Comparative Turfgrass Evapotranspiration Rates and Associated Plant Morphological Characteristics

Abstract

Since water costs are projected to increase substantially, and water availability for turfgrass culture will become more limiting, there is a need for a detailed characterization of water use rates among turfgrass species. The evapotranspiration (ET) rates of 11 C‐4 warm‐season turfgrasses and one C‐3 cool‐season turfgrass were evaluated in minilysimeters with fritted clay as the rooting medium utilizing the water balance method. Turf plots of 1.5 × 1.5 m were constructed to ensure a natural environment surrounding each lysimeter. Evapotranspiration rates plus six morphological characteristics of each species were measured under nonlimiting soil moisture. Significant differences in ET rates were observed both among and within genera. ‘Texas Common’ buffalograss [Buchloe dactyloides (Nutt.) Engelm], ‘Georgia Common’ centipedegrass [Eremochloa ophiuroides (Munro.) Hack], ‘Arizona Common’ bermudagrass [Cynodon dactylon (L.) Pers.], ‘Tifgreen’ and ‘Tifway’ bermudagrasses [C. dactylon (L.) Pers. × C. transvaalensis Davy], and ‘Adalayd’ seashore paspalum (Paspalum vaginatum Sw.) had low ET rates; while ‘Emerald’ zoysiagrass (Zoysia japonica Steud. × Z. tenuifolia Willd. ex Trin.) was characterized as having a medium ET rate. ‘Texas Common’ St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] and ‘Meyer’ zoysiagrass (Z. japonica Steud.) possessed medium low ET rates. However, a 1‐yr study showed that ‘Kentucky 31’ tall fescue (Festuca arundinacea Schreb.) and ‘Argentine’ bahiagrass (Paspalum notatum Flugg.) had medium ET rates, and ‘Common’ blue grama [Bouteloua gracilis (H.B.K.) Lag. ex Steud.] possessed a medium low ET rate. Those grasses with comparatively lower ET rates were generally characterized by (i) a high canopy resistance, including a high shoot density and relatively horizontal leaf orientation; and (ii) a low leaf area, including a slow vertical leaf extension rate and a narrow leaf texture.