<b>HRAC Group 2</b> <font size='2'> (Legacy B) </font> resistant Cyperus difformis from South Korea

INTERNATIONAL HERBICIDE-RESISTANT WEED DATABASE

HRAC GROUP 2 (LEGACY B) RESISTANT SMALLFLOWER UMBRELLA SEDGE
(Cyperus difformis)

Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)

South Korea

INTRODUCTION		SMALLFLOWER UMBRELLA SEDGE
Smallflower Umbrella Sedge (Cyperus difformis) is a monocot weed in the Cyperaceae family. In South Korea this weed first evolved resistance to Group 2 (Legacy B) herbicides in 2002 and infests Rice. Group 2 (Legacy B) herbicides are known as Inhibition of Acetolactate Synthase (Inhibition of Acetolactate Synthase ). Research has shown that these particular biotypes are resistant to azimsulfuron, bensulfuron-methyl, cinosulfuron, cyclosulfamuron, ethoxysulfuron, halosulfuron-methyl, imazosulfuron, and pyrazosulfuron-ethyl and they may be cross-resistant to other Group 2 (Legacy B) herbicides. The 'Group' letters/numbers that you see throughout this web site refer to the classification of herbicides by their site of action. To see a full list of herbicides and HRAC herbicide classifications click here.

QUIK STATS (last updated Dec 27, 2002 )
Common Name	Smallflower Umbrella Sedge
Species	Cyperus difformis
Group	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
Herbicides	azimsulfuron, bensulfuron-methyl, cinosulfuron, cyclosulfamuron, ethoxysulfuron, halosulfuron-methyl, imazosulfuron, and pyrazosulfuron-ethyl
Location	South Korea
Year	2002
Situation(s)	Rice
Contributors - (Alphabetically)	Il-Bin Im
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NOTES ABOUT THIS BIOTYPE

AREAS FOUND

Il-Bin Im

South-West of Korea

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ACADEMIC ASPECTS

Confirmation Tests

Greenhouse trials comparing a known susceptible Smallflower Umbrella Sedge biotype with this Smallflower Umbrella Sedge biotype have been used to confirm resistance. For further information on the tests conducted please contact the local weed scientists that provided this information.

Genetics

Genetic studies on HRAC Group 2 resistant Smallflower Umbrella Sedge have not been reported to the site. There may be a note below or an article discussing the genetics of this biotype in the Fact Sheets and Other Literature

Mechanism of Resistance

The mechanism of resistance for this biotype is either unknown or has not been entered in the database. If you know anything about the mechanism of resistance for this biotype then please update the database.

Relative Fitness

There is no record of differences in fitness or competitiveness of these resistant biotypes when compared to that of normal susceptible biotypes. If you have any information pertaining to the fitness of Group 2 (Legacy B) resistant Smallflower Umbrella Sedge from South Korea please update the database.

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CONTRIBUTING WEED SCIENTISTS

IL-BIN IM

CRO Bio-Plant Environment Research Center Weed Control 5306-1. BI Center. Honam University Kwangsan, 506-714, Kwangju South Korea Email Il-Bin Im Web : Web Site Link

ACKNOWLEDGEMENTS
The Herbicide Resistance Action Committee, The Weed Science Society of America, and weed scientists in South Korea have been instrumental in providing you this information. Particular thanks is given to Il-Bin Im for providing detailed information.

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Herbicide Resistant Smallflower Umbrella Sedge Globally
(Cyperus difformis)

Country

FirstYear

Situation

Active Ingredients

Site of Action

Australia (New South Wales )

1994

Rice

bensulfuron-methyl