrogen (N) supply from soil organic matter would help turfgrass managers develop N fertilization programs. In this study, we tested the feasibility of using a quick test, mineralizable carbon (min‐C), to predict turfgrass growth and N uptake from sand‐based putting green soils. A 2‐year field experiment was conducted in Verona, WI, on four sand‐based research golf greens planted with creeping bentgrass. Nitrogen fertilizer was applied at 0, 10, and 20 kg ha−1 every 2 weeks as liquid urea during the growing seasons. Soil samples were collected at 0–5 cm and 5–10 cm and tested for min‐C by measuring the flush of CO2 following the rewetting dried soil, where the soil was rewetted at 50% water‐filled pore space and incubated at 25°C for 24 h. Min‐C was greater at the shallower soil depth, and unaffected by N rates that were applied. On‐site air temperature, soil moisture content, and estimated soil temperature were negatively related with min‐C, where r2 = 0.26–0.60 for air temperature, r2 = 0.32–0.71 for soil moisture content, and r2 = 0.16–0.53 for estimated soil temperature, indicating the test is quite sensitive to environmental conditions at the time of sampling. Furthermore, min‐C had weak positive to no relationship with creeping bentgrass growth rate (r2 = 0–0.17) and N uptake (r2 = 0–0.23) on sand‐based putting green, suggesting the test does not hold promise as a method for improving fertilizer decisions to these systems. Core Ideas: Soil mineralizable C was not predictive of creeping bentgrass growth or N uptake on sand‐based putting greens.Soil mineralizable C was substantially influenced by sampling depths on sand‐based putting green.Environmental variables including air temperature, soil temperature, and soil moisture affected soil mineralizable C of sand‐based putting greens. [ABSTRACT FROM AUTHOR]

As part of an ongoing taxonomic study of the genus Deyeuxia, typifications for 12 names belonging to subtribe Agrostidinae from South America are presented here. A neotype for Bromidium rigescens var. brevifolium is herein designated. Eleven names belonging to the genera Agrostis, Calamagrostis, and Deyeuxia are lectotypified. Epitypes for Calamagrostis heterophylla var. robustior and Deyeuxia velutina are designated. [ABSTRACT FROM AUTHOR]

70 species of grasses family (Poaceae), coming from genera: Agrostis, Alopecurus, Anthoxanthum, Apera, Arrhenatherum, Avena, Brachypodium, Briza, Bromus, Calamagrostis, Corynephorus, Cynosurus, Dactylis, Danthonia, Deschampsia, Digitaria, Echinochloa, Elymus, Eragrostis, Festuca, Glyceria, Helictotrichon, Hierochloe, Holcus, Hordeum, Koeleria, Leymus, Lolium, Milium, Molinia, Nardus, Panicum, Phalaris, Phleum, Phragmites, Poa, Saccharum and Setaria , collected mostly from natural stands in Poland during 2020 season, were subjected to GC-MS fingerprinting of headspace volatile fraction above dried material. Obtained mass spectrometry data were analyzed by means of principal component analysis (PCA) and hierarchical cluster analysis (HCA). Five species: Glyceria maxima (Hartm.) Holmb., Lolium multiflorum Lam., Hordeum jubatum L., Bromus tectorum L. and Bromus secalinus L. were identified as outliers, which is consistent with our earlier analysis by thin layer chromatography. These species deserve further look and their outliance is orthogonal to coumarin content, which was independently observed for odorant species of grasses. [ABSTRACT FROM AUTHOR]

Key message: The creeping bentgrass small heat shock protein AsHSP26.2 positively regulates plant growth and is a novel candidate for use in crop genetic engineering for enhanced biomass production and grain yield. Small heat shock proteins (sHSPs), a family of proteins with high level of diversity, significantly influence plant stress tolerance and plant development. We have cloned a creeping bentgrass chloroplast-localized sHSP gene, AsHSP26.2 responsive to IAA, GA and 6-BA stimulation. Transgenic creeping bentgrass overexpressing AsHSP26.2 exhibited significantly enhanced plant growth with increased stolon number and length as well as enlarged leaf blade width and leaf sheath diameters, but inhibited leaf trichomes initiation and development in the abaxial epidermis. These phenotypes are completely opposite to those displayed in the transgenic plants overexpressing AsHSP26.8, another chloroplast sHSP26 isoform that contains additional seven amino acids (AEGQGDG) between the consensus regions III and IV (Sun et al., Plant Cell Environ 44:1769–1787, 2021). Furthermore, AsHSP26.2 overexpression altered phytohormone biosynthesis and signaling transduction, resulting in elevated auxin and gibberellins (GA) accumulation. The results obtained provide novel insights implicating the sHSPs in plant growth and development regulation, and strongly suggest AsHSP26.2 to be a novel candidate for use in crop genetic engineering for enhanced plant biomass production and grain yield. [ABSTRACT FROM AUTHOR]

