Hard fescue ( Festuca brevipila ) is a fine‐leaved cool‐season turfgrass and is well adapted for low‐maintenance areas, such as home lawns, parks, and roadsides. Breeding for improved disease resistance is a major objective in utilizing hard fescue under low‐input management. The Epichlöe festucae endophyte‐mediated dollar spot ( Clarireedia jacksonii ) resistance and its mechanism have been well‐documented in strong creeping red fescue ( F. rubra subsp. rubra ). However, little is known about dollar spot resistance in hard fescue. The objectives of this research were to (1) understand the inheritance of dollar spot resistance in hard fescue and determine the reciprocal effects by performing a diallel cross between three resistant endophyte‐containing and three susceptible endophyte‐free parents and (2) confirm the role of E. festucae endophyte in dollar spot resistance by artificially inoculating hard fescue with the endophyte (ME+) and comparing ME+ plants to their genetically identical counterparts without the endophyte (E‒) under dollar spot pressure. The highly significant maternal effect from the diallel cross experiment demonstrated that the dollar disease resistance is maternally inherited in hard fescue and linked with the maternal inheritance of the E. festucae endophyte. The greenhouse study further confirmed that the presence of E. festucae endophyte significantly reduced dollar spot in hard fescue. Understanding this endophyte effect on maternal inheritance of dollar spot resistance will enable more efficient breeding and selection of plant materials to use in the development of improved dollar spot resistant cultivars in hard fescue.

The effects that mycobiomes have on physiological traits in turfgrasses are poorly understood. Drought tolerance, an economically and ecologically important trait, can be influenced by symbiotic fungi. In this two-year study, we evaluated the mycobiome associated with tall fescue exposed to prolonged periods of drought stress in a rainout shelter. Twelve plants, comprising six sets of half-sibs (progenies having one parent in common), one exhibiting a drought-tolerant phenotype and the other a drought-susceptible phenotype, were selected for analysis each year. The mycobiomes associated with the shoot, root, and rhizosphere soil were evaluated for each tall fescue half-sib pair using both short-read Illumina MiSeq and long-read Oxford Nanopore Technology (ONT) MinION sequencing pipelines. Both platforms sequenced portions of the fungal nuclear ribosomal RNA genes. The Illumina MiSeq sequenced the internal transcribed spacer region (ITS, 600 bp), while the ONT MinION covered the small subunit, ITS, and partial large subunit (4,600 bp). Both sequencing pipelines revealed that the mycobiomes associated with the roots, shoots, and soil were significantly different. The ONT MinION pipeline identified more diverse fungal lineages and had higher taxonomic resolution than the Illumina pipeline. Our results also indicated that root pathogens may play a more important role than endophytic or mycorrhizal symbionts in tall fescue drought stress tolerance.

High summer temperatures coupled with a lack of precipitation can lead to a drastic deterioration in overall turf quality. Limited water supply and heavy restrictions on its use in the turfgrass industry significantly limit the ability of turfgrass managers to maintain cool-season turfgrasses during summer months. The objective of this study was to evaluate the heritability of summer stress tolerance in tall fescue (Festuca arundinacea Schreb.). Six distinct tall fescue genotypes, three summer stress tolerant (TF-5, TF-6, and TF-10) and three summer stress sensitive (TF-2, TF-15, and TF-21), were used as parents in a full diallel cross and a polycross block. Individual progeny plants from these two populations, along with parental clones, were evaluated in the field in a space-plant nursery located at the Rutgers Adelphia Plant Science Research and Extension Farm in Freehold, New Jersey, USA. The field was unirrigated during the summers and visually rated for overall performance under summer stress. Narrow-sense heritability was estimated to be 0.637 using two-year combined data from the diallel population, and a gain from selection of 59% can be expected using a 5% selection intensity. General combining ability (GCA) effect was statistically significant in both years and accounted for more variance than specific combining ability (SCA). The results of this study suggest that additive gene action is a major component in the inheritance of summer stress tolerance in tall fescue and that recurrent selection should be an effective breeding strategy for improving summer stress tolerance in tall fescue.

