Effect of Various Hydraulic Fluids on Creeping Bentgrass Injury.

Hydraulic fluid leaks from turfgrass equipment can result in significant long term damage to turfgrass swards. While alternatives to conventional hydraulic fluids (i.e., petroleum oil-based oils) are available, there is limited research-based data regarding the safety of these products to creeping bentgrass (Agrostis stolonifera L.; CBG). Previous work has shown that vegetable oils and biodegradable plant seed oils (polyol ester-based oils) had less long term effects when compared to petroleum-based oils in warm and cool season turfgrasses, respectively (Berndt, 2006; Elliott and Prevatte, 1995; Gaussoin, 1998).  While the results of these studies provide valuable information, there has been limited research on the safety of various synthetic fluids on CBG.  The objectives of these studies were to: 1) compare the safety of several synthetic hydraulic fluids when applied to CBG; 2) determine the influence of post-application remediation on reducing injury; and 3) identify the potential influence of water source on post-application remediation.  Two field studies were conducted at the Valentine Turfgrass Research Center located in University Park, PA between 2011 and 2012.  Studies were conducted on a ‘Penn A-4’ CBG research putting green. Hydraulic fluids evaluated included; two synthetic ester-based fluids, a synthetic water soluble polyakleylene glycol-based fluid, and a petroleum oil-based fluid. Injury to CBG from a simulated hydraulic fluid spill varied among products and remediation techniques.  All products resulted in unacceptable injury when initially applied. Turfgrass recovery, however, was possible within 14 to 20 days when post application water or soap remediation was implemented on CBG treated with water soluble polyalkylene glycol-based synthetic hydraulic fluid. Creeping bentgrass recovery was not observed within 30 to 38 days within plots treated with synthetic ester or petroleum-based fluids, regardless of remediation.  Water source did not influence creeping bentgrass recovery regardless of fluid evaluated.