Mud pools are chemically similar to volcanism and are considered a pollution risk to ecosystems. The mud pools of Los Negritos, Michoacán, Mexico, additionally present untreated semi-urban wastewater discharges, livestock, and agricultural activities. This study aimed to identify sources, interaction, accumulation, spatial distribution, and mobilization of potentially toxic elements in water, soil, and plants of this site. The water is mainly alkaline (pH 7–8.45) with positive Eh values and T in the 17 to 63 °C range. The hydrothermal mud pools are the primary source of As found in water (1506 mg L−1), soil (153 mg kg−1), Agrostis sp. (108 mg kg−1), and Zea mays (115 mg kg−1). The potentially toxic elements seem immobilized in soil; even so, they are susceptible to being released when environmental conditions change, which represents a possible threat to the health of consumers by ingestion and bioaccumulation of As from water and corn. [ABSTRACT FROM AUTHOR]

This paper reports seven new records of Agrostis in Central and South America: A. boyacensis in Bolivia, Peru and Venezuela; A. lenis in Colombia, Ecuador and Venezuela; and A. mertensii in Costa Rica. The lectotype of Agrostis williamsii is herein designated. This contribution includes synonymy, iconography, geographic distribution and habitat, phenology, conservation status according to IUCN categories of threat, uses, and a list of additional specimens examined. [ABSTRACT FROM AUTHOR]

The identification of natural and environmentally friendly pesticides is a key area of interest for the agrochemical industry, with many potentially active compounds being sourced from numerous plant species. In this study, we report the bioassay-guided isolation and identification of phytotoxic and antifungal compounds from the ethyl acetate extract of Helietta parvifolia stems. We identified eight compounds, consisting of two coumarins and six alkaloids. Among these, a new alkaloid, 2-hydroxy-3,6,7-trimethoxyquinoline-4-carbaldehyde (6), was elucidated, along with seven known compounds. The phytotoxicity of purified compounds was evaluated, and chalepin (4) was active against Agrostis stolonifera at 1 mM with 50% inhibition of seed germination and it reduced Lemna pausicotata (duckweed) growth by 50% (IC50) at 168 μM. Additionally, we evaluated the antifungal activity against the fungal plant pathogen Colletotrichum fragariae using a thin-layer chromatography bioautography assay, which revealed that three isolated furoquinoline alkaloids (flindersiamine (3), kokusagenine (7), and maculine (8)) among the isolated compounds had the strongest inhibitory effects on the growth of C. fragariae at all tested concentrations. Our results indicate that these active natural compounds, i.e., (3), (4), (7), and (8), could be scaffolds for the production of more active pesticides with better physicochemical properties. [ABSTRACT FROM AUTHOR]

[Objectives]This study aimed to investigate turf characteristics, adaptability and difference in heat tolerance of creeping bentgrass（Agrostis stolonifera）cultivars（strains）in order to select stress-tolerant germplasm resources with potential for promotion and utilization. [Methods]With 14 creeping bentgrass cultivars（strains）as test materials, the field and pot experiment methods were used, respectively. Turf characteristics（density, uniformity, color, texture）and adaptability（drought tolerance, heat tolerance）were evaluated before and over summer in Nanjing region. Furthermore, turf quality heat tolerance index, growth rate, leaf length and leaf width were measured to evaluate heat tolerance under non-stress condition（25 ℃/20 ℃,day/night）and heat stress（38 ℃/28 ℃,day/night）. [Results]Turf characteristics and adaptability decreased obviously over summer in different cultivars（strains）. Comprehensive quality of T-1,Alpha and Barracuda（MVS-AP-101）were medium（4 to 5 score）as reflected by higher turf density, uniformity, color, texture and adaptability. In pot experiment, high temperature stress resulted in a decrease in turf quality heat tolerance index to 0.76-0.91 in all cultivars（strains）. System cluster analysis allowed 14 creeping bentgrass cultivars（strains）to be clustered into 3 categories based on turf quality heat tolerance index, including 5 heat-tolerant, 6 medium, and 3 heat-sensitive types. T-1,Luminary, Barracuda（MVS-AP-101）,Pure Distinction（PST-OJO）and 007 were heat-tolerant cultivars（strains）,and T-1 had a faster growth rate. [Conclusions]T-1 and Barracuda（MVS-AP-101）had better comprehensive quality and heat tolerance than other cultivars（strains）,which could be utilized in Nanjing region. [ABSTRACT FROM AUTHOR]

