Tall Fescue Cultivars Research Articles

Intake and Digestibility of Improved Selections of Tall Fescue and Orchardgrass Hays

ABSTRACTImproved cool‐season grass cultivars may add production potential to ruminant enterprises across the North–South transition zone. Quality among hays of ‘MaxQ’ (‘Jesup’ with novel endophyte), HM4 (‘HiMag’ with novel endophyte No. 4) and ‘Cajun’ (without endophyte) tall fescues [Lolium arundinaceum (Schreb.) Darbysh.] and ‘Persist’ orchardgrass (Dactylis glomerata L.) was evaluated. Forage was harvested in the flag‐leaf stage in three of 4 yr and a regrowth (late flag‐leaf to heads‐emerging stage) in 1 yr. Goats (four trials) consumed MaxQ, HM4, and Persist similarly (P = 0.12; mean = 2.49 kg 100−1 kg body weight [BW]) and Cajun least (P < 0.01; mean = 1.62 kg × 100−1 kg BW). Apparent digestibility was similar among tall fescues (P ≥ 0.07; mean = 609 g kg−1), but MaxQ and Cajun were greater than Persist (P ≤ 0.05; mean = 610 and 623 vs. 582 g kg−1). Digestible dry matter intake (DMI) was similar among MaxQ, HM4, and Persist (P ≥ 0.09; mean 1.49 kg 100−1 kg BW). Steers (three trials and Cajun not evaluated) consumed more Persist than MaxQ (P = 0.01; 2.40 vs. 2.14 kg 100−1 kg BW) or HM4 (P = 0.01; 1.98 kg 100−1 kg BW). MaxQ had greater apparent digestibility than HM4 (P = 0.01) or Persist (P = 0.04; 626 vs. 585 vs. 597 g kg−1, respectively) but digestible DMI of MaxQ and Persist was similar (P = 0.12; mean = 1.39 kg 100−1 kg BW). Improved tall fescue cultivars, with novel endophyte, offer the ruminant producer a cool‐season forage of similar quality as orchardgrass for their enterprise.

Water Deficit, Heat Tolerance, and Persistence of Summer‐Dormant Grasses in the U.S. Southern Plains

ABSTRACTSummer‐dormant cool‐season grasses are being used in the Southern Plains of the United States in place of traditional summer‐active cultivars for high‐quality winter forage. One reason for this is the ability of cultivars with summer dormancy traits to tolerate increasing annual temperature, decreasing precipitation, and repeated severe summer droughts. Research on adaptation of these grasses and mechanisms of summer dormancy has been conducted at Vernon, TX, since 2000. The experimental location is in a semiarid, subtropical climate with bimodal rainfall pattern with peaks in May and September, and prolonged summer drought. Adaptation and persistence studies involved summer‐dormant and summer‐active cultivars of tall fescue [Lolium arundinaceum (Schreb.) Darbysh.], orchardgrass (Dactylis glomerata L.), perennial ryegrass (Lolium perenne L.), and hardinggrass (Phalaris aquatica L.). Summer‐active types of these grasses were not adapted to this environment and could not survive the first summer after planting. Summer‐dormant types were fully adapted and persisted for at least 5 to 8 yr, depending on species. The most adapted were tall fescue, hardinggrass, and to some extent orchardgrass [subsp. hispanica (Roth) Nyman]. Detailed studies have also been conducted by the Samuel Roberts Noble Foundation at Ardmore, OK. Both research centers have breeding programs for summer‐dormant grasses.

