Preemergence (PRE) and postemergence (POST) herbicides registered for large crabgrass control were evaluated for control of Japanese stiltgrass, an invasive, nonnative C4 annual grass. Benefin plus oryzalin, dithiopyr, isoxaben plus trifluralin, oryzalin, oxadiazon, pendimethalin, prodiamine, or trifluralin applied PRE controlled Japanese stiltgrass 87% or greater 8 wk after treatment. Benefin plus trifluralin, metolachlor, or napropamide applied PRE were less effective (78, 39, and 59% control, respectively). Single POST applications of clethodim, fenoxaprop-P, fluazifop-P, or sethoxydim controlled Japanese stiltgrass 50 to 88%. These herbicides applied twice provided 82 to 99% control. Single POST applications of glufosinate controlled Japanese stiltgrass 82 to 85%, whereas two applications provided complete control. Single POST applications of glyphosate were just as effective as two applications in controlling Japanese stiltgrass. Dithiopyr, MSMA, and quinclorac applied POST were ineffective on Japanese stiltgrass. All PRE and POST herbicides tested were equally or more effective on Japanese stiltgrass than on large crabgrass, with the exception of metolachlor applied PRE and dithiopyr or quinclorac applied POST.
Nomenclature: Benefin; clethodim; dithiopyr; fenoxaprop-P; fluazifop-P; glufosinate; glyphosate; isoxaben; metolachlor; MSMA; napropamide; oryzalin; oxadiazon; pendimethalin; prodiamine; quinclorac; sethoxydim; trifluralin; Japanese stiltgrass, Microstegium vimineum (Trin.) A. Camus #3 MCGVM; large crabgrass, Digitaria sanguinalis (L.) Scop. # DIGSA.
Additional index words: Annual jewgrass, bamboograss, flexible sesagrass, invasive plant, Japanese grass, Mary's grass, Nepalese browntop.
Abbreviations: DAT, days after treatment; POST, postemergence; PRE, preemergence; WAT, weeks after treatment.