Emerging multidrug resistance (MDR) in Clarireedia spp. is a huge challenge to the management of dollar spot (DS) disease on turfgrass. Insight into the molecular basis of resistance mechanisms may help identify key molecular targets for developing novel effective chemicals. Previously, a MDR isolate (LT586) of C. jacksonii with significantly reduced sensitivities to propiconazole, boscalid, and iprodione, and a fungicide-sensitive isolate (LT15) of the same species were isolated from creeping bentgrass (Agrostis stolonifera L.). The present study aimed to further explore the molecular mechanisms of resistance by using genome-wide transcriptional analyses of the two isolates. A total of 619 and 475 differentially expressed genes (DEGs) were significantly down and upregulated in the MDR isolate LT586, compared with the sensitive isolate LT15 without fungicide treatment. Three hundreds and six and 153 DEGs showed significantly lower and higher expression in the MDR isolate LT586 than those in the sensitive isolate LT15, which were commonly induced by the three fungicides. Most of the 153 upregulated DEGs were xenobiotic detoxification-related genes and genes with transcriptional functions. Fifty and 17 upregulated DEGs were also commonly observed in HRI11 (a MDR isolate of the C. jacksonii) compared with the HRS10 (a fungicide-sensitive isolate of same species) from a previous study without and with the treatment of propiconazole, respectively. The reliability of RNA-seq data was further verified by qRT-PCR method using a few select potentially MDR-related genes. Results of this study indicated that there were multiple uncharacterized genes, possibly responsible for MDR phenotypes in Clarireedia spp., which may have important implications in understanding the molecular mechanisms underlying MDR resistance. [ABSTRACT FROM AUTHOR]

Aluminum (Al) toxicity is a major limiting factor for plant growth and crop production in acidic soils. This study aims to investigate the effects of γ-aminobutyric acid (GABA) priming on mitigating acid-Al toxicity to creeping bentgrass (Agrostis stolonifera) associated with changes in plant growth, photosynthetic parameters, antioxidant defense, key metabolites, and genes related to organic acids metabolism. Thirty-seven-old plants were primed with or without 0.5 mM GABA for three days and then subjected to acid-Al stress (5 mmol/L AlCl3·6H2O, pH 4.35) for fifteen days. The results showed that acid-Al stress significantly increased the accumulation of Al and also restricted aboveground and underground growths, photosynthesis, photochemical efficiency, and osmotic balance, which could be effectively alleviated by GABA priming. The application of GABA significantly activated antioxidant enzymes, including superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase, to reduce oxidative damage to cells under acid-Al stress. Metabolomics analysis demonstrated that the GABA pretreatment significantly induced the accumulation of many metabolites such as quinic acid, pyruvic acid, shikimic acid, glycine, threonine, erythrose, glucose-6-phosphate, galactose, kestose, threitol, ribitol, glycerol, putrescine, galactinol, and myo-inositol associated with osmotic, antioxidant, and metabolic homeostases under acid-Al stress. In addition, the GABA priming significantly up-regulated genes related to the transportation of malic acid and citric acid in leaves in response to acid-Al stress. Current findings indicated GABA-induced tolerance to acid-Al stress in relation to scavenging of reactive oxygen species, osmotic adjustment, and accumulation and transport of organic metabolites in leaves. Exogenous GABA priming could improve the phytoremediation potential of perennial creeping bentgrass for the restoration of Al-contaminated soils. [ABSTRACT FROM AUTHOR]

Perennial grasses have got greater attention in the past decade due to their potential to be productive over several years and their positive impacts on the environment. A great resource in this regard are the native species, which are well adapted to the specific conditions of the environment, but are often underestimated and irrationally used. The objects of study in the present research were 8 grasses (Festuca rubra, Lolium perenne, Dactilis glomerata, Arrhenatherum elatius, Festuca arundinacea, Briza maxima, Trisetum flavescens, Agrostis alba), typical for the Middle Balkan Mountains region, in order to assess their productivity and stability. The two-factor analysis of variance in terms of dry mass yield revealed significant influence of the factors of species, environment, and their interaction. During the 9-year experimental period, the highest yield was demonstrated by F. rubra (5.75 t ha-1), followed by F. arundinacea (5.54 t ha-1) and A. elatius (5.43 t ha-1). The stability parameters, calculated by the methods of regression analysis defined as stable the species of A. elatius and A. alba, and those, calculated by variance and non-parametric analyzes - F. rubra, D. glomerata and F. arundinacea. Differences in the stability assessment of the individual parameters are due to the fact that the different methods are based on different concepts of stability. The GGE biplot analysis, which integratedly assesses the species for their productivity and stability, identified F. arundinacea and A. elatius as the most favorable combining of these indicators. Trisetum flavescens was also characterized by good stability and average productivity. These species are suitable for cultivation in a wide range of environmental conditions. [ABSTRACT FROM AUTHOR]

