Preemergence and Postemergence Control of Japanese Stiltgrass (Microstegium vimineum)¹

Abstract

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.

Japanese Stiltgrass Control with Herbicides in Cool-Season Grass Forages

“…Gover et al (2003) reported complete (100%) control with pendimethalin at 2 lb/acre, and Derr (1999) reported > 75% control. Quinclorac resulted in < 10% control 4 WAT (Judge et al, 2005a), which is corroborated by Brewer et al (2017). Quinclorac resulted in < 10% control 4 WAT (Judge et al, 2005a), which is corroborated by Brewer et al (2017).…”

“…Livestock do not graze Japanese stiltgrass unless there are no alternative forages, such as during a drought (authors' observation). Hand-weeding, mechanical methods, and herbicides are all effective forms of control and reduce seed production when conducted before flowering (Askew and Willis, 2007;Gover et al, 2003;Judge et al, 2005aJudge et al, , 2005bJudge et al, , 2008Ward and Mervosh, 2012). These studies indicate the primary goal of any Japanese stiltgrass management program should be to reduce or eliminate seed input into the soil seed bank as seed is necessary for long-term persistence (Askew and Willis, 2007;Fairbrothers and Gray, 1972;Gover et al, 2003;Mehrhoff, 2000;Ward and Mervosh, 2012).…”

“…Causey et al (2018) reported aminopyralid at 0.86 oz/ acre resulted in increased Japanese stiltgrass ground cover relative to a nontreated control, but Gover et al (2014) reported a aminopyralid at 1.71 oz/acre reduced ground cover to 5 from 50% in the nontreated control. Several researchers report that glyphosate controls emerged Japanese stiltgrass > 90% (Askew and Willis, 2007;Gover et al, 2003;Judge et al, 2005aJudge et al, , 2008Ward and Mervosh, 2012). Aminocyclopyrachlor has been reported to control Japanese stiltgrass well (Causey et al, 2018;Gover et al, 2014) but currently is not labeled for use in forages.…”

Japanese Stiltgrass (Microstegium vimineum) Management for Restoration of Native Plant Communities

“…Sethoxydim has been shown to control Japanese stiltgrass POST (Gover et al 2003;Jones et al 2004;Judge et al 2005a;Judge et al 2005b), but also controls a broader spectrum of grasses including both annual and perennial grasses (Senseman 2007). When considering how management of Japanese stiltgrass impacts desirable native vegetation such as perennial grasses, perhaps fenoxaprop-P will have fewer nontarget impacts.…”

“…When considering how management of Japanese stiltgrass impacts desirable native vegetation such as perennial grasses, perhaps fenoxaprop-P will have fewer nontarget impacts. Fenoxaprop-P has also been shown to control Japanese stiltgrass POST (Jones et al 2004;Judge et al 2005a;Judge et al 2005b) and does not injure dicots, rushes (Juncaceae), sedges (Cyperaceae), or most perennial grasses (Poaceae) (Senseman 2007).…”