Growing livestock populations have intensified the potential for detrimental effects of grazing on grassland soils globally. Grazing management techniques can mitigate these effects but they are livestock-specific and studies on horse grazing are rare. The objective of this work was to compare the effects of rotational grazing (i.e., livestock graze sub-sections of a pasture in sequence) with the continuous approach to grazing on (1) rates of water infiltration (i) at slightly negative pressure potentials (h, - 15, - 10, - 5, - 3.5, - 1 hPa), (2) saturated hydraulic conductivity (Ksat), and (3) bulk density (BD). At a site in New Jersey, USA, one pair of pastures was managed with rotational grazing while another pair experienced continuous grazing. Twelve Standardbred mares were grazed for two years at a stocking rate of 0.52 horses ha- 1. Over that period, i (n = 79, each at 5 h values) and BD (n = 154, from depth ranges 0-10 and 30-40 cm) were measured multiple times and Ksat values were derived from infiltration measurements. Also, the standardized precipitation-evapotranspiration index (SPEI) was calculated with meteorological data from a nearby weather station. We found that: (1) i values inclusive of the largest pores tested (h = - 1 hPa) were greater in rotationally-vs. continuously-grazed fields (geometric means & PLUSMN; GSE were 80.2 & PLUSMN; 1.15 and 42.3 & PLUSMN; 1.13 cm d- 1, respectively), (2) Ksat values were consistent with those of infiltration at h = - 1 hPa but were too variable to isolate the effect of pasture management, and (3) near-surface BD was similar under rotational and continuous grazing (arithmetic means & PLUSMN; SE were 1.32 & PLUSMN; 0.02 and 1.37 & PLUSMN; 0.02 Mg m- 3, respectively). Further, during periods of water surplus (i.e., when SPEI was positive), infiltration was strongly reduced in the smaller soil pores (h = - 10 and - 15 hPa) of the rotationally-grazed fields. This reduction was likely the result of pore colonization and blockage by pasture grass roots growing in these fields. This study suggests that rotational management allows for a larger macropore system than continuous grazing, which could lead to a reduction of water deficits and contribute to the sustainability of grazed ecosystems, with positive effects accruing through time.

Gray leaf spot, caused by the fungal pathogen Pyricularia oryzae , is a widespread and destructive foliar disease of turfgrasses in the United States. Characteristic gray leaf spot disease symptoms were observed on hard fescue ( Festuca brevipila Tracey) turf in New Jersey during October 2018. Prior to this observation, P. oryzae had not been documented as a pathogen of F. brevipila . Therefore, this study was conducted to determine if P. oryzae was the cause of the observed gray leaf spot disease symptoms. Morphological assessments and molecular analyses identified fungal isolates as the potential incitant from symptomatic F. brevipila turf as P. oryzae . Two isolates of P. oryzae (D300452 and 181001P12) and two F. brevipila cultivars (‘Beacon’ and ‘Reliant IV’) were used in growth chamber studies to fulfill Koch’s postulates for pathogenicity. Inoculations were carried out using conidial suspensions at 4 × 10 4 conidia ml − 1 concentration. Disease symptoms were observed 7 d post-inoculation for both isolates on both cultivars. Koch’s postulates were fulfilled by morphological evaluations and DNA sequencing of the reisolated fungi. This study confirms that P. oryzae is the causal agent of gray leaf spot disease on F. brevipila . Given the historical significance of gray leaf spot disease in other turf species, this study suggests that gray leaf spot could be a major concern for managing F. brevipila turf in the future.

There is a need to identify turfgrass species and mixtures for golf course fairways that can be managed sustainably with reduced fertility, pesticides, and irrigation. The current study evaluated Agrostis stolonifera L. (creeping bentgrass [AST]), Agrostis capillaris L. (colonial bentgrass [ACP]), Agrostis canina L. (velvet bentgrass [ACN]), Festuca rubra L. ssp. commutata Gaudin (Chewings fescue [FRC]), Festuca brevipila Tracey (hard fescue [FBP]), and Festuca rubra L. ssp. littoralis (G. Mey) Auquier (slender creeping red fescue [FRL]) planted as monostands and in mixtures to determine the ideal choice for low maintenance fairway management. Plots were established in the fall of 2014 in a randomized complete block design with three replications. Turf quality and disease resistance were evaluated visually from 2015–2018. Divots were mechanically created during the growing seasons of 2017 and 2018 and evaluated visually for initial divot injury and recovery every two weeks. Monostands and mixtures of ACN had the best turf quality and least brown patch (caused by Rhizoctonia solani Kühn) but took longer to recover from divots. A. capillaris monostands and mixtures exhibited above average turf quality but were more susceptible to brown patch disease. Compared to all other entries, monostands and mixtures of AST had the lowest turf quality and most dollar spot (caused by Clarireedia jacksonii C. Salgado, L.A. Beirn, B.B. Clarke, & J.A. Crouch sp. nov.). Festuca L. spp. (fine fescue spp.), when mixed with improved ACP cultivars such as ‘Puritan’ and ‘Capri’, exhibited above average turf quality but had below average performance in monostands or when combined with older ACP cultivars such as SR 7100. Divot resistance and recovery were variable between years but the FRL cultivar Shoreline and most FRC cultivars recovered quickly in both years, while ACP cultivar Capri and FBP cultivar Beacon were slow to recover in both years. Most species and mixtures were comparable and, in some cases, better than AST for divot recovery indicating that the alternative species tested in this study could provide sustainable turfgrass management on golf course fairways.