Previous studies of the benefits of silicon (Si) supplementation in turfgrass have had inconsistent results. This study assessed the effect of Si supplementation on biomass production and Si accumulation of tall fescue (Festuca arundinacea) and bentgrass (Agrostis stolonifera). Plants were grown in buffered Hoagland's media (pH 6) with four sodium silicate (Na2SiO4) treatments (0, 0.5, 1, 2, and 4 mM Si). The two species responded differently to Si supplementation in terms of biomass. For bentgrass, biomass was enhanced by Si supplementation, but only significantly (p < 0.05) at the highest concentration (4 mM Si). Lower Si concentrations (0.5, 1, and 2 mM Si) significantly increased biomass in tall fescue compared to control, but there was no increase in biomass at 4 mM Si. There was a positive linear relationship between Si concentrations in media and Si concentrations in tissue. At 4 mM Si, the Si concentrations in aboveground tissue of tall fescue and bentgrass averaged 24 and 30.5 g kg−1 dry mass, respectively. Elevated Si concentrations in growth media promoted formation of silica bodies. The highest Si rates (4 mM Si) resulted in the highest silica body areal coverage in leaves of both species. We observed two silica body morphologies (which we termed long and barbed). Our findings indicate that tall fescue is likely to benefit from Si supplementation when soil pore water dissolved Si is below 0.5 mM, but increases in soil pore water dissolved Si above 2 mM are unlikely to increase biomass. In contrast, benefits in bentgrass may only be realized if dissolved Si in pore water is increased to 4 mM. [ABSTRACT FROM AUTHOR]

While not classified as an essential plant nutrient, silicon (Si) assimilation following exogenous Si application has enhanced the wear resistance of cool-season turfgrass. Given this beneficial supplementation of lignin by Si reported in epidermal tissue of monocotyledonous plants, our research objective was to quantify root morphology, vegetative nutrition and vigor, soil chemistry, and putting green performance in response to split applications of pelletized liming agents rich in Si and/or Ca and Mg. Field evaluation of granular liming agent treatment, 2441 kg (ha year)−1, was conducted on creeping bentgrass (Agrostis stolonifera L. cv. Penn G-2) putting green maintained in the Mid-Atlantic US. Pelletized Ca/Mg-SiO3 slag or dolomitic limestone treatments were conducted in frequent split applications and incorporated into the upper 5 cm of the rootzone. Measurements of canopy color and density, shoot growth as clipping yield, soil pH, Si and nutrient content of clippings, and soil extractable Si were performed each season. Cumulative Ca/Mg-SiO3 application (kg ha−1) increased mean acetic acid (HOAc) extractable Si by 35 to 60 mg kg−1 and leaf Si content by 1.0 to 1.5 mg g−1. However, neither putting green canopy quality, shoot nutrient concentration, 5 to 15 cm depth root length density nor ball roll distance was improved by liming agent treatment. Liming agent-treated or untreated plots showed statistical, yet inconsistent, differences in clipping yield 4, 14, 15, 16, and 17 months from initiation (MFI). This thorough shuffling of treatment rank, resulting in identical experiment-wide means precludes the expectation of dependably superior vigor by any. [ABSTRACT FROM AUTHOR]

Rhizobacteria that produce 1‐aminocyclopropane‐1‐carboxylic acid (ACC) deaminase (ACCd) that inhibits ethylene production may mitigate stress damages. The objectives of this study were to examine whether a novel strain of ACCd‐producing bacteria, Paraburkholderia aspalathi "WSF23," promotes plant tolerance to drought stress and post‐stress recovery and determine changes in metabolic profiles in leaves and roots associated with the positive ACCd‐bacteria effects in cool‐season perennial grass species. Creeping bentgrass (Agrostis Stolonifera L. cv. "Penncross") plants were inoculated with P. aspalathi "WSF23" and exposed to drought by withholding irrigation for 35 days, followed by re‐watering for 15 days in growth chambers. Inoculated plants demonstrated increased turf quality, canopy density, and root growth during drought stress and more rapid re‐growth upon re‐watering. Metabolomic analysis demonstrated that inoculation with P. aspalathi "WSF 23" increased the content of metabolites in the metabolic pathways related to stress defense, including osmoregulation, cell wall stability, and antioxidant protection in both leaves and roots, as well as nitrogen metabolism in roots of creeping bentgrass exposed to drought stress. The promotion of post‐stress recovery by P. aspalathi "WSF 23" was mainly associated with enhanced carbohydrate and pyrimidine metabolism and zeatin biosynthesis pathways in leaves and increased carbohydrates, biosynthesis of DNA and proteins, cellular metabolism, and TCA cycle activity in roots. These results provide insights into the metabolic pathways regulated by "WSF23," with the PGPR conferring improvements in drought stress tolerance and post‐drought recovery in a perennial grass species. [ABSTRACT FROM AUTHOR]

