Economical, rapid methods are needed to identify drought‐tolerant turfgrasses. Objectives of this study were to (i) examine water relations of three tall rescue (Festuca arundinacea Schreb.) selections, (ii) determine the relationship between these characteristics and recovery from water deficit under greenhouse conditions, and (iii) assess the feasibility of using a competitive soil moisture extraction technique to select tall rescue germplasm with superior drought tolerance. Three tall rescue selections were vegetatively propagated and grown together in 38‐L weighing lysimeters to allow interplant competition for available soil moisture. Adequate irrigation and fertilizer were applied for 12 wk after planting; irrigation was then withheld for 8 wk. Tiller survival among selections ranged from 2 to 37% and plant survival ranged from 22 to 76% at 4 wk after irrigation was resumed. Survival was associated with low basal osmotic potential before stress and osmotic adjustment, prolonged positive turgor maintenance, and delayed leaf rolling during stress. Leaf rolling scores, and tiller and plant survival during competitive soil moisture extraction were easily assessed indicators of tall fescue germplasm drought tolerance.

Tall fescue (Festuca arundinacea Schreb.) is grown as a forage, turfgrass, and conservation grass from the Gulf Coast to Canada in the eastern USA. The presence of endophytes in grasses can confer resistance to insect pests, enhance growth, and improve tall fescue persistence under high temperature and drought stress. Most tall fescue is infected with Acremonium coenophialum Morgan‐Jones & Gams, a fungal endophyte. Our objectives were to determine the effects of endophyte infection on water relations and survival of water stressed (i.e., drought‐stressed) tall rescue under greenhouse conditions. Endophyte‐free and infected plants of three tall fescue selections were vegetatively propagated and grown together in 38‐L weighing lysimeters to allow interplant competition for available soil moisture. Irrigation water and fertilizer were applied for 12 wk after planting before irrigation water was withheld for 8 wk. Water‐relation characteristics including full‐turgor osmotic potential (ψπ100), water potential at zero turgot (ψL0), relative water content at zero turgot (RWC0), apoplastic water fraction (β), bulk modulus tissue elasticity (ϵ), and the turgid weight to dry weight ratio (TW/DW) were determined before and after water stress. Osmotic adjustment (Δψπ) was also determined. Endophytein fection did not affect ψπ100, ψL0, RWC0, and β either before or after water stress and did not affect Δψπ. Endophyte infection did affect ϵ and the TW/DW ratio, but this effect was not sufficient to alter ψL0. Total tillers, tiller survival, plant survival, and recovery weights were similar for endophyte‐free and ‐infected plants. No evidence for endophyte‐mediated drought tolerance was observed in this study. Based on this work, endophyte‐mediated drought resistance may be due to alterations in drought avoidance.

Festuca spp., fine fescue turfgrasses, include several species: Festuca rubra L. rubra, strong creeping red fescue; F. rubra L. litoralis (G.F.W. Meyer) Auquier, slender creeping red fescue; F. rubra L. commutata Gaud., Chewings fescue; F. longifolia Thuill. (F. ovina var. duriuscula L. Koch), hard fescue; F. ovina L., sheep fescue; F. ovina L. glauca Lam. (F. glauca Lam.), blue fescue; and F. tenuifolia Sibth., hair fescue or fine‐leaved sheep fescue. Extensive variability exists within these species. Fine fescues are shade tolerant and drought resistant. Improvements sought for these species include better wear tolerance, insect and disease resistance, and sod‐forming ability. Additional germplasm for breeding may be acquired from areas of European origin and naturalized stands in the USA, such as the eastern seacoast, where initial colonization occurred. A major limitation to germplasm enhancement among species results from differences in anthesis date and time of flowering each day, as well as chromosome number. Taxonomic classification of species is disputed. Certain species, such as Sheep fescue are indigenous to the USA or may have native components, but further collection and study is needed for genomic clarification. Chromosome similarities determined by chromosome counts and flow cytometry of nuclear DNA content may determine feasible crosses leading to taxonomic clarification.

Development of drought resistant, water‐conserving cultivars continues to be an objective of turfgrass breeding programs. This study was conducted to determine for 15 zoysiagrasses [Zoysia japonica Steud., Z. matrella (L.) Merr., and Z. japonica Steud. × Z. tenuifolia Willd.] under greenhouse conditions (i) water relations characteristics, (ii) survival and recovery from extreme water stress, and (iii) the relationship of water relations characteristics to supplemental irrigation requirement determined in field studies. Leaf water potential at zero turgor (ΨL0) ranged from −1.76 MPa to −2.52 MPa before, and from −2.18 MPa to −2.59 MPa after water stress. Though ΨL0 of genotypes such as Cavalier, El Toro, and Emerald decreased after stress, ΨL0 of genotypes such as Korean Common and DALZ8515 did not change. Osmotic potential at full turgor (Ψπ100) of genotypes such as DALZ8501 and DALZ8506 was similar or increased after water stress but decreased for genotypes such as Crowne and Korean Common. The ΨL0 and Ψπ100 after stress were negatively correlated with recovery from stress and positively correlated with irrigation requirement. Zoysia genotypes with low relative water content at zero turgor (RWC0), bulk modulus of tissue elasticity (ε), and apoplastic water fraction (β) demonstrated poor recovery from stress and required more supplemental irrigation. Cultivars such as Crowne, El Toro, and Palisades had the greatest recovery from stress, the least irrigation requirement, more negative ΨL0 and Ψπ100, and positive RWC0, ε, and β. This study demonstrates that improvements in biophysical as well as morphological traits should contribute to development of water‐conserving Zoysiagrass germplasm.