Anthracnose, caused by the fungal pathogen Colletotrichum cereale Manns sensu lato Crouch, Clarke & Hillman, can be a damaging disease on many cool-season turfgrasses; however, it has not been reported as an aggressive pathogen on fine fescue species ( Festuca spp.). Symptoms and signs associated with anthracnose disease were observed in fine fescues on the Rutgers University Plant Science Research and Extension Farm in Adelphia, NJ, in Jun 2014. The objectives of this study were to identify the causal agent, determine if the isolate of C. cereale (FF1A) obtained from symptomatic Chewings fescue ( Festuca rubra L. ssp. commutata Gaudin) plants was pathogenic to Chewings fescue and hard fescue ( F. brevipila Tracey) turfs, and whether cultivars and accessions collected from Europe varied in disease susceptibility. Pathogenicity of this fine fescue isolate was evaluated using four Chewings fescue and four hard fescue cultivars or accessions in a growth chamber. Disease symptoms were first observed at 5 days post-inoculation, and evaluations continued to 17 days post-inoculation. Infection was confirmed by morphological evaluations, re-isolation from symptomatic tissues, and real-time polymerase chain reaction (PCR). Three noncommercial accessions (two Chewings fescues and one hard fescue) were very susceptible to the fine fescue C. cereale FF1A isolate, whereas ‘Sword’ and ‘Beacon’ hard fescues exhibited low susceptibility. In addition, an isolate of C. cereale (HF217CS) from annual bluegrass [ Poa annua L. f. reptans (Hausskn) T. Koyama] was included, and our data demonstrated that this isolate was also able to infect Chewings fescue and hard fescue. This study confirmed that C. cereale can be a damaging pathogen of fine fescues, and that breeding for resistance to anthracnose should be considered when developing new cultivars.

Rain-out shelters provide an effective tool to establish controlled water-stress environments by excluding undesired rain events and have been widely used in the selection and breeding of cool-season turfgrass for improved drought tolerance. However, the efficiency of recurrent selection using rain-out shelters has seldomly been investigated. In this study, we documented the selection process of tall fescue in one cycle of recurrent selection, compared the drought tolerance of two consecutive generations and estimated selection gain of tall fescue using rain-out shelters. Depending on days of drought, relative selection gain ranges from -4.20% to 3.60%, indicating small and unstable improvement from the parental generation. A subsequent analysis of experimental data using Bayesian mixed linear model revealed low narrow-sense heritability estimations (0.18 for parental generation and 0.08 for progeny generation), providing an explanation for this observation.

