Influence of cultivation method, seeding rate, and fertilizer rate on the establishment of creeping bentgrass for putting green renovation

During putting green renovation in northern regions of the United States, golf course superintendents must select a method to quickly establish creeping bentgrass (Agrostis stolonifera L.)(CBG). This study aimed to assess the impact of cultivation method, seeding rate, and cumulative starter fertilizer rate on CBG establishment during putting green renovation. A field study on putting greens at the Joseph Valentine Turfgrass Research Center (University Park, PA) was initiated in late summer–autumn of 2017 and 2018. Cultivation treatments included slicing + 0.5-inch hollow tines, slicing + 0.25-inch hollow tines, slicing only, surface dimpling with the Jobsaver attachment, and no cultivation. Seeding rates included 0.75 and 1.5 lb seed 1,000 ft⁻² with a 50–50 blend of ‘Penn A-1’ and ‘Penn A-4’ CBG. Cumulative starter fertilizer treatments were 0.5–0.4–0.3, 1.0–0.9–0.6, or 1.5–1.3–0.8 lb N–P–K 1,000 ft⁻². Seedling vigor and turfgrass cover were visually assessed at 1 wk and 6, 10, and 36 wk after seeding, respectively. Slicing alone produced turfgrass cover equal to or greater than slicing + hollow-tine cultivation. At the high seeding rate, surface dimpling produced similar turfgrass cover to treatments involving slicing. The 1.5 lb 1,000 ft⁻² seeding rate increased the turfgrass cover of CBG compared with 0.75 lb 1,000 ft⁻². Establishment rate improved as cumulative fertilizer rates increased. The results indicate that slicing alone is effective for establishing CBG during late summer and autumn in sand rootzone putting green renovation programs and may be more cost-effective than core cultivation.