Shade, height of cut, and plant growth regulator effects on bermudagrass and zoysiagrass putting greens

Abstract Warm‐season turfgrasses, especially hybrid bermudagrass ( Cynodon dactylon (L.) Pers × Cynodon transvaalensis Burtt‐Davy), continue to be widely used on golf course putting greens in tropical and subtropical climates globally and are also gaining popularity in the transition zone region of the United States. Hybrid bermudagrass produces a high‐quality putting green surface; however, it has relatively poor shade and cold tolerance. Recently, fine‐textured zoysiagrass ( Zoysia spp .) cultivars have been released and may be another potential option for golf course putting greens, especially since zoysiagrass is generally considered more shade tolerant than bermudagrass. “Lazer (DALZ 1308)” zoysiagrass ( Zoysia matrella (L.) Merrill × Zoysia minima (Colenso) Zotov) is a new, fine‐textured zoysiagrass that may have the potential to produce high‐quality putting green surfaces in transition zone environments. The objective of this 2‐year field trial was to compare Lazer zoysiagrass to TifEagle bermudagrass under varying light levels (0%, 20%, 40%, 60%, and 80% shade) and management practices to determine the minimum daily light integral (DLI) requirements and surface playability characteristics (ball roll distance and surface firmness) for each species. Species plots were split with two mowing heights (2.5 and 3.2 mm) and further split with or without weekly applications of the plant growth regulator, trinexapac‐ethyl. Lazer demonstrated significantly greater shade tolerance than TifEagle. The minimum DLI requirement for Lazer was generally about 10 mol m −2 day −1 less than TifEagle. Surface firmness was also greater for Lazer zoysiagrass, while TifEagle consistently produced greater ball roll distances than Lazer. Results from this trial demonstrate that Lazer zoysiagrass can produce acceptable putting green conditions and is better adapted than TifEagle to moderate shade conditions.