POST Control of Carolina Redroot (Lachnanthes caroliniana)

Abstract

Greenhouse studies were conducted in 2012 in Raleigh, NC to determine Carolina redroot control by ten POST herbicides. Paraquat and glufosinate provided the greatest control 14 (73 and 64%, respectively) and 25 d (82 and 68%, respectively) after treatment (DAT), but control declined between 25 and 63 DAT (72 and 59%, respectively). Glyphosate provided minimal control 14 DAT (18%), and control increased from 14 to 25 DAT (46%) and 25 to 63 DAT (69%). Control of Carolina redroot roots and rhizomes (roots/rhizomes) was greatest in plants treated with paraquat (91%), glyphosate (88%), glufosinate (73%), hexazinone (62%), diuron (60%). Nontreated Carolina redroot shoot and root/rhizome dry weight were 8.3 and 7.6 g, respectively. Paraquat, glufosinate, glyphosate, and diuron reduced both shoot and root/rhizome dry weight (3.1 and 0.7 g, 5.1 and 2.7 g, 5.4 and 1.0, 5.7 and 1.6 g, respectively). Hexazinone reduced root/rhizome dry weight (2.7 g). Fomesafen reduced shoot dry weight (6.1 g), but did not reduce root/rhizome dry weight. Paraquat, glufosinate, glyphosate, hexazinone, diuron, and clopyralid treatments resulted in reduced incidence of Carolina redroot flowering and anthesis.