1/24/2023 - By Dr. Raymond Snyder

Study:                   Evaluating effect of potassium silicate for improving creeping bentgrass putting green quality, physiological fitness, and root growth during Summer drought stress.

Location:             Virginia Tech Turfgrass Research Center, Blacksburg, VA.

Collaborator:     Xunzhong Zhang, Virginia Tech University

Date:                     June 8, 2022 – August 31, 2022

Details:                This study was carried out on the creeping bentgrass putting green at Virginia Tech Turfgrass Research Center.  A randomized block design with 4 replications was used.  Plot size was 5 x 6 ft.  Regular mowing and irrigation were performed.  The rate of N fertilization (soluble 28-8-18) was the same across all treatments.  Treatments were applied biweekly.  The trial lasted for 12 weeks.  Data collection occurred at day 0, 14, 28, 42, 56, 70, and 84 days after initial treatments.  From June 21 to June 30 and from July 11 to July 20 irrigation was withheld to allow for gradual decline of soil water content, inducing decline in leaf color and turf quality.  At the beginning, mid, 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 bentgrass turf quality and Summer stress tolerance by improving photosynthetic function (higher photochemical efficiency and chlorophyll content), antioxidant capacity (higher carotenoids content and 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.