COMPETITIVE TURGOR MAINTENANCE IN TALL FESCUE

Economical, rapid methods are needed to identify drought-tolerant turfgrasses. Objectives of this study were to (i) examine water relations of three tall fescue (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 fescue germplasm with superior drought tolerance. Three tall fescue 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.