EVAPOTRANSPIRATION AND PERFORMANCE AMONG TURFGRASS AND ORNAMENTAL LANDSCAPE SPECIES IN RESPONSE TO IRRIGATION DEFICIT

摘要

Water conservation is an increasingly important issue in the lawn and landscape industry.Turfgrasses have been singled out for replacement with presumably more water efficient plant species to conserve water despite limited research on comparative water use between popular turfgrasses and other landscape species.We evaluated water use and performance of two turfgrass and two ornamental species under irrigation deficits.Evapotranspiration (ET) was measured using lysimeters and plant water status was evaluated under deficit irrigation (100%,60%,and 20% ET) in Festuca arundinacea Schreb.,Buchloe dactyloides (Nutt.) Engelm.‘Sharps Improved’,Ajuga reptans L.‘Bronze Beauty’,and Vinca minor L.These studies were conducted during the summers of 2010 and 2011 under a rainout shelter near Manhattan,KS,USA.Only the first four weeks of data were evaluated for V.minor in both years due to a severe fungus infestation (Phoma exigua).During those four weeks,ET generally ranked: A.reptans (4.5/5.6 mm d-1) = F.arundinacea (4.5/5.3 mm d-1) > V.minor (3.6/4.4 mm d-1) ≥ B.dactyloides (2.9/3.4 mm d-1) (2010/2011).The average ET of the three species evaluated over the entire study ranked: A.reptans (4.0/5.0 mm d-1) = F.arundinacea (4.4/5.0 mm d-1) > B.dactyloides (2.7/3.4 mm d- 1) (2010/2011).Results indicate B.dactyloides is a good choice for landscapes where water is limited because it maintained acceptable visual quality with less water.A.reptans and F.arundinacea may be less appealing choices given their high ET rates and lower visual quality under deficit irrigation.