INTERNATIONAL HERBICIDE-RESISTANT WEED DATABASE

HRAC GROUP 2 (LEGACY B) RESISTANT MIZOHAKOBE (WATERWORT)
(Elatine triandra var. pedicellata)

Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)

Japan, Saitama
INTRODUCTION MIZOHAKOBE (WATERWORT)
Mizohakobe (Waterwort) (Elatine triandra var. pedicellata) is a dicot weed in the Elatinaceae family.  In Japan this weed first evolved resistance to Group 2 (Legacy B) herbicides in 1997 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 imazosulfuron 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.

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QUIK STATS (last updated Jan 08, 2014 )

Common NameMizohakobe (Waterwort)
SpeciesElatine triandra var. pedicellata
GroupInhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
Herbicidesimazosulfuron
LocationJapan, Saitama
Year1997
Situation(s)Rice
Contributors - (Alphabetically)Kazuyuki Itoh 
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ACADEMIC ASPECTS

Confirmation Tests

Greenhouse, and Laboratory trials comparing a known susceptible Mizohakobe (Waterwort) biotype with this Mizohakobe (Waterwort) 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 Mizohakobe (Waterwort) 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 Mizohakobe (Waterwort) from Japan please update the database.
 
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CONTRIBUTING WEED SCIENTISTS

KAZUYUKI ITOH
Professor
Kobe University
Graduate School of Agricultural Science
１-１ Rokkodaicho
Kobe, 657-0013, Hyogo
Japan
Email Kazuyuki Itoh

ACKNOWLEDGEMENTS

The Herbicide Resistance Action Committee, The Weed Science Society of America, and weed scientists in Japan have been instrumental in providing you this information. Particular thanks is given to Kazuyuki Itoh for providing detailed information.
Herbicide Resistant Mizohakobe (Waterwort) Globally
(Elatine triandra var. pedicellata)
Herbicide Resistant Mizohakobe (Waterwort) Globally
(Elatine triandra var. pedicellata)
Drag a column header and drop it here to group by that column
Herbicide Resistant Mizohakobe (Waterwort) Globally
(Elatine triandra var. pedicellata)
#CountryFirstYearSituationActive IngredientsSite of Action
1 JapanJapan 1997 Rice imazosulfuron 25 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
 		210Elatine triandra var. pedicellataMizohakobe (Waterwort)5142
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HRAC Global Heap, I.  The International Herbicide-Resistant Weed Database.  Online.  Tuesday, September 22, 2026.  Available at  www.weedscience.org

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