Date of Award
Doctor of Philosophy
Plant, Soil and Environmental Sciences
John C. Sorochan
James T. Brosnan, Brandon J. Horvath, Carrie A. Stephens
Zoysiagrasses (Zoysia spp. Willd.) are commonly used on golf course fairways and tees in addition to residential and commercial lawns due to lower input requirements relative to bermudagrass (Cynodon spp.). This has led to increased interest in using zoysiagrass for golf course putting greens; however, zoysiagrass establishment from sprigs is prolonged compared to bermudagrass. A series of experiments were conducted in glasshouses in Knoxville, TN in 2022 to evaluate the effects of environmental conditions and management practices on the establishment of Prizm zoysiagrass from sprigs. To determine the optimal soil temperature for Prizm zoysiagrass establishment, sprigs were exposed to high, medium, and low 5 cm soil temperature treatments, which were imposed via water bath. Over the 49-day study period, the high, medium, and low treatments averaged ~36 °C, ~32 °C, and ~28 °C, respectively. The medium and low treatments averaged 92% turfgrass coverage 49 days after planting (DAP) in run A, which was significantly greater than the high-soil-temperature treatment (70%). In run B, the medium soil temperature achieved 92% turfgrass coverage 44 DAP, which was significantly greater than the low (78%) and high (74%) treatments. Independent of other environmental variables, results from this study imply that an average daily 5 cm soil temperature of approximately 32 °C would likely result in the most rapid establishment of Prizm from sprigs. Another study was conducted to evaluate the effect of irrigation frequency on the establishment of Prizm sprigs. Prizm zoysiagrass was irrigated daily (3 mm) applied via four or 192 events from 06:00 a.m. to 10:00 p.m. In both experimental runs, establishment was unaffected by irrigation frequency and averaged 40% turfgrass coverage after 21.6 and 27.3 days in run A and run B, respectively. Air vapor pressure deficit during the irrigation period averaged 1.05 kPa in run A and 1.57 kPa in run B, respectively, suggesting zoysiagrass sprigs have limited sensitivity to elevated vapor pressure deficit, granted sufficient rootzone moisture is available. These conclusions indicate soil temperature is likely a prominent factor influencing zoysiagrass establishment from sprigs.
Carr, Tyler, "Methods to Hasten Zoysiagrass Establishment from Sprigs. " PhD diss., University of Tennessee, 2023.