Breeding and Use of Summer‐Dormant Grasses in Southern Australia, with Special Reference to Phalaris

ABSTRACTThe adaptation of introduced perennial grasses in southern Australia expanded with the discovery of the Mediterranean grass phalaris (Phalaris aquatica L.) as a valuable pasture species, and the introduction of Mediterranean ecotypes of orchardgrass (Dactylis glomerata L.), and tall fescue [Lolium arundinaceum (Schreb.) Darbysh.] displaying summer dormancy. In contrast, native grasses of agricultural importance appear to have little or no endogenous summer dormancy. A brief history of cultivar development from Mediterranean germplasm is presented. Recent developments include cultivars based on summer‐dormant subsp. hispanica orchardgrass and the release of Mediterranean‐type cultivars of tall fescue. Phalaris depends on a deep root system and summer dormancy for its summer survival. Cultivars based on more summer‐dormant Moroccan ecotypes have been developed for drier environments. Work to improve phalaris for hotter, summer‐dominant rainfall areas is being extended to enhance the range of perennials for the cropping zone. In addition to ecotype evaluation, breeders should employ recurrent selection in cultivars and populations such as those developed recently for low‐ to medium‐rainfall areas in orchardgrass and tall fescue.

Variation within Poa Germplasm for Salinity Tolerance

As competition for water resources in areas of western North America intensify as a result of increasing human populations, the sustainability of turfgrass irrigation with limited water resources is questionable. A potential part of the solution is the use of recycled wastewater for landscape irrigation. However, as a result of high levels of salt, successful irrigation with recycled wastewater will likely need to be coupled with selection for increased salinity tolerance in turfgrass species. Additionally, salinity-tolerant turfgrass will allow production on soils with inherently high salt levels. The study described here characterized the relative salinity tolerance of 93 accessions of Poa germplasm from the USDA National Plant Germplasm System (NPGS). Control cultivars of tall fescue [Lolium arundinaceum (Schreb.) S.J. Darbyshire], perennial ryegrass (Lolium perenne L.), and kentucky bluegrass (Poa pratensis L.) were also evaluated for comparison. Kentucky bluegrass accessions exhibited a wide range of LD50 (salinity dosage necessary to kill 50% of plants) values from 811 ECdays (PI 369296 from Russia) to 1922 ECdays (PI 371768 from the United States). Five kentucky bluegrass accessions exhibited salinity tolerance equal to or better than that of the tall fescue (LD50 = 1815 ECdays) and perennial ryegrass (LD50 = 1754 ECdays) checks. Thus, there is sufficient variation within this species to develop bluegrass with substantially higher salinity tolerance.

Evaluation of Tall Fescues for Stocker Cattle in the Gulf Coastal Plain

ABSTRACT New cultivars of nontoxic endophyte-infected (NE) tall fescue must be evaluated under grazing conditions before their commercial release. This research was conducted to compare 2 NE tall fescue cultivars with toxic endophyte-infected Kentucky-31 (KY-31) and an endophyte-free (EF) tall fescue in the Coastal Plain region of southwestern Arkansas. Eleven 0.81-ha pastures were planted to KY-31 (n = 3), EF (cv. Barcel, Barenbrug USA, Tangent, OR; n = 3), or the NE tall fescue cultivars BarOptima, infected with the E-34 endophyte (BarOptima PLUS E-34, Barenbrug USA; n = 3), and Jesup, infected with the AR542 endophyte (MaxQ, Pennington Seed Inc., Madison, GA; n = 2). Pastures were grazed by growing beef calves (n = 33/yr, initial BW = 244 ± 9.5 kg) for 2 yr beginning in January of each year. After 2 grazing seasons, pastures that contained endophyte (KY-31, Jesup AR542, BarOptima PLUS E-34) had greater stand counts than EF (P

Variation in Endophyte–Plant Associations Influence Black Cutworm (Lepidoptera: Noctuidae) Performance and Susceptibility to the Parasitic NematodeSteinernema carpocapsae

