Tuesday, November 6, 2007
171-2

‘L-93' Creeping Bentgrass Responses to Various Levels of Potassium and Wetting Agents.

Williams Sarvis, Haibo Liu, Lambert McCarty, Bill Bauerle, and Joe Toler. 253 P&A Building, Clemson University, Clemson University, Department of Horticulture, Clemson, SC 29634-0319

As a majority of turfgrass managers in the transition zone rely on creeping bentgrass putting surfaces on their golf courses, they become overwhelmed by bentgrass summer decline due to high temperature stress. Potassium is currently in high interest for its ability to reduce summer stress by a possibility of stomatal regulation. Wetting agents are also being explored for their ability to reduce hydrophobicity of the soil profile. Wetting agents have also been shown to provide increased uptake of essential turfgrass nutrients.  To examine the interaction and possible ability of the two treatments, a two year field study is underway on a ‘L-93’ Creeping bentgrass with treatments consisting of liquid potassium or granular potassium (97.64 kg K/ha and 195.28 kg K/ha), and applications of a wetting agent (Revolution wetting agent produced by Aquatrols Corp., at 18.8 kg/ha monthly).  Measurements are currently being taken on leaf and root tissues nutrient concentrations, clipping yield, root weight, soil moisture, localized dry spot using the Water Droplet Method, and turf quality (1-9, 1 being dead, 7 being acceptable and 9 being optimal).  The results show: 1) Wetting agent treatments consistently reduce the soil hydrophobicity in both depths of  1.5 and 3.0 cm; 2) The greatest turf quality was found under the treatment with 195.28 kg K/ha granular K without wetting agent in 2006 and with wetting agent in 2007 and poorest turf quality were found treated with 195.28 kg K/ha in liquid form with a possibility of phytotoxicity; 3) Clipping yields were not found different among all treatments but  the leaf tissue K contents of treatments with 195.28 kg K/ha in liquid form were significantly higher than others; and 4) Treatments of 195.28 kg K/ha demonstrated slightly photo-toxicity by reducing dry root mass.