Warm-season grasses (WSG) incorporated into traditional cool-season rotational grazing systems to increase summer yields are typically established in monoculture in separate pasture areas. Few studies have evaluated alternative interseeded establishment of WSG, despite potential benefits for improving biodiversity and land-use efficiency. The objective of this study was to determine the impact of establishment method (monoculture vs. interseeded) on crabgrass pasture forage yield, nutritive value, and preference under equine grazing. Three adult standard-bred mares grazed two main plots on two consecutive days (8 hr/d) for three grazing events in 2019: Jul 28/29 (GRAZE 1), Aug 20/30 (GRAZE 2), Oct 1/2 (GRAZE 3). Each main plot contained four replicates of three treatments: mixed cool-season grass (CSG); Quick-N-Big crabgrass (CRB) [Digitaria sanguinalis (L.) Scop.] interseeded into existing cool-season grass (INT), and CRB established as a monoculture (MON). The cool-season grass mix included Inavale orchardgrass [Dactylis glomerata (L.)], Tower tall fescue [Lolium arundinaceum (Schreb.) Darbysh.], and Argyle Kentucky bluegrass [Poa pratensis (L.)]. Herbage mass (HM) and sward height (SH) were measured prior to each grazing event and samples were collected (0800-1000 h) for chemical composition analysis. Observed grazing time (GT) in each sub-plot as determined by 5-min scan sampling was utilized as marker of horse preference. Forage HM was greater in MON (8043 +/- 1220 kg/ha) than CSG (5001 +/- 1308 kg/ha; P = 0.003), with a trend for greater total HM in MON vs. INT (6582 +/- 1220 kg/ha: P = 0.06), but HM did not differ between INT and CSG. The SH was also greatest for MON (28 +/- 1.11; INT: 23.6 +/- 1.11; CSG: 19.7 +/- 1.37 cm; P < 0.003). Forage nutrients (digestible energy and crude protein) were largely similar across treatments and met requirements of horses at maintenance. Horse GT was lower in MON (22.6 +/- 3.77 min/sub-plot) than in INT (31.9 +/- 3.79 min/sub-plot; P = 0.003) and there was a trend for lower GT in MON vs. CSG (29.9 +/- 4.17 min/sub-plot: P = 0.07). These results indicate interseeding CRB would not effectively increase yields of traditional cool-season grass equine rotational grazing systems and would not supply similar levels of summer forage provided by monoculture establishment. Results of this study also suggest horses may prefer cool-season grass pasture forage over warm-season crabgrass.

Red thread, caused by [ Laetisaria fuciformis (Berk.) Burds.], is a common disease on many cool-season and some warm-season grasses throughout the world. Low reproducibility of experiments under both natural and artificial infection and inadequate understanding of the underlying genetics have limited the selection of turfgrass for resistance to red thread. This study investigated red thread prevalence of tall fescue ( Festuca arundinacea Schreb.) populations in two locations over multiple years, estimated disease prevalence in a broad collection of tall fescue populations, and calculated heritability of disease prevalence with two different experimental designs. Collections from Albania and Romania, as well as those that were recently backcrossed to adapted germplasm, were more susceptible to red thread compared with the rest of the populations, highlighting the importance of selection efforts against red thread disease in tall fescue. Narrow-sense heritability (0.52, 0.74, and 0.48) estimated from different experimental designs were all in the range of moderate to high, indicating a large proportion of additive genetic variance in red thread prevalence among tall fescue populations. Hence, prevalence of red thread in tall fescue can be effectively reduced through selection and breeding. This is also the first report documenting the efficacy of family selection in reducing red thread prevalence in tall fescue.

Warm-season grasses have been suggested as alternative low non-structural carbohydrate (NSC) pasture forages. The purpose of this study was to evaluate nutrient composition and diurnal changes in soluble carbohydrates for the warm-season annual 'Quick-N-Big' crabgrass [CRB; Digitaria sanguinalis (L.) Scop.] and the warm-season perennial 'Wrangler' bermudagrass [BER; Cynodon dactylon (L.) Pers] in comparison to mixed cool-season grass [CSG; 'Inavale' orchardgrass (Dactylis glomerata [L.]), 'Tower' tall fescue (Lolium arundinaceum [Schreb.] Darbysh.), and 'Argyle' Kentucky bluegrass (Poa pratensis [L.])]. Samples were collected at 4-hour intervals over 3 d when each forage reached the boot stage of maturity. Digestible energy was greatest for CSG (2.29 ± 0.34 Mcal/kg) and lowest for BER (2.13 ± 0.34 Mcal/kg), while crude protein was lowest for CSG (16.1 ± 0.29%) and neutral detergent fiber was greatest for BER (60.0 ± 0.41; P ≤ .0008). Non-structural carbohydrates were greater for CSG (17.6% ± 0.26%) compared to BER (10.6% ± 0.26%) or CRB (10.9% ± 0.26%; P < .0001). Overall, NSC was greatest in the afternoon and evening (14.5-14.9 ± 0.60%) and lowest in the early morning (11.2-11.4 ± 0.60%; P ≤ .04), but diurnal variation was most pronounced in CSG versus either Warm-season grasses. Results of this study provide needed data on nutritional composition of CRB and BER and demonstrate that these grasses may serve as pasture forages for horses where NSC intake is of concern. Results also support recommendations for restricting grazing to early morning to limit NSC consumption, particularly in CSG pastures.