This study examined how variability in Neotyphodium endophyte-grass associations influences black cutworm Agrotis ipsilon Hufnagel performance and susceptibility to the entomopathogenic nematode Steinernema carpocapsae (Weiser). Second-instar cutworm larvae were confined to greenhouse pots containing four different tall fescue Schedonorus phoenix (Scop.) Holub cultivars. After 1 wk, larvae were recovered from the pots, weighed, and individually exposed to 20 infective juvenile nematodes. Nematode-induced mortality was monitored for 72 h after exposure. Endophyte infection levels and ergot alkaloid concentrations varied between tall fescue cultivars, but endophyte infection level was not a significant predictor of ergot alkaloid concentrations in above-ground plant tissue. Larval survival also varied between cultivars, but neither endophyte infection level nor ergot alkaloid concentration was a significant covariate. Larval susceptibility to the entomopathogenic nematode varied between cultivars at 48 and 72 h after exposure. In all but one cultivar (Plantation), cumulative mortality at 72 h decreased significantly as ergot alkaloid concentrations increased. Neither larval biomass nor endophyte infection levels in tall fescue were significant predictors of larval susceptibility to the nematode. Results show that variation in endophyte-plant associations can influence black cutworm performance and susceptibility to entomopathogenic nematodes and that susceptibility to the nematode H. bacteriophora may be partially tied to ergot alkaloid levels in the insects' food. Findings further support the assertion that black cutworm may use certain endophyte-mediated toxins, particularly ergot alkaloids, as a form of acquired chemical defense against nematode-induced septicaemia.

Endophyte Survival during Seed Storage: Endophyte–Host Interactions and Heritability

Use of nontoxic endophytes in forage tall fescue [Schedonorus phoenix (Scop.) Holub.] is a preferred strategy to overcome fescue toxicosis. Endophytes are transmitted through the seed, but suffer mortality preferentially to the embryo during storage. Loss of viable endophyte reduces the value of the seed, so increasing storage life would be a benefit. The objectives of this study were to examine (i) viability of an endophyte AR542 in different tall fescue cultivars and endophytes AR542 and AR584 in a Jesup tall fescue seed when stored for extended periods of time, and (ii) heritability of endophyte persistence during seed storage. Seed from each population were stored at room temperatures for 18 mo. Jesup plants containing endophyte after 18 mo of seed storage were placed into polycross blocks. Seed from the selected and parent populations, Jesup with toxic endophyte, and Grasslands Flecha with AR542, were stored at 30°C for 22 mo and tested for endophyte monthly. Pairwise t tests and regression analysis were performed to describe the population responses to storage conditions. Heritability of endophyte viability during storage was calculated. Endophyte AR542 viability during storage was greatest in Flecha followed by Jesup and least in Advance, a third tall fescue cultivar studied in addition to Jesup and Flecha. Endophyte AR584 had greater viability during storage than did AR542 when in Jesup. Selection for endophyte survival increased endophyte viability in stored seed and had heritabilities of 38 and 63% for AR542 and AR584, respectively.

Growth, lipid peroxidation and photosynthesis in two tall fescue cultivars differing in heat tolerance

Seedlings (70-d-old) of two tall fescue (Festuca arundinacea Schreb.) genotypes, heat-tolerant Jaguar 3 and heat-sensitive TF 66, were exposed to a high temperature stress of 35/30 °C (day/night) for 20 d and both light-saturated and CO2-saturated leaf stomatal conductance decreased, especially in TF 66. Higher reductions of quantum efficiency, carboxylation efficiency and maximum photochemical efficiency of photosystem 2 in dark adapted leaves (measured as Fv/Fm) occurred in TF 66 than in Jaguar 3. High temperature stress increased photorespiration in the two plants, but more in TF 66. Moreover, high temperature stress also reduced the growth, chlorophyll content and caused cell membrane injuries in the two cultivars, the changes were again more pronounced in TF 66 than in Jaguar 3.

Water-use patterns of tall fescue and hybrid bluegrass cultivars subjected to ET-based irrigation scheduling

