Nitrogen rate and cultivar effects on zoysiagrass putting greens in the transition zone

Abstract

Zoysiagrasses (Zoysia spp. Willd.) have been predominately used as turfgrass for residential and commercial lawns in addition to golf course fairways and tees due to reduced input requirements compared with bermudagrass (Cynodon spp.). The recent development of fine-textured zoysiagrass cultivars has sparked interest in using zoysiagrass on putting greens. A complete-factorial field experiment was conducted over replicate trials in Knoxville, TN to evaluate the putting green performance and quality of four zoysiagrass cultivars under two nitrogen (N) rates in the transition zone. Four zoysiagrass cultivars (Lazer, M85, Prizm, and Trinity) were treated with either 0.93 or 1.9 g N m−2 every 2 wk over a 16-wk period from June to September in 2020 and 2021. Ball roll distance, surface firmness, and turfgrass color were evaluated weekly. Lazer and M85 consistently provided the greatest ball roll distance and turfgrass color over both seasons, whereas Prizm occasionally exhibited similar performance and color. Lazer produced the firmest greens, whereas Prizm exhibited the softest surface. Trinity had reduced turfgrass color over both years, implying that it should not be used on putting surfaces. The 1.9 g N m−2 rate reduced ball roll distance and increased turfgrass color but had limited effect on surface firmness. Applying 0.93 g N m−2 increased ball roll distance, reduced turfgrass color, and maintained surface firmness similar to 1.9 g N m−2. Additionally, cultivar selection will likely affect putting green performance, playability, and quality.