Sod Tensile Strength and Handling Quality of Entries in the 2013 NTEP Bermudagrass Trial at Stillwater, OK.

Turfgrass sod is a pad of grass with its intermingled shoot and root system as well as adhering soil. To be successfully used as a sod crop, a turfgrass must have a suitable production cycle and sod handling/transport characteristics. Thirty-nine cultivars of Bermudagrass were evaluated for sod handling quality (SHQ) and sod tensile strength (STS). Sod tensile strength (STS) is the amount of longitudinal force required to shear the sod pad. Commercially available cultivars evaluated included ‘Tifway’, ‘Latitude 36’, ‘Celebration’, ‘Quickstand’, ‘Astro’, ‘Patriot’ and ‘Tifgrand’ and were considered standards. The SHQ (a qualitative parameter) was evaluated using a 1 to 5 scale with 1 = complete separation during handling, not harvestable, 3 = moderate separation (cracking), suggested minimum acceptable rating, and 5 = no cracking, excellent quality. Sod tensile strength (a quantitative parameter) was measured in kg dm^-2 as the peak force required to shear the sod pad using a sod tensile strength measuring device. Three sod harvests were conducted. The harvests were conducted at 14 months after planting, second year after 100% green up and at 24 months after planting. The harvest date and entry had a significant effect on STS. The Oklahoma State University’s experimental variety ‘OKC 1302’ and '12-TSB-1' had higher mean STS than the standard Patriot but were lower than the STS of the other standards Latitude 36, Tifway, Astro and Tigrand. The seeded variety ‘PST-R6T9S’ had the lowest STS and SHQ. The results of this research will help in comparative ranking of the experimental and commercial lines for their STS and SHQ and will aid product developers in decision making concerning possible commercializing of the experimental cultivars tested.