Creeping bentgrass (Agrostis stolonifera) experiences quality decline during summer in the United States transition zone and warmer regions. Various bioproducts have been used to improve creeping bentgrass performance and to mitigate effects of summer stress in the United States transition zone. This 2-year study was carried out to examine if foliar application of seaweed extract (SWE; Ascophyllum nodosum)-based biostimulant Utilize VR could enhance creeping bentgrass nitrate reductase (NaR) activity, and root viability under heat and drought stress conditions. The Utilize® was sprayed biweekly on creeping bentgrass foliage at 0, 29, 58, 87, and 116 mL.m-2, with application volume of 815 L.ha-2. Two weeks after first application, plants were exposed to heat (35/25 °C, day/night) and drought stress (40% to 50% evapotranspiration replacement) conditions for 42 days in an environment-controlled growth chamber. In general, the abiotic stress caused turf quality reduction. Foliar application of UtilizeVR at 58, 87, and 116 mL.m-2 increased turf quality, leaf color ratings, leaf chlorophyll, carotenoid content, and net photosynthetic rate (Pn). UtilizeVR at 58, 87, and 116 mL.m-2 increased NaR activity by 26.5%, 16.3%, and 16.3%, respectively, when compared with the control. UtilizeVR at 58, 87, and 116 mL.m-2 increased root biomass, root length, surface area (SA), and root volume when compared with the control. UtilizeVR at 58 and 87 mL.m-2 improved root viability by 16.3% and 30.9%, respectively, when compared with the control. Our data indicate that the SWE-based biostimulant UtilizeVR improves nitrogen (N) metabolism and root viability. UtilizeVR treatment at 58 mL.m-2 biweekly can be considered an effective approach for improving creeping bentgrass performance during summer stress. [ABSTRACT FROM AUTHOR]

Agrostis is one of the most diverse genera of the Poaceae, including ca. 198 species, principally distributed in cold and temperate regions of the world, but also found in the high mountains of the tropics. We present a revision based on morphoanatomical evidence, for the biogeographic region known as Megamexico 3 (i.e., Mexico including the desert areas of southern USA and the Central America territory, to northern Nicaragua). We include taxonomic descriptions and an identification key for the found taxa, maps with the known geographical distribution of the species, and figures with the morphoanatomical characteristics, elevation and phenology. Agrostis is represented in the study zone by 20 species, of which four are endemic and three are introduced. Most records of the genus are distributed in the mountains, above 1500 m a.s.l., in open areas of temperate forests, with conifers and Quercus. Specimens with spikelets occur year round, but most records occur during the wet season, in the months of July to October. We propose a preliminary conservation assessment for each species in the study zone, according to the International Union for Conservation of Nature categories: one with Deficient Data (DD), six as Endangered (EN), two as Vulnerable (VU), and 11 as Least Concern (LC). [ABSTRACT FROM AUTHOR]

A taxonomic treatment of 38 species of Muhlenbergia, a phylogeny based on analysis of six DNA sequence markers, and classification of Muhlenbergia for Central America (Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Panama; and Campeche, Chiapas, Quintana Roo, Tabasco, and Yucatán, México) is given. With the support from a molecular phylogeny we describe Muhlenbergia subg. Ramulosae subgen. nov. In our treatment we place M. gigantea (younger name) as a synonym of M. mutica. Lectotypes are designated for the names Agrostis microsperma Lag., Epicampes gigantea E. Fourn., Lamarckia tenella DC., Muhlenbergia adspersa Trin., M. diversiglumis Trin., M. exilis E. Fourn., M. flabellata Mez, M. setarioides E. Fourn., Pereilema ciliatum E. Fourn., P. crinitum var. cirratum E. Fourn., Podosemum ciliatum Kunth, P. tenuissimum J. Presl, and Schellingia tenera Steud. [ABSTRACT FROM AUTHOR]

We describe a new grass species, Agrostis swalalahos, endemic to several peaks in the northwestern Coast Range of Clatsop County, Oregon, U.S.A. [ABSTRACT FROM AUTHOR]

Premise of research. Geothermal areas create living conditions strikingly different from their surroundings, providing opportunities for studying organisms' thermal adaptations and responses to climate warming. However, the origins of geothermal organisms are poorly known, limiting our ability to design and interpret experimental studies. To address this, we tested whether geothermal populations of Agrostis (Poaceae) in Iceland represent a single lineage (clade) and, if so, whether that lineage originated in adjacent, nonthermal areas or elsewhere. Methodology. We studied the phylogeography of A. stolonifera and A. vinealis from geothermally heated and nonheated areas in Iceland, using whole plastome data and Bayesian and likelihood phylogenetic analyses. Having identified an exclusively geothermal clade for A. stolonifera , we performed a common-garden experiment to test for heritable phenotypic differences between geothermal and nonthermal plants. Pivotal results. At least two lineages of A. stolonifera have colonized Iceland independently, one being exclusively geothermal and the other exclusively nonthermal. The geothermal lineage is phylogenetically isolated, and its geographical origin could not be determined. Grown in a common garden, geothermal A. stolonifera produced significantly shorter stolons than nonthermal plants. In contrast, geothermal A. vinealis did not form a clade. Instead, all Icelandic A. vinealis formed a clade with nonthermal A. vinealis from outside of Iceland, plus geothermal A. rossiae and A. scabra. Conclusions. We demonstrate the existence of an exclusively geothermal lineage of A. stolonifera , which also shows heritable phenotypic differences, but not of A. vinealis. These contrasting findings possibly reflect different growth forms and life histories. Our results provide a phylogenetic hypothesis to be tested with nuclear data and a framework for future experimental studies, highlighting the importance of a historical perspective for understanding the peculiar plant communities that thrive in geothermal areas. Finally, our results suggest A. vinealis is in need of taxonomic revision. [ABSTRACT FROM AUTHOR]

