Response of Six Bermudagrass Cultivars to Different Irrigation Intervals

Abstract

A 2-year greenhouse study was conducted at Clemson University, Clemson, S.C., in 2003 and 2004 to determine drought responses of six bermudagrass ( Cynodon spp.) cultivars at four irrigation intervals. Cultivars selected from the 2002 National Turfgrass Evaluation Program Bermudagrass Trial were `SWI-1012', `Arizona Common', `Tift No.3', `Tifsport', `Aussie Green', and `Celebration'. Treatments included 5-, 10-, and 15-day irrigation intervals plus a control (irrigated daily). Volumetric soil water content (VSWC) and evapotranspiration (ET) rates were recorded every 3 days. Turfgrass quality (TQ) was observed weekly and root weight was measured at the end of a 6-week study. `Aussie Green' and `Celebration' produced the highest TQ rating (>7) at week 4 when watered daily. After 4 weeks of the 5-day irrigation interval, all cultivars showed unacceptable quality ratings (<7). However, `Aussie Green' and `Celebration' were able to maintain an acceptable TQ rating (7), compared to `Arizona Common' (5.1) and `Tift No.3' (5.8) at week 2 (5-day treatment). `Celebration' produced 114% and 97% greater root weight than `Tifsport' and `Aussie Green', respectively, when pooled across all irrigation treatments. At the 15-day irrigation interval treatment, six bermudagrass cultivars pooled together produced 78%, 22%, and 11% greater root weight vs. control, 5-day, and 10-day treatments, respectively. When pooled for all treatments, `Aussie Green' and `Celebration' VSWC was 5% and 7% lower than `Tift No.3', and ET rates were 26% and 30% greater than `Arizona Common'. Based on these results, irrigating bermudagrass in 5-day intervals should be carefully monitored.