In turf industry, the ability of a cultivar to use less water is an important consideration, especially where rainfall and irrigation water are insufficient. Knowledge of turf grass water-use patterns is therefore important for developing efficient water management practices and also for selection of drought-resistant cultivars. We evaluated the soil water‐use patterns of tall fescue and hybrid bluegrasses cultivars irrigated at different rates. Field experiments were conducted at the Turfgrass Research Facility, Auburn University, AL, in 2005 and 2006. Two tall fescue (Festuca arundinacea Schreb.) cultivars (‘Kentucky 31’ and ‘Green Keeper’) and four hybrid bluegrass (Poa pratensis L. × Poa arachnifera Torr.) cultivars, viz., HB 129 [‘Thermal Blue’], HB 130 (Experimental line), HB 328 (Experimental line) and HB 329 [‘Dura Blue’] were included in this study. Plots were irrigated based on the potential evapotranspiration, viz., 100% ET, 80% ET and 60% ET replacements. Tensiometers were installed at 0.075, 0.15 and 0.30 m depths, and their readings used to calculate the matric head, water content and water-use values. Turf color quality was determined from turf canopy digital images. Analysis of variance (ANOVA) for a random complete block design (RCBD) was conducted for available water, water-use and turf color quality values. Hybrid bluegrasses revealed significantly (P = 0.05) higher turf color indices compared to the tall fescue cultivars, but there was no indication of differential responses to irrigation among cultivars. Based on water-use data, hybrid bluegrass cultivars revealed significantly (P = 0.05) lower water-use compared to tall fescue cultivars.

Establishment and persistence of perennial grass and herb cultivars and lines in a recharge area, North-West Slopes, New South Wales

Two adjacent sites, one previously cropped and the other a native pasture, were sown with perennial temperate and tropical grasses and herbs (Expt 1), Phalaris aquatica (phalaris) and Festuca arundinacea (tall fescue) cultivars or lines (Expt 2), and perennial tropical grasses (Expt 3) near Manilla, NSW. Establishment, herbage mass and plant frequency were assessed in 2003–06 to (i) identify cultivars/lines with superior persistence, (ii) detect possible mechanisms required for successful production and persistence in a summer-dominant rainfall environment, and (iii) examine the comparative performance of the species groups when sown into previously cropped and native pasture areas. Plots were fertilised annually and grazed or mown at least seasonally. Most cultivars/lines persisted at the previously cropped site, while those on the native pasture site had to be resown and generally failed to persist beyond the first year. At the previously cropped site, summer-dormant tall fescue cv. Resolute MaxP® was the most persistent of the grasses evaluated in Expt 1. Grasses such as Lolium perenne cv. Avalon and Bromus stamineus cv. Gala did not perenneate, but regenerated annually from seed. Native grasses generally had poor establishment; however, Austrodanthonia richardsonii and A. fulva tended to increase in plant frequency over time. Chloris gayana (Rhodes grass) cv. Katambora and Panicum maximum (panic) cv. Gatton were the only tropical grasses that established in Expt 1, and both had plant frequencies similar (P > 0.05) to the temperate grasses at the final assessment. In Expt 2, Resolute MaxP again was the most persistent cultivar/line. Several experimental lines of phalaris (e.g. T39 and M225) had high herbage mass and good persistence compared with commercial cultivars. In Expt 3, Katambora Rhodes grass and Digitaria eriantha ssp. eriantha (digit grass) cv. Premier were the most persistent cultivars and had the highest herbage mass. These data highlighted summer dormancy in temperate grasses and frost tolerance in tropical grasses as two possible mechanisms important for persistence of grasses on the North-West Slopes of NSW and the risks associated with sowing perennial grasses into established native pastures.

Fungal Endophyte Removal Does Not Reduce Cold Tolerance of Tall Fescue

Tall fescue [Schenodorus phoenix (Scop.) Holub.] has historically been of minor importance to livestock agriculture in cooler regions of the temperate zone. As its use in these regions expands, it becomes increasingly important to understand the effect of infection by its fungal endophyte (Neotyphodium coenophialum Morgan‐Jones and Gams) on agronomic fitness of tall fescue. Our objective was to determine the effect of endophyte infection status on forage yield and survival of tall fescue under field conditions in which freezing temperatures, combined with lack of persistent snow cover, constitute the most significant stress factor. In Experiment 1, we evaluated 427 half‐sib families of four tall fescue cultivars, half endophyte‐infected (E+) and half endophyte‐free (E−), for forage yield and survival. There was no effect of endophyte removal on either forage yield or survival, despite complete stand loss of one cultivar during two winters. In Experiment 2, we evaluated 640 clones of confirmed endophyte status, half E+ and half E−, for survival under two management regimes at four Wisconsin locations. Results were nearly identical to those for Experiment 1, with complete mortality in the unadapted cultivar and high survival rates in the three adapted cultivars, regardless of endophyte status, management, or location. In conclusion, we found no evidence that endophyte removal resulted in any disadvantage to tall fescue host‐plant survival under harsh winter conditions. In regions where freezing temperatures and desiccating winds provide the only or most important abiotic stress factor, removal of endophytic fungi do not appear to reduce fitness of their tall fescue host.

