Drought Associated Rooting Characteristics of Warm Season Turfgrass Species.

A greenhouse study was conducted within a controlled environment at the University of Florida during the month of July, 2012. The study was set up in a randomized complete block design (RCBD), with four replications (separately for dry down and well water treatments) of sixteen warm season turfgrass genotypes comprised of commercial cultivars and experimental genotypes available from the UF turfgrass breeding program. Genotypes include:   Celebration, UFCD 347, UFCD 12, and PI 289922 bermudagrass; JaMur, TAES 4360, TAES 529-24, and BA 182 Zoysia japonica; PristineFlora, Zeon, BA 336, and BA 374 Zoysia matrella; and Floratam, Captiva, Palmetto, and Sapphire St. Augustinegrasses. All entries were clonally propagated in a greenhouse and a single 3.8 × 3.8 cm plug were transplanted into each 90 × 3.5 cm tube. Turface calcined clay (Profile Products LLC, Buffalo Grove, IL) was used as the rooting media in the tubes. A chamber was inserted over the tubes and IRGA was used to measure photosynthesis and transpiration. At harvest, tubes were cut into sections of 30 cm length.  Roots within each (0-30, 30-60 and 60-90 cm) sections were then washed, scanned and analyzed using WinRhizo software (RegentTechnology, Canada) to determine root morphological parameters. Specific parameters measured were: root length (cm), average root diameter (mm), average volume (cm³), and root surface area (cm²). Rooting characteristics were studied  to see species difference in response to drought.