International Survey of Herbicide-Resistant Weeds

Countries Weeds Herbicides Mutations Graphs References Researchers
(Elatine triandra var. pedicellata)

Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)

Japan, Saitama
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.

If we do not have a picture for this weed, or you can provide a better picture (scan, digital camera etc) please please e-mail it to us.

QUIK STATS (last updated Jan 08, 2014 )

Common NameMizohakobe (Waterwort)
SpeciesElatine triandra var. pedicellata
GroupInhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
LocationJapan, Saitama
Contributors - (Alphabetically)Kazuyuki Itoh 
Edit this Case  |  Add New Case of Resistance  |  Add Note


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.

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.
Edit Case  |  Add Note  |  Add Article  |  Add New Case  |  Help


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


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
Literature about Similar Cases

Page size:
Page: of 1
Items 1 to 1 of 1

Page size:
Page: of 1
Items 1 to 1 of 1
PERMISSION MUST BE OBTAINED FIRST if you intend to base a significant portion of a scientific paper on data derived from this site.
Cite this site as: Heap, I.  The International Survey of Herbicide Resistant Weeds.  Online.  Internet.  Monday, May 20, 2024 .  Available
Copyright © 1993- 2024 All rights reserved. Fair use of this material is encouraged. Proper citation is requested.