Hostname: page-component-7b7567c8c-tnzcf Total loading time: 0 Render date: 2026-11-13T22:53:11.516Z Has data issue: false hasContentIssue false

ALS–Resistant Annual Sedge (Cyperus compressus)Confirmed in Turfgrass

Published online by Cambridge University Press:  20 January 2017

Patrick E. McCullough*
Affiliation:
Crop and Soil Sciences Department, University of Georgia, Griffin, GA 30223
Jialin Yu
Affiliation:
Crop and Soil Sciences Department, University of Georgia, Griffin, GA 30223
J. Scott McElroy
Affiliation:
Department of Crop, Soil, and Environmental Sciences, Auburn University, Auburn, AL 36849
S. Chen
Affiliation:
Department of Crop, Soil, and Environmental Sciences, Auburn University, Auburn, AL 36849
H. Zhang
Affiliation:
Department of Crop, Soil, and Environmental Sciences, Auburn University, Auburn, AL 36849
Timothy L. Grey
Affiliation:
Crop and Soil Sciences Department, University of Georgia, Griffin, GA 30223
Mark A. Czarnota
Affiliation:
Horticulture Department, University of Georgia, Griffin, GA 30223
*
Corresponding author's E-mail: pmccull@uga.edu
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the 'Save PDF' action button.

Acetolactate synthase (ALS) inhibitors are widely used for POST control ofsedges in turfgrass. A suspected resistant (R) biotype of annual sedge wascollected from a bermudagrass turf in Georgia with a history of exclusiveuse of halosulfuron. Research was conducted to evaluate the resistance levelof this biotype to halosulfuron, efficacy of ALS-inhibiting herbicides andother mechanisms of action for control, and the molecular and physiologicalbasis for resistance. In greenhouse experiments, the halosulfuron raterequired to reduce shoot biomass 50% in comparison with the nontreated at 8wk after treatment (WAT) were 8 and > 1,120 g ai ha−1 for theS (susceptible) and R biotypes, respectively. Imazapic, sulfosulfuron, andtrifloxysulfuron reduced biomass of the S biotype greater than 60% at 8 WAT,but biomass was reduced less than 20% for the R biotype. Glufosinate,glyphosate, MSMA, and sulfentrazone reduced shoot biomass of the R biotypeby 93, 86, 97, and 45%, respectively. In laboratory experiments, thehalosulfuron concentration required to inhibit ALS activity by 50% inexcised leaf tissues was 5.8 and > 1,000 μM for the S and R biotypes,respectively. Gene sequencing of the R biotype revealed a Pro-197-Sersubstitution that confers resistance to ALS inhibitors. This is the firstreport of ALS-inhibitor resistance in annual sedge and herbicide resistancein a sedge species from a turfgrass system.

Information

Type
Physiology/Chemistry/Biochemistry
Copyright
Copyright © Weed Science Society of America