Monday, November 13, 2006 - 1:15 PM

Trinexapac-ethyl Formulations Influence Bispyribac-Sodium Efficacy and Foliar Absorption.

Patrick Mccullough and Steve Hart. Rutgers Univ., 59 Dudley Rd, 59 Dudley Rd, New Brunswick, NJ 08901, United States of America

Bispyribac-sodium (BS) selectively controls annual bluegrass in creeping bentgrass but turf chlorosis following applications warrants research to mitigate these effects without reducing efficacy for annual bluegrass control.  Field experiments were conducted in 2005 and 2006 on creeping bentgrass and annual bluegrass fields in New Jersey to investigate efficacy of BS as influenced by a plant growth regulator, trinexapac-ethyl (TE).  Applications of TE at 50 g/ha did not reduce efficacy for annual bluegrass control from BS at 111 g/ha while TE applied before and tank mixed with BS reduced creeping bentgrass chlorosis from sequential applications.  Tank mixing BS with TE in emulsifiable concentration, microencapsulated concentration, or as a wettable powder provided similar efficacy with BS.  In laboratory experiments, increased TE rates increased 14C-BS foliar absorption but differences among TE formulations were not detected.