1/31/2023 - By Dr. Raymond Snyder

Study:                   Evaluating the effects of Harrell'sMAX® Potassium Silicate for improving ‘ultradwarf’ bermudagrass putting green quality, physiological fitness, and root growth during summer drought stress.

Location:             Independence Golf Course Research Putting Green, Richmond, VA.

Collaborator:     Dr. Xunzhong Zhang, Virginia Tech University

Date:                     June 3, 2022 – August 26, 2022

Details:                This study was carried out on ‘ultradwarf’ bermudagrass putting greens at Independence Golf Course Research Putting Greens. A randomized block design with 4 replications were used, with a plot size of 6 x 6 ft, and regular mowing and irrigation were performed. The rate of N fertilization (soluble 28-8-18) was the same across all treatments, which were applied biweekly. The trial lasted for 12 total weeks with data collection occurring at days 0, 14, 28, 42, 56, 70, and 84, after initial treatments. From July 12 to July 21 and from August 8 to August 17 irrigation was withheld to allow for gradual decline of soil water content, inducing decline in leaf color and turf quality. At the beginning, middle, and end of each dry-down cycle, turf quality and leaf color were rated, and photochemical efficiency was measured. Irrigation was resumed at the end of each dry-down cycle.

                                Treatments:

1.       Fertilized control (0.15 lb N per 1000 sq ft biweekly)

2.       Potassium silicate 3 fl oz per 1000 sq ft + fertilized control

3.       Potassium silicate 6 fl oz per 1000 sq ft + fertilized control            

Results:                The results of this study suggest that potassium silicate, especially high-rate potassium silicate, may improve ‘ultradwarf’ bermudagrass turf quality, physiological fitness, and root growth characteristics. In addition, potassium silicate may improve summer stress tolerance by improving photosynthetic function (higher photochemical efficiency and chlorophyll content), antioxidant capacity (superoxide dismutase activity), and greater root system and viability. In addition, exogenous silicon application may improve summer stress tolerance by increasing leaf endogenous silicon level after multiple applications.