Stress‐induced accumulation of ethylene exacerbates drought damages in plants and suppressing stress induction of ethylene may promote plant tolerance to drought stress. The objective of this study was to investigate the effects of endophytic bacteria (Paraburkholderia aspalathi) with 1‐aminocyclopropane‐1‐carboxylic acid (ACC) deaminase enzymes in suppressing ethylene production on plant tolerance to drought stress and post‐stress recovery and the underlying physiological mechanisms of P. aspalathi‐regulation in creeping bentgrass (Agrostis stolonifera L.). A novel strain of P. aspalathi, "WSF23," with ACC deaminase activity was used to inoculate the roots of creeping bentgrass plants (cv. "Penncross") subjected to drought stress for 35 days and rewatered for 15 days (post‐stress recovery) in controlled‐environment growth chambers. Inoculation with WSF23 bacteria resulted in an increased number of tillers, tillering production rate, root viability, and root growth (quantified in length, surface area, volume, and dry weight) during drought stress or rewatering. Inoculation of plants with WSF23 bacteria increased cytokinin (CK) (c‐Zeatin and tZ‐riboside) and jasmonate (JA‐Ile) content and reduced ACC and abscisic acid (ABA) content in roots during drought or rewatering. Sugar accumulation in crowns was promoted by inoculation during drought stress. The differential changes in ACC, CK, ABA, and JA‐Ile and sugar accumulation due to the bacterial inoculation could contribute to ACC deamination bacteria‐improved drought tolerance and post‐stress recovery in terms of tiller production and root proliferation and elongation in creeping bentgrass. Core Ideas: Plant growth promoting rhizobacteria (PGPR) can help to improve drought tolerance in cool season turfgrass.A novel strain of ACC deaminase producing Paraburkholderia aspalathi bacteria was used to inoculate the roots of creeping bentrgrass to modulate stress‐induced ethylene production.Changes in hormone and sugar metabolism influenced tiller development and root growth to improve drought stress tolerance and post‐drought recovery. [ABSTRACT FROM AUTHOR]

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The long-term influence of several living mulches on apple tree growth, nutrient status, yield, and fruit quality concerning the year of cover crop sowing in tree rows was evaluated in the Lower Silesia region in the southwestern part of Poland. The estimation was conducted in six apple tree 'Ligol' populations differentiated by the rootstock: M.26, M.9, P 60, P 2, P 16, and P 22. In experiment no. 1, one-year-old nursery stock was planted, and perennial living mulches were sown: colonial bent grass (Agrostis vulgaris With.) and white clover (Trifolium repens L.) in the same year and blue fescue (Festuca ovina L.) in the following year. In experiment no. 2, which involved two-year-old stock, the sowing of blue fescue was delayed until the second, third, fourth, and fifth years following orchard planting. The presence of the cover crop significantly affected young tree growth when one-year-old trees were planted. The sowing of the living mulch in the first or the second year after tree planting led to a significant reduction in the cumulative yield obtained from the young trees. The living mulch improved the red coloration of the fruit skin in the young orchard, but it caused a reduction in the mean fruit weight and size. However, it also contributed to decreased nitrogen concentration in the leaves of the apple trees, the tree tolerance to living mulch increased as the orchard aged. A choice of semidwarf rootstock, postponed sowing of cover crop, and high-quality nursery stock were recognized as the most important factors for fostering apple tree tolerance to living mulches in tree rows. [ABSTRACT FROM AUTHOR]

Agrostis capillaris L. (syn. A. tenuis Sibth.) is a perennial herbaceous, hemicryptophyte, native to Romania, distributed frequently from oak to subalpine levels. The circumpolar world distribution shows that the native range is quite extensive and can become adapted to a wide range of other habitats. Still, the literature review showed that in many countries, this species is introduced in grasslands as fodder for animals, as a sports turf and lawn species, and might be invasive in other countries replacing the native species from pastures and other grassland types. A. capillaris might be used as a hyper-accumulator, improving grassland quality; it provides economic value, social benefit, and environmental services. [ABSTRACT FROM AUTHOR]

Abstract In recent years the quest for a circular economy approach and the upcycling of secondary raw materials have been pushed in the global political agenda. Increased interest has been taken by the recovery of materials from sludges, brines, contaminated waters and other media, all included in the larger umbrella identified as “low-grade” mineralisation. Contaminated soils have an interesting role in this process, and various methodologies have been developed using chemical, bacteriological and pyrometallurgical cleaning procedures. However, these procedures all involve the movement of high volume of materials and the disruption of the industrial landscape; furthermore, they often require the use of hazardous solvents and high energy processes. This work proposes to identify less impactful methods aimed at the recovery of metals from mining areas while preserving the landscape and avoiding environmental impacts such as the increase of CO2 for transport and increase hazard through use of solvents, this takes particular importance in areas of industrial heritage status. In particular, this work focuses on the use of Agrostis tenuis, an autochthonous species in mining areas of the UK, as a “mining tool” for the removal of lead. The selection of this plant is due to its visually non-invasive nature, as the plant is already present in these areas, it doesn’t grow above 10/15 cm and it also grows very fast and can be easily harvested with existing agricultural equipment. The experiments and results presented in this paper indicate: (1) Agrostis Tenuis shows the ability to adjust to contamination and increase its accumulation capacity; (2) the metal collected by the plant is fully transposed in the aerial part of the plant in a stable compound form and can consequently be harvested and further processed.

Colonial bentgrass (Agrostis capillaris) is a tetraploid rhizomatous bentgrass that generally exhibits improved resistance to the important fungal disease dollar spot and has more tolerance to water‐deficit stress than the more widely grown creeping bentgrass (Agrostis stolonifera). Interspecific hybridization between these two species is possible and efforts to understand the genetic mechanisms of enhanced biotic and abiotic stress resistance in colonial bentgrass are proceeding. To gain a better understanding of the level of genetic diversity in cultivated colonial bentgrasses and to determine if genotypes with improved interspecific hybridization potential can be identified, nine colonial bentgrass cultivars and one creeping bentgrass cultivar were screened with 48 colonial bentgrass‐derived simple sequence repeat markers. Twenty‐one primer pairs were found to produce reliable amplification, and these markers were scored using high‐resolution melt analysis to generate haplotypes that were used to evaluate cultivar relationships. The nine colonial bentgrass cultivars could be placed into two groups and overall showed limited levels of diversity. The creeping bentgrass cultivar was distinct and individual genotypes within each species exhibited haplotypes more common in the alternate species, suggesting that these markers may be useful for selecting genotypes with enhanced interspecific hybridization potential. Core Ideas: The use of SSR loci with high‐resolution melt analysis and haplotype scoring is an effective method for assessing the genetic diversity of outcrossing grasses.The colonial bentgrass cultivars tested seperated into only two groups indicating that additional genetic diversity could enhance breeding efforts.The SSR haplotypes may help identify germplasm with enhanced interspecific hybidization potential. [ABSTRACT FROM AUTHOR]

Cultivation is commonly used to improve or maintain soil physical properties and reduce organic matter (OM) of golf putting greens. Surface disruption after cultivation is a major concern of golf course superintendents. Less invasive cultivation techniques are increasingly practiced, but there is limited research examining their effectiveness. This study was conducted to investigate the annual effect of air‐injection cultivation (AIC) and sand‐injection cultivation (SIC) alone or in combination with hollow‐tine cultivation (HTC) on soil moisture content, surface firmness, water infiltration rate, OM content, and soil oxygen (O2). The experiment was conducted over 2 years on a sand‐based putting green located at the Oklahoma State University Turfgrass Research Center in Stillwater, OK. HTC alone or in combination with AIC or SIC reduced soil moisture content, reduced surface firmness, and increased infiltration rates. Neither SIC nor AIC affected soil moisture, surface firmness, and infiltration rate, compared to the untreated control. AIC did not increase soil (O2) concentration, compared to the untreated control. Results suggest annual cultivation programs should not rely strictly on SIC or AIC, but these alternative practices may be useful supplements to HTC. Core Ideas: Hollow‐tine cultivation (HTC) affects soil moisture, surface firmness, organic matter, and infiltration rate.Air‐injection cultivation (AIC) and sand‐injection cultivation (SIC) alone did not affect soil moisture, surface firmness, and infiltration rate.Combining HTC with AIC and SIC increased the infiltration rate over HTC.SIC and AIC could be useful supplements to HTC. [ABSTRACT FROM AUTHOR]