Incorporating warm-season grasses (WSG) into traditional cool-season (CSG) rotational pastures has been utilized to increase summer forage available for grazing cattle. The aim of this study was to evaluate the impact of this practice on yield and nutritive value of horse pastures. We hypothesized WSG incorporation would increase summer pasture yield, while being lower in non-structural carbohydrates (NSC). Two 1.5 ha rotational systems (6–0.25 ha sections/system) were utilized: a control system (CON) with all sections containing an established CSG mix (Kentucky bluegrass, orchardgrass, and tall fescue), and an integrated system (IRS) [3 CSG sections (CSG-IRS) and 3 Quick-N-Big crabgrass (CRB-IRS)]. Three horses per system grazed across 3 periods: EARLY (mid-May to mid-Jul), SLUMP (mid-Jul to mid-Sep), and LATE (mid-Sep to mid-Nov). Horses were confined to dry lots if sufficient pasture forage was not available. Before each rotation, herbage mass (HM) was measured and forage samples collected (0800–1000) with nutrients analyzed by wet chemistry. Grazing days were tracked to calculate carrying capacity (CC). Data were analyzed by ANOVA and means separated by Tukey's method in R. Over the full grazing season, IRS provided pasture access for 123 d, while CON supported grazing for 104 d (69% and 59% of total). Total HM per section did not differ during EARLY grazing when CRB was not available (CSG-IRS: 2537 ± 605; CSG-CON: 3783 ± 856 kg/ha), but CC was greater in CSG-IRS (220 ± 37 horse d/ha) than in CSG-CON (92 ± 26 horse d/ha; P = 0.03). In SLUMP grazing, both HM and CC were greater in CRB-IRS (HM: 4758 ± 698 kg/ha; CC: 196 ± 31 horse d/ha) than either CSG-IRS (HM: 1086 ± 698 kg/ha; CC: 32 ± 31 horse d/ha) or CON (HM: 970 ± 493 kg/ha; CC: 46 ± 22 horse d/ha; P < 0.02). While HM did not differ by section type in LATE grazing (1284 ± 158 kg/ha), CC was greater in CON (84 ± 9 horse d/ha) vs CRB-IRS (32 ± 13 horse d/ha; P = 0.03) and CSG-IRS (40 ± 13 horse d/ha; P = 0.06). During the SLUMP, water-soluble carbohydrates (WSC) were lower in CRB-IRS (4.46 ± 0.80%) than CSG-CON (7.92 ± 0.90%; P < 0.04), but not CSG-IRS (5.93 ± 1.04%); however, non-structural carbohydrates (NSC) did not differ (7.05 ± 0.62%). There were no differences in either WSC (6.46 ± 0.54%) or NSC (7.65 ± 0.54%) by section type in LATE grazing. These results demonstrated increased summer horse pasture yield through integrated grazing, but further research is needed to improve late-season production. Additionally, integrated grazing provided lower WSC to grazing horses, but NSC remained below 10% for all pasture sections.

Integration of warm-season grasses into traditional cool-season pastures can increase summer forage for grazing cattle. The aim of this study was to determine impacts of this practice on yield and nutrient composition of equine rotational pasture systems as well as horse body condition. Two 1.5 ha rotational systems (6 to 0.25 ha sections/system) were evaluated: a control system (CON) (all sections mixed cool-season grass [CSG-CON]) and an integrated rotational grazing system (IRS) (three CSG sections [CSG-IRS] and three Quick-N-Big crabgrass [Digitaria sanguinalis (L.) Scop.; CRB-IRS]). Three horses per system grazed in three periods: EARLY (mid-May to mid-July), SLUMP (mid-July to mid-September), and LATE (mid-September to mid-November). Herbage mass (HM) was measured prior to each rotation and samples were collected (0800 to 1000 h) for nutrient analysis. Grazing days were tracked to calculate carrying capacity (CC). Horse condition measures were assessed monthly. Over the full grazing season, 9,125 kg of forage was available for grazing in IRS versus 6,335 kg in CON. The CC was 390 horse d for IRS, while only 276 horse d for CON. Total HM/section did not differ during EARLY when CRB was not available (CSG-IRS: 2,537 ± 605; CSG-CON: 3,783 ± 856 kg/ha), but CC was greater in CSG-IRS (220 ± 37 horse d/ha) than CSG-CON (92 ± 26 horse d/ha; P = 0.03). In SLUMP, both HM and CC were greater in CRB-IRS (HM: 4,758 ± 698 kg/ha; CC: 196 ± 31 horse d/ha) than CSG-IRS (HM: 1,086 ± 698 kg/ha; CC: 32 ± 31 horse d/ha) or CON (HM: 970 ± 493 kg/ha; CC: 46 ± 22 horse d/ha; P < 0.02). While HM did not differ by section type in LATE (1,284 ± 158 kg/ha), CC was greater in CSG-CON (84 ± 9 horse d/ha) versus CRB-IRS (32 ± 13 horse d/ha; P = 0.03) and CSG-IRS (40 ± 13 horse d/ha; P = 0.06). During SLUMP, water-soluble carbohydrates (WSC) were lower in CRB-IRS (4.46% ± 0.80%) than CSG-CON (7.92% ± 0.90%; P < 0.04), but not CSG-IRS (5.93% ± 1.04%); however, non-structural carbohydrates (NSC) did not differ (7.05% ± 0.62%). There were no differences in WSC (6.46% ± 0.54%) or NSC (7.65% ± 0.54%) by section type in LATE. Horses in IRS maintained a body condition score (BCS) of 5.78 ± 0.48, but BCS did not differ by system (CON: 6.11 ± 0.48). Thus, integrated grazing increased summer pasture yield and provided adequate nutrition to maintain horse condition, but further research is needed to improve late-season production. Integrated grazing may not, however, provide an advantage in limiting dietary NSC, as NSC remained low for all pasture sections.

Fine fescues (Festuca sp.) are a group of species that require fewer inputs, such as fertilizer, than other cool-season species managed for turf. They are adapted to infertile, acidic soils; shade; and drought. One area that poses additional challenges is the lack of weed control options for fine fescues during establishment from seed. Mesotrione is a herbicide that provides preemergence control of many broadleaf and grassy weeds, such as annual bluegrass (Poa annua), but is currently not labeled for use in fine fescues at seeding. The objectives of this research were 1) to use a recurrent selection technique to develop mesotrione-tolerant chewings fescue (Festuca rubra ssp. commutata), hard fescue (Festuca brevipila), and strong creeping red fescue (F. rubra spp. rubra); and 2) to conduct field trials to compare the new selections to commercially available cultivars and experimental lines not selected for tolerance to mesotrione. Progress was made after each of the three generations of recurrent selection. The top statistical grouping of entries for injury following application of mesotrione at the 8-oz/acre rate included all the third-generation (G3) hard fescues, all the G3 chewings fescues, and the G3 strong creeping red fescue STB1 Composite. After three generations, selections of hard, chewings, and strong creeping red fescues had equivalent or better tolerance to mesotrione than tall fescue (Festuca arundinacea) and kentucky bluegrass (Poa pratensis) cultivars, which are on the label for safe use at seeding. These new selections would provide turf managers an option to control weeds using mesotrione during seedling establishment of fine fescues.

Background and Aims Rhizomes are key organs for the establishment of perennial grass stands and adaptation to environmental stress. However, mechanisms regulating rhizome initiation and elongation under drought stress and during post-drought recovery remain unclear. The objective of this study is to investigate molecular factors and metabolic processes involved in drought effects and post-drought recovery in rhizome growth in perennial grass species by comparative transcriptomic and proteomic profiling. Methods Tall fescue (Festuca arundinacea) (B-type rhizome genotype, 'BR') plants were exposed to drought stress and re-watering in growth chambers. The number and length of rhizomes were measured following drought stress and re-watering. Hormone and sugar contents were analysed, and transcriptomic and proteomic analyses were performed to identify metabolic factors, genes and proteins associated with rhizome development. Key Results Rhizome initiation and elongation were inhibited by drought stress, and were associated with increases in the contents of abscisic acid (ABA) and soluble sugars, but declines in the contents of indoleacetic acid (IAA), zeatin riboside (ZR) and gibberellin (GA(4)). Genes involved in multiple metabolic processes and stress defence systems related to rhizome initiation exhibited different responses to drought stress, including ABA signalling, energy metabolism and stress protection. Drought-inhibition of rhizome elongation could be mainly associated with the alteration of GA 4 and antioxidants contents, energy metabolism and stress response proteins. Upon re-watering, new rhizomes were regenerated from rhizome nodes previously exposed to drought stress, which was accompanied by the decline in ABA content and increases in IAA, ZR and GA(4), as well as genes and proteins for auxin, lipids, lignin and nitrogen metabolism. Conclusions Drought-inhibition of rhizome initiation and elongation in tall fescue was mainly associated with adjustments in hormone metabolism, carbohydrate metabolism and stress-defence systems. Rhizome regeneration in response to re-watering involved reactivation of hormone and lipid metabolism, secondary cell-wall development, and nitrogen remobilization and cycling.

The objective of this study was to determine whether rotational grazing generates horse, pasture, or cost benefits over continuous grazing. The study established two replicates (1.57 ha each) of rotational (R; four grazing sections and a stress lot per replicate, where horses were fed a moderate quality grass hay at 2% of body weight when not grazing) and continuous (C) grazing systems (treatments). Twelve Standardbred mares were grazed for an overall stocking rate of 0.52 ha/horse (n = 3 in each pasture). Recommended management practices for each grazing system were followed for 27 mo including three grazing seasons. Samples were collected monthly between 0800 and 1000. Results were analyzed in SAS (V9.4) using mixed model repeated-measures analysis of covariance, chi-square tests of association, and two-sample t-tests. Alpha level was set at P < 0.05. The C horses were maintained on pasture for 100% of the study duration (844 d; August 1, 2014 to November 22, 2016), while R horses had access to pasture for approximately half of this time (408 ± 33 d). The average length of grazing bout per rotational grazing section during the grazing season increased numerically each year from 7.88 ± 0.76 d in 2014, 10.0 ± 0.61 d in 2015, and 10.9 ± 0.80 d in 2016. Average horse body condition score (BCS) and body fat differed by treatment, with C horses (BCS 6.3 ± 0.05, 17.9 ± 0.15% body fat) greater than R horses (BCS 5.9 ± 0.05, 16.8 ± 0.15% body fat). Both sward height and herbage mass were greater in R (11.8 ± 0.1 cm tall; 1,513 ± 41 kg/ha) than C pastures (6.9 ± 0.1 cm tall; 781 ± 35 kg/ha). The R pastures had higher proportions of vegetative and total cover, planted grasses (tall fescue and orchardgrass), and weeds but lower proportions of grass weeds (nonplanted grasses) and other (rocks, litter, bare ground, etc.) as compared with C pastures. Digestible energy, acid detergent fiber, and calcium were higher in R vs. C pastures; however, crude protein was lower in R vs. C pastures. There were no significant differences between treatments for average monthly amount of hay fed (C, 597 ± 34.1 vs. R, 659 ± 34.1 kg) or average monthly pasture maintenance cost (C, $17.55 ± 3.14 vs. R, $20.50 ± 3.14). This study is one of few replicated experiments comparing the effects of rotational and continuous grazing for horses on pasture quality, horse condition, and production costs. The results here support the recommendation of rotational grazing for production, environmental, and ecological purposes.

