Management of Echinochloa polystachya in Drill-seeded Rice

Abstract

A study was conducted in 2004 and 2005 near Crowley, LA to evaluate soil-applied herbicides labeled for barnyardgrass control in rice for activity on Echinochloa polystachya. The study included: clomazone applied preemergence (PRE), clomazone plus quinclorac applied PRE, pendimethalin plus quinclorac applied delayed PRE, imazethapyr applied PRE, and mesotrione applied PRE. Each soil applied herbicide program was followed by cyhalofop applied postemergence (POST). Averaged over 7 to 49 DAT, all of the herbicide programs controlled barnyardgrass at least 87%. Averaged over herbicide program, barnyardgrass control was 91 to 93% from 28 to 42 DAT; however, control at all evaluations was at least 85%. The herbicide programs with a single application of clomazone or imazethapyr applied PRE, or pendimethalin plus quinclorac applied delayed PRE controlled E. polystachya 78 to 81%. Control was 72% for programs containing mesotrione or clomazone plus quinclorac applied PRE. The combination of clomazone and quinclorac PRE followed by (fb) cyhalofop POST controlled E. polystachya 72% while clomazone PRE fb cyhalofop POST controlled the weed 80%.