Response and Recovery Characteristics of Kentucky Bluegrass Cultivars to Extended Drought

During drought, authorities may impose water restrictions for irrigation with little regard for damage to turfgrass. Our objectives were to evaluate the performance of Kentucky bluegrass (Poa pratensis L.) (KBG) cultivars during a prolonged dry down and subsequent recovery in the transition zone near Manhattan, KS, USA. Irrigation was withheld from 30 bluegrasses for 82 days in 2010 and 62 days in 2011. Rainfall was excluded from the study area with an automated rainout shelter. Digital images were collected every one to two weeks during dry down and recovery to obtain percent green turfgrass coverage. All cultivars were predominantly brown (0 to 3% green cover) by the end of the 82-day dry down in 2010, and less brown (7 to 27% green cover) by the end of the 62-day dry down in 2011, probably because all plots inadvertently received 1.54 inches of precipitation during the 2011 dry down. All 30 bluegrasses recovered after lengthy dry downs in both years, but recovery was slower in 2010 because of greater drought stress during the longer dry down. Differences in performance were observed among cultivars during the dry downs and recoveries, but were inconsistent between years. Exceptions during the dry down were Apollo and Bedazzled, which lost green cover more slowly than other cultivars; Apollo also recovered more quickly after drought than other cultivars. Bluegrasses have excellent recuperative ability even after severe drought, and are good choices for areas where extended bans on turfgrass irrigation are possible.