Drought‐Resistance Mechanisms of Seven Warm‐Season Turfgrasses under Surface Soil Drying: II. Root Aspects

Abstract

Knowledge of drought‐resistance mechanisms in turfgrasses would improve management strategies and facilitate turfgrass breeding for drought resistance. The experiment investigated root morphological and physiological characteristics in response to surface soil drying and rewatering for bermudagrass [Cynodon dactylon (L.) Pers. ‘Common’], centipedegrass [Eremochloa ophiuroides (Munro) Hack ‘Tif‐Blair’], seashore paspalum (Paspalum vaginatum Swartz, four ecotypes), and zoysiagrass (Zoysia japonica Steudel × Z. tenuifolia Steudel ‘Emerald’). Plants were grown in sectioned PVC tubes with four soil moisture regimes in a greenhouse during 1995 and 1996. Root growth was reduced when the upper 20‐ and 40‐cm soil layers dried for Emerald zoysiagrass, Common bermudagrass, and Adalayd paspalum, but only with upper 40‐cm soil drying for PI 299042, AP14, and PI 509018 paspalums, and TifBlair centipedegrass. Root dry weight recovered fully to control levels after rewatering for TifBlair centipedegrass and the three paspalum accession, but only partially for Adalayd paspalum, Common bermudagrass, and Emerald zoysiagrass. Superior drought resistance to surface soil drying for PI 509018 paspalum and TifBlair centipedegrass was associated with enhanced root growth and rapid root water uptake at deeper soil layers, maintenance of root viability at the surface drying soil, and rapid root regeneration after rewatering. Differences in these drought avoidance characteristics among turfgrasses could serve as selection criteria for improving turf drought resistance.

Effects of varied water regimes on root length, dry matter partitioning and endogenous plant growth regulators in sunflower (Helianthus annuusL.)

“…AMES-10107 and CM-614 showed stability in total root length under drought stress when compared with non-stress regime. Huang et al (1997) found that, although total root length influences water and nutrient uptake, root growth maintenance during drought was more important for plant tolerance to drought.…”

Nitrogen budgets of urban lawns under three different management regimes in southern California

“…In general, plant urease activities and root uptake of N and water can affect the magnitudes of NH 3 volatilization (Frankenberger and Tabatabai 1982), N leaching (Bowman et al 2002;Crush et al 2005), and denitrification (Virginia et al 1982). C 4 , warm-season turf species are known for low water requirements (Huang et al 1997;Youngner et al 1981). In semi-arid urban ecosystems, these species may be associated with reduced water and N inputs and smaller ecosystem N losses relative to C 3 , cool-season species because of higher productivity and high efficiencies in N and water use under warm temperatures (Long 1999).…”

Performance of Three Warm Season Turfgrasses under Linear Gradient Irrigation

“…Despite these discrepancies, the work was still carried out using clay soils because such soils were the primary type of soils in Singapore in which most lawns were constructed and grown from. In addition, it is noteworthy that apart from the soil and climatic environment, the ability for deep rooting is another important component of drought resistance in turfgrasses (Huang et al, 1997;Qian and Engelke, 1999;Zhang et al, 2013;Zhang and Unruh, 2015). Drier conditions tended to stimulate greater allocation towards root rather than shoot biomass (Table 5).…”