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United States Department of Agriculture

Agricultural Research Service

Title: Tribenuron Resistance in Accessions of Wild Sunflower Collected in Canada

Authors
item Miller, Jerry
item Seiler, Gerald

Submitted to: Proceedings Sunflower Research Workshop
Publication Type: Proceedings
Publication Acceptance Date: February 7, 2005
Publication Date: February 7, 2005
Citation: Miller, J.F., Seiler, G.J. 2005. Tribenuron resistance in accessions of wild sunflower collected in Canada. Proceedings Sunflower Research Workshop. Available: http://www.sunflowernsa.com/research/research-workshop/documents/Miller_Tribenuron_05.PDF

Interpretive Summary: Tribenuron (Express) herbicide resistance was found in 57% of native Helianthus accessions collected in the United States in 2003. Sulfonylurea herbicides (which include tribenuron) were distributed in Canada for broadleaf weed control in cereal crops as early as 1982. It would be of great interest to sunflower researchers and industry to know if resistant native accessions had developed in Canada before Express resistant hybrids are released to producers of sunflower in Canada. The objective of this investigation was to determine if any of the accessions collected in a plant exploration of wild sunflower in 1994 had resistance to tribenuron. Resistance to tribenuron was found in accessions of Helianthus annuus collected in all three provinces of Canada, Alberta, Saskatchewan, and Manitoba. No resistance was found in the Helianthus petiolaris accessions. Of the H. annuus accessions tested, 52% had resistant plants. Within the accessions found to have resistance, the highest percentage of resistant plants in an accession was 5.9%. The average resistance found in plants tested was 3.4%. This investigation clearly indicates that tribenuron resistance in wild sunflower is not a novel trait, that this resistance was widespread among accessions collected across the provinces of Canada, that resistance occurred in low frequencies in those accessions, and the resistance occurred in the environment before release of Express tolerant sunflower hybrids for commercial production in Canada.

Technical Abstract: Tribenuron (Express) herbicide resistance was found in 57% of native Helianthus accessions collected in the United States in 2003. It would be of great interest to sunflower researchers and industry to know if resistant native accessions had developed in Canada before Express resistant hybrids are released to producers of sunflower in Canada. The objective of this investigation was to determine if any of the accessions collected in a plant exploration of wild sunflower in 1994 had resistance to tribenuron. Resistance to tribenuron was found in accessions of Helianthus annuus collected in all three provinces of Canada, Alberta, Saskatchewan, and Manitoba. No resistance was found in the Helianthus petiolaris accessions. Of the H. annuus accessions tested, 52% had resistant plants. Within the accessions found to have resistance, the highest percentage of resistant plants in an accession was 5.9%. The average resistance found in plants tested was 3.4%. This investigation clearly indicates that tribenuron resistance in wild sunflower is not a novel trait, that this resistance was widespread among accessions collected across the provinces of Canada, that resistance occurred in low frequencies in those accessions, and the resistance occurred in the environment before release of Express tolerant sunflower hybrids for commercial production in Canada.

Last Modified: 10/25/2014
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