Turfgrass investigators have observed that plantings of grass seeds produced in moist climates produce seedling stands that show greater stand evenness with reduced disease compared to those grown from seeds produced in dry climates. Grass seeds carry microbes on their surfaces that become endophytic in seedlings and promote seedling growth. We hypothesize that incomplete development of the microbiome associated with the surface of seeds produced in dry climates reduces the performance of seeds. Little is known about the influence of moisture on the structure of this microbial community. We conducted metagenomic analysis of the bacterial communities associated with seeds of three turf species (Festuca rubra, Lolium arundinacea, and Lolium perenne) from low moisture (LM) and high moisture (HM) climates. The bacterial communities were characterized by Illumina high-throughput sequencing of 16S rRNA V3-V4 regions. We performed seed germination tests and analyzed the correlations between the abundance of different bacterial groups and seed germination at different taxonomy ranks. Climate appeared to structure the bacterial communities associated with seeds. LM seeds vectored mainly Proteobacteria (89%). HM seeds vectored a denser and more diverse bacterial community that included Proteobacteria (50%) and Bacteroides (39%). At the genus level, Pedobacter (20%), Sphingomonas (13%), Massilia (12%), Pantoea (12%) and Pseudomonas (11%) were the major genera in the bacterial communities regardless of climate conditions. Massilia, Pantoea and Pseudomonas dominated LM seeds, while Pedobacter and Sphingomonas dominated HM seeds. The species of turf seeds did not appear to influence bacterial community composition. The seeds of the three turf species showed a core microbiome consisting of 27 genera from phyla Actinobacteria, Bacteroidetes, Patescibacteria and Proteobacteria. Differences in seed-vectored microbes, in terms of diversity and density between high and LM climates, may result from effects of moisture level on the colonization of microbes and the development of microbe community on seed surface tissues (adherent paleas and lemmas). The greater diversity and density of seed vectored microbes in HM climates may benefit seedlings by helping them tolerate stress and fight disease organisms, but this dense microbial community may also compete with seedlings for nutrients, slowing or modulating seed germination and seedling growth.

Raw data of a 16S metagenomic analysis on the bacterial community associated with cool-season turf grass seeds. The data was generated by Illumina MiSeq platform.

Methiozolin is a new herbicide that controls annual bluegrass (Poa annua) in turfgrasses, but the differential tolerance levels of fine fescues (Festuca sp.) has received limited investigation. The objective of this study was to investigate the potential injury from methiozolin when applied to chewings fescue (Festuca rubra ssp. fallax), strong creeping red fescue (Festuca rubra ssp. rubra), and hard fescue (Festuca brevipila). Nine different fine fescue populations (14W2 Comp, Fairmont, and Survivor chewings fescue; FT345, Miser, and Fenway strong creeping red fescue; and 14H4 Comp, Stonehenge, and Oxford hard fescue) were sprayed with methiozolin at five different rates (0.42, 0.83, 1.25, 1.67, and 2.09 lb/acre) at four different application timings [4 weeks before seeding (WBS), 2 WBS, at seeding (AS), and 2 weeks after germination (WAG)]. Untreated controls were also included for each combination. Significant reduction in germination of fine fescue was observed when methiozolin was applied before emergence for all tested application rates. Methiozolin at 1.25, 1.67, and 2.09 lb/acre applied before or at the day of seeding led to complete inhibition of germination in all fine fescue species tested. It was less injurious compared with methiozolin applied at 2 WAG, although a reduction in the percentage of green cover and biomass was observed for application rates greater or equal to 0.83 lb/acre. The hierarchical ranking of species injury from high to low is as follows: hard fescue, chewings fescue, and strong creeping red fescue. A possible solution for annual bluegrass control in fine fescue species with methiozolin is multiple postemergence applications up to a maximum rate of 0.83 lb/acre. Turf managers need to make adjustments in methiozolin application rates and timings based on fine fescue species to maximize selectivity for annual bluegrass control.

Abstract Fine fescues (Festuca spp.) are cool-season grasses used in low-maintenance turf areas. Mesotrione is a PRE and early-POST herbicide used during establishment of most cool-season turfgrasses, excluding fine fescues. Currently, efforts are being made to breed for increased tolerance to mesotrione in fine fescues to enhance weed control during establishment. This study was conducted to evaluate the association of foliar and root uptake of [14C]mesotrione with the tolerance of three lines each of Chewings fescue [Festuca rubra ssp. commutata Gaudin; syn. F. rubra ssp. fallax (Thuill.) Nyman], hard fescue [Festuca trachyphylla (Hack.) Hack.], and strong creeping red fescue (Festuca rubra L. ssp. rubra) lines. From a rate-titration experiment, the hierarchical rank of species for mesotrione tolerance from highest to lowest was: hard > Chewings > strong creeping red fescue. The hierarchical rank of species for foliar uptake from highest to lowest was: Chewings > strong creeping red > hard fescue. Translocation of foliar-absorbed 14C was not associated with differential tolerance levels of the three species. Root absorption was comparable among species, but differences between lines were detected within the species. The most susceptible lines of Chewings and strong creeping red fescue exhibited greater root uptake than lines with greater tolerance. Hard fescue translocated the least amount of root-absorbed radioactivity to shoots, while Chewings and strong creeping red fescues were comparable.