Phytotoxicity Screen of Soil Surfactants

March 23, 2005

Summary: A non-replicated screening study was conducted on a putting green of Poa annua and bentgrass (75%/25%) to determine the relative phytotoxicity of experimental products ACA 1820 and ACA 1847, when compared against the commercial standard, Primer.  Key results include:

• When applied at the standard application rate of 6 oz/1000 sq ft, none of the products tested produced phytotoxicity on either Poa annua or bentgrass mowed at greens height.
• Linear regression analysis indicates that rates as high as 10.9 - 11.8 oz/1000 sq ft (for ACA 1820) and as high as 12.5 oz/1000 sq ft (for ACA 1847) could be used while maintaining turf at acceptable levels of quality (quality rating of 6.5 or higher).
• Based on the linear regression equations, only very high rates of these products (20 - 26.5 oz/1000 sq ft for ACA 1820 and 28.1 oz/1000sq ft for ACA 1847) would result in unacceptable damage to turf
• There was a significant negative correlation between rate and turf quality for both products on certain rating dates, however, indicating that as expected, higher rates of these products can produce increasingly higher levels of turf damage.
• There was a lag time in the appearance of this damage; for ACA 1820, significant damage was apparent only after 2 days (the turf appears to have begun to recover by 7 days after treatment), while for ACA 1847,the damage took 7 days to become apparent, and was not obvious at any of the earlier evaluation dates.

Printable version of full report

Principal Investigators: Wendy Gelernter, Ph.D. and Larry J. Stowell, Ph.D., CPPP, CPAg

Cooperator: Candice Combs, Balboa Park Golf Club

Sponsor:  Stan Kostka, Aquatrols