Morpho-physiological Responses of Several Fescue Grasses to Drought Stress

Identification and screening of grasses with excellent drought tolerance is a desirable strategy in breeding drought-tolerant turf and forage cultivars. Not all fescue selections and cultivars may be equally drought tolerant. An Atlas fescue (Festuca mairei St. Yves) selection and three tall fescue (Festuca arundinacea Schreb.) cultivars—Barolex, Kentucky 31, and Falcon II—were subjected to increasing drought stress for a 12-week period. Soil water content (SWC), leaf elongation (LE), leaf water content (LWC), and leaf water potential (Ψw) were measured weekly, and root length (RL) and biomass (RM) were recorded after 12 weeks. The SWC declined progressively during the 12-week drought treatment for all grasses. However, for the three tall fescue cultivars, the SWC decreased at a faster rate than for Atlas fescue. This indicated that Atlas fescue extracted soil water more slowly and developed less-intensive stress than the three tall fescue cultivars. The LE, LWC, and leaf Ψw decreased in drought-treated plants of all grasses; nevertheless, the values for the Atlas fescue remained similar to control plants for a longer period of time than the values for the three tall fescue cultivars. Drought stress significantly reduced root biomass and root length of the grasses. These four Festucas avoid drought stress through changes in leaf and root morphology and probably through osmotic adjustment to maintain sufficient turgor pressure in the growing zone for leaf elongation. The slower decrease in LE, LWC, and leaf Ψw for Atlas fescue during the drought-stress period suggested greater drought tolerance and the potential value for improving this character in a breeding program.

Effects of foliar application of nitrogen on the photosynthetic performance and growth of two fescue cultivars under heat stress

The effects of nitrogen fertilization on the growth, photosynthetic pigment contents, gas exchange, and chlorophyll (Chl) fluorescence parameters in two tall fescue cultivars (Festuca arundinacea cv. Barlexas and Crossfire II) were investigated under heat stress at 38/30 °C (day/night) for two weeks. Shoot growth rate of two tall fescue cultivars declined significantly under heat stress, and N supply can improved the growth rates, especially for the Barlexas. Chl content, leaf net photosynthetic rate, stomatal conductance, water use efficiency, and the maximal efficiency of photosystem 2 photochemistry (Fv/Fm) also decreased less under heat stress by N supply, especially in Crossfire II. Moreover, cultivar variations in photosynthetic performance were associated with their different response to heat stress and nitrogen fertilization, which were evidenced by shoot growth rate and photosynthetic pigment contents.

Does endophyte influence resource acquisition and allocation in defoliated tall fescue as a function of microsite conditions?

Tall fescue [ Lolium arundinaceum (Schreb.) Darbysh.] often benefits in terms of productivity and persistence when infected with Neotyphodium coenophialum ([Morgan-Jones and Gams], Glenn, Bacon, and Hanlin) endophyte, but the influence of novel non-ergogenic endophytes is unclear. We conducted a field experiment using container-grown tall fescue plants to determine how plants allocated resources when clipped repeatedly in microsites differing in the amount of available light associated with open (full sun), and partially shaded (about 20 or 40% of full sun) conditions. Plants of the same tall fescue cultivar (Jesup) were host to either a native or novel non-ergogenic fungal endophyte (MaxQ™), or were devoid of endophyte. Seedlings of plants infected with the novel endophyte had slower germination, germinated later, and allocated more photosynthate to shoots than roots, when compared to J− or J+ plants. Herbage production of undisturbed canopies was not influenced by host–endophyte association within a microsite, with more herbage produced at the open than at the heavily shaded site. Clipping plants to a 5- or a 10-cm residue height tended to accentuate differences, with diminished productivity and greater variability occurring when plants were maintained at 5 cm. This trend was supported by allometric resource allocation patterns, and in terms of vegetative propagule mass relative to the number of propagules. Tall fescue, irrespective of host–endophyte association, grown as forage in silvopastoral situations should be managed to maintain no less than a 10-cm residual plant height. Trends in photosynthate allocation and plant size might influence persistence and should be investigated for more than two growing seasons.

