Drought Resistance Aspects of Turfgrasses in the Southeast: Root‐Shoot Responses

Abstract

Knowledge of relative drought resistance is important for selecting turfgrasses that persist during drought stress. Seven of the most commonly used turfgrasses in the Piedmont region of the humid Southeastern USA were evaluated in a field study under edaphic stresses common to the region for drought resistance and spatial rooting responses as a component of drought avoidance. Grasses were ‘Tifway’ bermudagrass (Cynodon dactylon × C. transvaalensis); common bermudagrass [C. dactylon (L.) Pers.]; ‘Meyer’ zoysiagrass (Zoysia japonica Steud.); common centipedegrass [Eremochloa ophiuroides (Munro.) Hack.]; ‘Raleigh’ St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze]; and ‘Rebel II’ and ‘Kentucky‐31’ tall fescue (Festuca arundinacea Schreb.). Grasses varied in drought resistance, as determined by wilt and leaf firing during dry‐down periods, from very high (Tifway and common bermuda), high (Raleigh St. Augustine, common centipede), medium‐high (Rebel II tall fescue), medium (K‐31 tall fescue), and medium‐low (Meyer zoysiagrass). High soil strength and acid soil complex stresses were present on the site. Under these stresses, deep rooting (20‐ to 60‐cm zone) in late summer ranged from Tifway bermuda (best) > Rebel II tall fescue = common bermuda > K‐31 tall rescue > Raleigh St. Augustine > common centipedegrass > Meyer zoysiagrass. Meyer produced only 4% of the root length density that Tifway did within this zone due to low genetic tolerance to the edaphic stresses. These results illustrate that genetic tolerance to edaphic stresses can markedly affect turfgrass rooting and drought resistance rankings. Plant breeders must give attention to edaphic stress tolerances if drought avoidance via roots is to be improved.