QUALITY AND GROWTH-RESPONSE OF CENTIPEDEGRASS TO EXTENDED DROUGHT

Many of today's landscapes require turfgrasses that can survive extended drought periods without supplemental water. Centipedegrass [Eremochloa ophiuroides (Munro.) Hack.] has long been used as a low-maintenance lawn grass for the Southeast. A controlled drought study was used to determine the quality, growth, and recovery of centipedegrass held in stress for periods of 7 to 30 d. Common centipedegrass, established under an automated rainfall shelter, was subjected to three drought (drydown) regimes - NOSTRESS, watered twice per week; MODERATE, 2 to 3 wk between watering; and SEVERE, 4 to 6 wk between watering. Soil water was monitored daily to 0.7 m depth with resistance type sensors. Clipping biomass, relative leaf water content, and visual rating were monitored weekly. Available water dropped below 30% in the 0.7 m profile in 7 to 14 d after complete rewetting, and drought stress, indicated by wilting, became evident. The period of drought stress extended for 10 to 30 d during which weekly clipping biomass decreased by 50 to 70% below that of NOSTRESS turf. Visual ratings declined along with biomass decrease, falling below acceptable quality rating when drought stress lasted longer than 7 to 10 d. Relative leaf water content declined from about 80% for NOSTRESS to as low as 40% at the end of the SEVERE drought periods. Recovery of leaf water content following watering was not complete, due either to an adaptive response to drydown or to incomplete recovery of the grass. When as much as 3 wk elapsed between watering, irription of centipedegrass resulted in recovery of clipping biomass and visual ratings nearly to that of the NOSTRESS treatment. When drought extended for 6 wk, turf quality was low, but centipedegrass survived and recovered to levels suitable for lawns.