Field evaluation of phalaris, tall fescue and cocksfoot cultivars and accessions in western Victoria, Australia

To assess their potential usefulness in the central and south-western Victorian environment, cultivars/experimental varieties and accessions of each of three perennial grasses, phalaris (Phalaris aquatica L.), tall fescue (Festuca arundinacea Schreb. = syn. Lolium arundinaceum. (Schreb.) Darbysh.), and cocksfoot (Dactylis glomerata L.), were established as swards by spring-sowing and then evaluated under rotational grazing by sheep. Pasture establishment, production, and survival following severe drought were measured at two locations. Persistent novel material of phalaris and tall fescue was identified that could increase the cool-season and year-round production relative to that obtained from current commercial cultivars. Phalaris and tall fescue varieties were compared at Hamilton. Results indicated that, in contrast to tall fescue, the seedling vigour of winter-active phalaris types was similar in spring relative to that of summer-active types. Most phalaris cultivars were more productive than tall fescue in autumn and winter (P < 0.05). For the experimental phalaris variety Perla × Sirocco, dry matter (DM) production during these seasons was 19% greater than for the most productive tall fescue, cv. Fraydo (P < 0.05). In a short growing season site at Warrak, winter-active cultivars of tall fescue produced up to 17% more DM in winter (P < 0.05) than the highest yielding, summer-active cv. Quantum MaxP, but for cumulative production over 3 years, Quantum MaxP was significantly more productive (P < 0.05) than 18 other entries. However, the persistence of Quantum and Quantum MaxP declined considerably post-drought; a more persistent accession from Sardinia, FA 005, was as productive as Quantum MaxP. Of the 13 cultivars compared in the longer growing season of Hamilton, Fraydo and Resolute MaxP were the most productive in winter (P < 0.05). For cumulative herbage yield over 4 years, Fraydo, Quantum MaxP, Quantum, Resolute MaxP, and Tanit were the most productive cultivars (P < 0.05). Infection with the MaxP endophyte did not affect persistence of Quantum at either site but improved the persistence of Resolute at Hamilton (P < 0.05). At Warrak, MaxP endophyte-infected Quantum was 35% more productive in summer–autumn than the endophyte-free cv. Quantum (P < 0.05). Compared with the most productive commercial cv. Holdfast, experimental varieties from breeding populations of winter-active phalaris selected for grazing tolerance and which incorporated Perla, were superior for seedling vigour (rating 5 v. 3), winter growth (by ≥15%), and cumulative production over 4 years (≥12%) (P < 0.05).

Persistence of winter-active phalaris breeding populations, cultivars and other temperate grasses in diverse environments of south-eastern Australia

