Translator Disclaimer
1 October 2006 Patterns Of Resistance To Als Herbicides In Smallflower Umbrella Sedge (Cyperus Difformis) And Ricefield Bulrush (Schoenoplectus Mucronatus)
Roberto Busi, Francesco Vidotto, Albert J. Fischer, MarÍa D. Osuna, Rafael De Prado, Aldo Ferrero
Author Affiliations +
Abstract

Biotypes of smallflower umbrella sedge and ricefield bulrush resistant to acetolactate synthase (ALS)-inhibiting herbicides have been reported in several rice areas of the world. Here, we present results of a study conducted on whole plants of seven smallflower umbrella sedge and four ricefield bulrush biotypes collected in Italian, Spanish, and Californian rice fields to evaluate cross-resistance to ALS herbicides in these important weeds of temperate rice. The following herbicides were tested: bensulfuron-methyl, halosulfuron, cinosulfuron, imazamox, and bispyribac-sodium. The smallflower umbrella sedge and ricefield bulrush biotypes studied exhibited different cross-resistance patterns, some of which have not been previously reported. The Italian smallflower umbrella sedge biotype was cross-resistant to bensulfuron-methyl, cinosulfuron, imazamox, and bispyribac-sodium, but was susceptible to halosulfuron. One smallflower umbrella sedge biotype from California was also resistant to bensulfuron-methyl, imazamox, and bispyribac-sodium, but had a lower level of resistance to halosulfuron. In contrast, the second smallflower umbrella sedge biotype from California was strongly resistant to halosulfuron and was also resistant to bensulfuron-methyl and bispyribac-sodium, but moderately resistant to imazamox. The Spanish smallflower biotype was resistant to the sulfonylurea herbicides bensulfuron-methyl and halosulfuron. Different responses were observed in ricefield bulrush. The Italian biotype was resistant to the sulfonylureas only, whereas the biotype from California exhibited broad cross-resistance to all the ALS herbicides tested. Knowledge on cross-resistance is needed to formulate herbicide use and weed management strategies for delaying the evolution of resistance to ALS herbicides in rice systems.

Nomenclature: Bensulfuron-methyl, halosulfuron, cinosulfuron, imazamox, bispyribac-sodium, smallflower umbrella sedge, Cyperus difformis L. #3 CYPDI, ricefield bulrush, Schoenoplectus mucronatus (L.) Palla (syn. Scirpus mucronatus L.) # SCMPU.

Additional index words: ALS herbicides, herbicide resistance, cross-resistance, weed management, temperate rice, rice production systems.

Abbreviations: SU, sulfonylureas; IMI, imidazolinones; TP, triazolopyrimidines; PB, pyrimidinylbenzoates; SCT, sulfonylaminocarbonyltriazolinones; FW, fresh weight; GR50, herbicide dose necessary to cause 50% growth reduction; I50, herbicide dose necessary to cause 50% inhibition; LD50, herbicide dose necessary to cause 50% mortality; R, resistant; RI, resistance index; S, susceptible.

Roberto Busi, Francesco Vidotto, Albert J. Fischer, MarÍa D. Osuna, Rafael De Prado, and Aldo Ferrero "Patterns Of Resistance To Als Herbicides In Smallflower Umbrella Sedge (Cyperus Difformis) And Ricefield Bulrush (Schoenoplectus Mucronatus)," Weed Technology 20(4), 1004-1014, (1 October 2006). https://doi.org/10.1614/WT-05-178.1
Published: 1 October 2006
JOURNAL ARTICLE
11 PAGES


Share
SHARE
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top