Effect of Creeping Bentgrass Seeding Rates and Traffic on Establishment of Putting Greens during Renovation.

Significant efforts by turf breeders have led to the development of improved species and varieties of grasses with superb germination rates and physiological characteristics. Current availability and demand for these grasses will only increase their seed prices, and since renovation entails complete conversion, the need to identify cost effective, optimum creeping bentgrass (Agrostis stolonifera) seeding rates is a major challenge facing renovation projects. Evidence suggests that using higher than recommended seeding rates to quickly establish putting greens, to thwart weed competition and minimize disruption of golf rounds played in the first year following renovation, inherently exacerbate plant health issues, and disrupt early season play of golf rounds. Although speedy establishment can mitigate costs and revenue loss, the ability of excessively high shoot density turf to withstand traffic is uncertain. One method that could address these concerns is using improved creeping bentgrass varieties at, or near the lower range of the recommended seeding rates of 2.4-4.9 g/m². Our objective was to evaluate the effects of various seeding rates and traffic initiations on the establishment of a sustainable putting surface following renovation. The site was a USGA putting green (0.3-cm cut height), strip plot factorial design (6 x 4) with 8 replications at Michigan State University. Main plot factor was 'V8' creeping bentgrass seeding rate (0.6, 1.2, 2.4, 3.7, 4.9, and 9.8 g/m²) and strip plot factor was traffic initiation (May, June, and July). Plots were seeded in August 2012 and replicated in 2013. Traffic treatments were administered 3x weekly (4 passes) using a Jacobsen¨ PGM 22 with 116-"Black Widow" Softspikes¨. Preliminary results showed no significant difference (rooting strength, chlorophyll index) between 3.7 and 9.8 g/m² seeding rates. Information from this study will improve renovation principles to reduce costs without compromising turf quality.