Three winter-active populations of phalaris (Phalaris aquatica L.), selected over two generations for improved persistence under grazing, were evaluated with commercial cultivars of phalaris and other temperate perennial grasses from 1999–2003 in three environments of south-eastern Australia as part of a program to develop a cultivar for more sustainable pastures and to assess genotype × environment interaction. Grazed sites were located at Bulart in western Victoria, and Rye Park on the Southern Tablelands and Tamworth on the North West Slopes of New South Wales. At the conclusion of the experiment, the frequency of live plant base was highest at Rye Park despite soil acidity and drought. Significant variance among half-sib families in each population was also observed most frequently at this site. Frequency was intermediate at Bulart but lower than expected considering high soil fertility, probably because of high grazing pressure. Frequency was lowest at Tamworth where severe drought occurred from 2001 onwards. There was significant genotype × environment interaction for frequency among half-sib families. Significant common family variance for frequency across the Bulart and Rye Park sites was demonstrated, but not between Tamworth and either of the other sites in later years. The relationship between winter herbage mass potential and persistence differed with population and site, and was negative for one population at Bulart but positive for another population at Tamworth. Mean persistence of all families was 30% higher than winter-active controls at Rye Park and at least 40% higher at Bulart. Phalaris generally persisted better than cultivars of tall fescue (Festuca arundinacea Schreb.), cocksfoot (Dactylis glomerata L.) and perennial ryegrass (Lolium perenne L.) with some exceptions, particularly at Bulart. Development of a winter-active phalaris cultivar with improved persistence under grazing was considered possible for the Southern Tablelands and western Victorian environments with these populations but a separate program using additional germplasm will be needed for the North West Slopes environment.

Effect of traffic stress on cool-season turfgrass under a Mediterranean climate

Cool-season turfgrass for sporting use is an agronomic cultivation whose green surface is used for professional activities. On ecological grounds, turfgrass in towns is a system that can reduce atmospheric pollution, e.g. by CO2 sequestration. Here, I studied the impact of traffic on turf quality traits of turfgrass. The experiment, established in Southern Italy in the years 1999 to 2004, evaluated the impact of 2 levels of traffic stress on 3 types of turfgrass binary blends made by cultivars of tall fescue, Kentucky bluegrass, perennial ryegrass and bermudagrass species. Grasses were grown on 4 different substrates established by a mix of soil sand at 2 fertilization levels of 100 and 200 N units kg h−1 yr−1. I evaluated the effect of the impact on three turfgrass qualitative traits, visually assessed using rating scores from 1 to 9. The lowest score values of turf quality, color and cover traits were, respectively, 5.6, 5.7 and 5.8 recorded for blend Kentucky bluegrass and perennial ryegrass under United States Golf Association sandy soil substrate, using 200 N fertilizer units and a high level of traffic stress. The highest score was 7.1 for turf quality and color and 8.0 for cover traits assessed for autochthonous soil substrate under 200 N fertilizer units and the second level of traffic stress. Furthermore, the 200 N units increased all the qualitative characteristics of turf lawn. The turfgrass growing on 65–70% sand substrate with 100 N units fertilizer and a high level of traffic stress was an ecological green structure able to sustain the physiological process for reducing pollution in the atmosphere.

Yield, persistence, and nutritive value of autumn harvested tall fescue

Tall fescue, harvested or grazed in autumn, may be a potential source of forage but little is known of the effect of a fall harvest or grazing on yield and nutritive value of tall fescue in the mid-north of eastern Canada (˜ 1400 growing degree-days). Three tall fescue cultivars (Courtenay, Kokanee, and Montebello) were submitted to 10 harvest management treatments (two dates of second harvest and five dates of third harvest) over 3 production years in the Saguenay-Lac-St-Jean region (QC). The cultivars Courtenay and Kokanee were more productive and persistent than Montebello. The annual DM yield decreased by an average of 15% between the first and the second production year and by an average of 35% between the first and the third production year; these decreases were greater (22 and 41%, respectively) when the third harvest was taken in early October. Increasing from 28 to 35 d the interval between the first and second harvests increased DM yield of the second harvest by more than 0.5 Mg ha-1, but caused a greater reduction in DM yield of the third harvest, primarily during the first 2 production years. Third-harvest DM yields of more than 4.0 Mg ha-1 were obtained in the first and second production years, while third-harvest DM yields varied from 2.5 to 3.0 Mg ha-1 in the third production year. With the delay of the third harvest in autumn, the concentration of crude protein decreased to 120 g kg-1 DM, the concentration of water-soluble carbohydrates increased to 150 g kg-1 DM, while that of acid detergent fibre changed very little. Tall fescue has a significant yield potential in late summer and early autumn in the mid-north of eastern Canada, primarily in the first 2 production years. However, harvesting or grazing tall fescue in the week preceding or following the first killing frost will reduce persistence and spring regrowth the following year. Key words: Lolium arundinaceum (Schreb.) S. J. Darbyshire, cutting management, cultivars, water-soluble carbohydrates

