Hostname: page-component-76d6cb85b7-92wsb Total loading time: 0 Render date: 2026-07-21T11:34:18.398Z Has data issue: false hasContentIssue false

Resistance to Nine Herbicide Classes in a Population of Rigid Ryegrass (Lolium rigidum)

Published online by Cambridge University Press:  12 June 2017

Michael W. M. Burnet
Affiliation:
Dep. Crop Prot., Waite Agric. Res. Inst., The Univ. Adelaide, Glen Osmond, South Australia 5064
Quentin Hart
Affiliation:
Dep. Crop Prot., Waite Agric. Res. Inst., The Univ. Adelaide, Glen Osmond, South Australia 5064
Joseph A. M. Holtum
Affiliation:
Dep. Crop Prot., Waite Agric. Res. Inst., The Univ. Adelaide, Glen Osmond, South Australia 5064
Stephen B. Powles
Affiliation:
Dep. Crop Prot., Waite Agric. Res. Inst., The Univ. Adelaide, Glen Osmond, South Australia 5064

Abstract

Rigid ryegrass population VLR69 has become resistant to nine classes of herbicides after 21 yr of exposure to five herbicides in five different chemical classes. The population was exposed to diuron in 17 seasons and is resistant to diuron (4 fold) and chlorotoluron (8 fold) when compared with a reference susceptible population (VLR1). VLR69 had six seasons of exposure to chlorsulfuron and exhibits a high level of resistance to chlorsulfuron (> 20 fold) and triasulfuron (> 25 fold) and a lesser change in sensitivity to sulfometuron (7 fold); however, 4% of the population has a high level of resistance to sulfometuron. Resistance to atrazine (5 fold), simazine (6 fold), and ametryn (10 fold) was observed after five seasons of exposure to atrazine. There is a high level of resistance to all aryloxyphenoxypropionate herbicides after only two exposures to diclofop eight generations prior to testing the population. The population was cross-resistant to tralkoxydim (> 9.5 fold) and sethoxydim (1.8 fold). There was a small change in sensitivity to paraquat (1.4 fold) after three generations of exposure. The population displayed cross-resistance to: imazaquin (7 fold), imazapyr (2.5 fold), metribuzin (8.7 fold), and metolachlor (2 fold) but was susceptible to oxyfluorfen and dinitroaniline herbicides. There was also a small shift in sensitivity to tridiphane (1.6 fold).

Information

Type
Weed Biology and Ecology
Copyright
Copyright © 1994 by the Weed Science Society of America 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable