Wetting Agents and Their Effect on Surface Firmness and Winter Health of Creeping Bentgrass Putting Greens.

Wetting agents are tools that many golf course superintendents use to manage soil moisture. There has been an increase in wetting agent product claims that their use improves surface firmness and promotes winter hardiness; however, research on these benefits is limited. The objective of this experiment was to determine the impact of season-long wetting agent programs on the surface firmness of putting greens and to evaluate winter health benefits from a late season wetting agent application. In 2014 the study was conducted on a 12 year-old USGA putting green seeded with ‘Alpha’ creeping bentgrass (Agrostis stolonifera) and in 2015 on 'A-4' creeping bentgrass. Monthly applications with thirteen commercially available wetting agents and wetting agent combinations were initiated in early-May of 2014 and 2015 and applied  through mid-October. Data collection included soil moisture readings, surface firmness, chlorophyll index, turf quality and  water droplet penetration times. In 2014 very few differences were seen in surface firmness between wetting agent treatments. Winter hardiness benefits or lack of benefits were not seen from the 2014 treatments, but spring water drop penetration tests indicated that Cascade Plus, Fleet, Revolution and the Cascade Plus/Duplex combination persisted in the soil throughout the winter months and into the spring. Results from 2015 were different from 2014 and demonstrated that some wetting agents can provide a firmer playing surface under wet conditions.