Facilitation is an interaction where one species (the benefactor) positively impacts another (the beneficiary). However, the reciprocal effects of beneficiaries on their benefactors are typically only documented using short‐term datasets. We use Azorella selago, a cushion plant species and benefactor, and a co‐occurring grass species, Agrostis magellanica, on sub‐Antarctic Marion Island, comparing cushion plants and the grasses growing on them over a 13‐year period using a correlative approach. We additionally compare the feedback effect of A. magellanica on A. selago identified using our long‐term dataset with data collected from a single time period. We hypothesized that A. selago size and vitality would be negatively affected by A. magellanica cover and that the effect of A. magellanica on A. selago would become more negative with increasing beneficiary cover and abiotic‐severity, due to, e.g. more intense competition for resources. We additionally hypothesized that A. magellanica cover would increase more on cushion plants with greater dead stem cover, since dead stems do not inhibit grass colonization or growth. The relationship between A. magellanica cover and A. selago size and vitality was not significant in the long‐term dataset, and the feedback effect of A. magellanica on A. selago did not vary significantly with altitude or aspect; however, data from a single time period did not consistently identify this same lack of correlation. Moreover, A. selago dead stem cover was not significantly related to an increase in A. magellanica cover over the long term; however, we observed contrasting results from short‐term datasets. Long‐term datasets may, therefore, be more robust (and practical) for assessing beneficiary feedback effects than conventional approaches, particularly when benefactors are slow‐growing. For the first time using a long‐term dataset, we show a lack of physical cost to a benefactor species in a facilitative interaction, in contrast to the majority of short‐term studies. [ABSTRACT FROM AUTHOR]

Creeping bentgrass (Agrostis stolonifera L.) is a turfgrass species that is widely used on golf courses throughout the United States. In field settings, plants are often subjected to more than one stress at a time, and studying stresses independently is likely insufficient. Stresses, such as heat stress and salt stress, can affect plant hormone levels and, in turn, plant hormone levels can affect how well the plant tolerates stress. The objectives of the experiments were to determine if the levels of heat stress and salt stress used would be detrimental to creeping bentgrass health, and if applying plant growth regulators could improve plant health during stress. During the first experiment, creeping bentgrass was transplanted to hydroponics systems in two different growth chambers. One chamber was set to have day and night temperatures of 35 °C and 30°C (heat stress), respectively, and the other had day and night temperatures of 25 °C and 20°C, respectively. Within each chamber, one block received a 50 mM NaCl treatment (salt stress) and the other did not (control). The stress treatments were applied for 14 days. Results of the first experiment indicated that the treatments were sufficient to negatively affect creeping bentgrass growth and health as indicated by fresh shoot and root weights, tillering, electrolyte leakage, and total chlorophyll content (TCC). There were significant interactions of temperature x salt level detected for shoot and root weights and electrolyte leakage. Plants that were exposed to both heat stress and salt stress were more negatively affected than plants exposed to either heat stress or salt stress alone for all metrics except for tillering. The presence of salt reduced tillering regardless of the temperature regimen. During the second experiment, plants were treated the same, but the plant growth regulator (PGR) treatments were also applied. The PGR treatments consisted of two different gibberellic acid (GA) synthesis inhibitor products, 2,4-dichlorophenoxyacetic acid, two different rates of aminoethoxyvinylglycine (AVG), an ethylene synthesis suppressor, and plants that were not treated with the PGR. In addition to the measurements of plant health and growth, dry shoot and root weights were measured. For the TCC, there was a two-way interaction between temperature x PGR treatment. For electrolyte leakage, there was a three-way interaction between temperature x salt level x PGR treatment. Combined heat stress and salt stress negatively affected all plants regardless of PGR treatment, but there were differences between PGR treatments. Plants treated with AVG exhibited improved health and growth compared with the other PGR treatments. These plants had the highest shoot and root masses. Plants treated with GA synthesis inhibitors had the lowest shoot and root masses as well as the lowest TCC when subjected to stress. [ABSTRACT FROM AUTHOR]

Today, bridging precision agriculture (PA) with farm management is a high priority. To respond to this challenge, a precision fertilization service for extended crops, namely ‘PreFer’ (developed by 'Ecodevelopment' enterprise), was embedded as a new module in a cloud-based farm management information system (FMIS), namely ‘ifarma’ (developed by 'Agrostis' enterprise). The new PreFer module preserves the full potential of the original service methodology, while taking advantage of all fundamental functionalities of the ifarma platform. PreFer as a service uses a GIS to store and process the farmers’ geodatabases, which are fed from multiple sources, such as soil surveys, satellite data, yield monitors, etc. This GIS is also used to feed the machine learning algorithms of ‘PreFer’ with the required data to produce the prescription maps for both broadcasting and topdressing fertilizations. Then, all tables and maps are transferred from the GIS to the platform upon their production, thus becoming immediately available to the farmers. The ‘ifarma/PreFer' module was tested during the 2022 cultivation season, showing that fully meets farmers' requirements. This work also indicates that synergies like this are more than necessary to create added-value in commercial precision agriculture.