Combining Glyphosate With Burning or Mowing Improves Control of Yellow Bluestem (Bothriochloa ischaemum)

Abstract

The invasive yellow bluestem (Bothriochloa ischaemum [L.] Keng) threatens native biodiversity, and its control is of interest to land managers involved in restoration of invaded grasslands. We used single, double, and triple applications of glyphosate (2.125 kg ai Á ha À1 Á application À1) over the course of one growing season in combinations at different timings (early, middle, late season) with and without a mechanical treatment of mowing or burning to determine the most effective control method. One year after treatment, burning and mowing prior to a mid-season single or double early, middle, and/or late season herbicide application resulted in a similar level of control of yellow bluestem relative to a triple herbicide application, all of which had greater control relative to herbicide treatment alone. Reproductive tiller density and visual obstruction increased 2 yr after treatment with two herbicide treatments applied either early and middle season or early and late season, but it was prevented with burning and mowing prior to herbicide application. With the exception of three herbicide applications, combining burning or mowing with herbicide applications provided more effective control of yellow bluestem than any individual herbicide applications. Burning or mowing likely improves glyphosate effectiveness by altering the invasive grass structure so that plants are clear of standing dead and have shorter, active regrowth to enhance herbicide effectiveness. During restoration projects requiring control of invasive yellow bluestem, an effective management option is a combination of mechanical and chemical control.

Long‐term late season mowing maintains diversity in southernUStallgrass prairie invaded byBothriochloa ischaemum

“…; Robertson et al. ). Although the direct effect of mowing was not significant, these studies fail to consider any possible long‐term effects of mowing on BOIS cover.…”

Meta-Analysis of Exotic Forages as Invasive Plants in Complex Multi-Functioning Landscapes

“…Research funded in part by the U.S. Department of Agriculture also reflects conflicting goals. For example, research on forage characteristics of Old World bluestems (Cui et al 2013) and control of invasive Old World bluestems (Robertson et al 2013) conflicts, and both studies were conducted in the Southern Great Plains of the United States. State-and-transition models used to guide management of ecological sites must also increase attention paid to the invasion of exotic herbaceous plants as only 13% of current Ecological Site Descriptions account for these species (Twidwell et al 2013).…”

Managing invasive plants on Great Plains grasslands: A discussion of current challenges

“…Because fire is a relatively nonselective tool for controlling invasive species, proper timing of application may be important: early (cool-season) fires are often used to target cool-season invasives in warm-season-dominated tallgrass prairies ( Wilson and Stubbendieck 1997 ;Brudvig et al 2007 ). Growing-season fire targets warm-season yellow bluestem in the southern Great Plains ( Simmons et al 2007 ;Havill et al 2015 ) and cool-season annual grasses in Montana ( Vermeire et al 2011 ), and it may be timed to enhance herbicide effectiveness ( Robertson et al 2013 ). Native species are largely adapted to growing-season fire and thus are not adversely affected.…”