Seasonal animal production of temperate and Mediterranean tall fescue cultivars under continuous variable stocking with close control of sward state

In temperate regions, tall fescue (Festuca arundinacea Schreb.) cultivars derived from Mediterranean germplasm out-perform cultivars of temperate origin during autumn and winter, but the opposite occurs in spring and summer. This study assessed whether such seasonal differences are expressed under grazing and can thus be translated into animal production. Swards of ‘El Palenque’, a temperate cultivar, and of ‘Maris Kasba’, a cultivar developed from Mediterranean germplasm, were grazed under continuous stocking with frequent adjustment of the stocking rate to maintain similar sward state, in temperate Argentina. Liveweight gain per animal (LWGA) and per unit area was determined over 4 consecutive 1-year-long fattening cycles of Angus steers. Close control of sward state resulted in swards of similar height (82 ± 2.5 v. 83 ± 4.5 mm for El Palenque and Maris Kasba, respectively) and herbage mass (96 ± 13 v. 108 ± 8 g DM/m2). Thus, animals grazed structurally very similar swards in both cultivars, throughout the trial. Both cultivars showed similar seasonal trends in LWGA, but markedly contrasting seasonal patterns of carrying capacity. During autumn–winter, LWGA was 507 g/animal.day, but the temperate and Mediterranean cultivar supported, on average, 1.9 and 2.9 animals/ha, respectively. In spring, LWGA was 843 g/animal.day, but the temperate and Mediterranean cultivar supported, on average, 4.3 and 2.9 animals/ha, respectively. Thus, the established cultivar × season interaction in primary productivity was confirmed in terms of animal production. Mediterranean germplasm is certainly an option for increasing the carrying capacity of temperate-humid systems based on direct grazing during the critical period of low temperatures, helping to smooth annual forage supply.

First-year Response of Turf-type Tall Fescue Cultivars to Different Fertilization Rates and Mowing Heights in Semiarid Conditions

Tall fescue (Festuca arundinacea) has desirable attributes as a cool-season turfgrass for the semiarid southwestern United States and the transition zone, but effects of cultural practices on newer cultivars within a desert climate are not adequately known. A field study was conducted between Sept. 1996 and Nov. 1997 to evaluate establishment of 15 turf-type tall fescue cultivars under two mowing heights (2 or 3 inches) and two different annual nitrogen (N), phosphorus (P), and potassium (K) application rates (N at 13.2 or 26.4 g·m−2, P at 0.9 or 1.8 g·m−2, and K at 11.0 or 22.0 g·m−2). The cultivars included ‘Amigo’, ‘Apache’, ‘Aztec’, ‘Bonanza’, ‘Chieftain’, ‘Cochise’, ‘Confederate’, ‘Coronado’, ‘Crossfire II’, ‘Falcon’, ‘Guardian’, ‘Kentucky 31’, ‘Leprechaun’, ‘Shortstop’, and ‘Virtue’. The fertilizer rate had no effect on turfgrass quality ratings throughout the establishment period, although overall quality was higher in Fall 1997 than during Spring and Summer 1997. The mowing height of 2 inches increased summer quality ratings of 11 of the 15 cultivars as compared with ratings under the 3-inch mowing height. The 2-inch mowing height improved fall quality ratings of seven of the 15 cultivars. No cultivars responded positively to the 3-inch mowing height. Consistently high summer through fall quality ratings were observed when ‘Apache’, ‘Aztec’, and ‘Crossfire II’ were mowed at the 2-inch height as compared with the other cultivar × mowing height treatment combinations. For turf-type tall fescue establishment in semiarid climates, findings support use of a 2-inch mowing height combined with the selective planting of ‘Apache’, ‘Aztec’, and ‘Crossfire II’ over other cultivar × mowing height combinations tested in the study.