International Survey of Herbicide-Resistant Weeds

Countries Weeds Herbicides Mutations Graphs References Researchers
GROUP B/2 RESISTANT RICE FLATSEDGE
(Cyperus iria)


ALS inhibitors (B/2)

Brazil, Rio Grande do Sul
INTRODUCTION RICE FLATSEDGE
Rice Flatsedge (Cyperus iria) is a monocot weed in the Cyperaceae family.  In Brazil this weed first evolved resistance to Group B/2 herbicides in 2014 and infests Rice.   Group B/2 herbicides are known as ALS inhibitors (Inhibition of acetolactate synthase ALS (acetohydroxyacid synthase AHAS)).  Research has shown that these particular biotypes are resistant to bispyribac-sodium, imazapic, imazethapyr, penoxsulam, and pyrazosulfuron-ethyl and they may be cross-resistant to other Group B/2 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 Jul 04, 2016 )

Common NameRice Flatsedge
SpeciesCyperus iria
GroupALS inhibitors (B/2)
Herbicidesbispyribac-sodium, imazapic, imazethapyr, penoxsulam, and pyrazosulfuron-ethyl
LocationBrazil, Rio Grande do Sul
Year2014
Situation(s)Rice
Contributors - (Alphabetically)Diego Martins Chiapinotto, and Carlos Eduardo Schaedler 
Edit this Case  |  Add New Case of Resistance  |  Add Note

ACADEMIC ASPECTS

Confirmation Tests

Field, Greenhouse, and Laboratory trials comparing a known susceptible Rice Flatsedge biotype with this Rice Flatsedge 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 Group B/2 resistant Rice Flatsedge 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 B/2 resistant Rice Flatsedge from Brazil please update the database.
 
Edit Case  |  Add Note  |  Add Article  |  Add New Case  |  Help

CONTRIBUTING WEED SCIENTISTS

DIEGO MARTINS CHIAPINOTTO
Undergrad Student - Scholarship Of Scientific Initiation
Universidade Federal do Pampa
Weed Science (Grupo de Herbologia Pampa)
Street Luiz Joaquim de Sá Britto
Itaqui, 97650-000, Rio Grande do Sul
Brazil
Email Diego Martins Chiapinotto
CARLOS EDUARDO SCHAEDLER
Assistant Professor
Universidade Federal do Pampa
Weed Science and Crop (Grupo de Herbologia Pampa)
Promorar
Itaqui, 97650-000, Rio Grande do Sul
Brazil
Email Carlos Eduardo Schaedler

ACKNOWLEDGEMENTS

The Herbicide Resistance Action Committee, The Weed Science Society of America, and weed scientists in Brazil have been instrumental in providing you this information. Particular thanks is given to Diego Martins Chiapinotto, and Carlos Eduardo Schaedler for providing detailed information.
Herbicide Resistant Rice Flatsedge Globally
(Cyperus iria)
Herbicide Resistant Rice Flatsedge Globally
(Cyperus iria)
Drag a column header and drop it here to group by that column
Herbicide Resistant Rice Flatsedge Globally
(Cyperus iria)
#CountryFirstYearSituationActive IngredientsSite of Action
1 BrazilBrazil 2014 Rice bispyribac-sodium, imazapic, imazethapyr, penoxsulam, and pyrazosulfuron-ethyl 5 ALS inhibitors (B/2)
266Cyperus iriaRice Flatsedge13040
2 United States (Arkansas) United StatesArkansas2010 Rice bispyribac-sodium, halosulfuron-methyl, imazamox, imazethapyr, and penoxsulam 45 ALS inhibitors (B/2)
266Cyperus iriaRice Flatsedge5560
3 United States (Louisiana) United StatesLouisiana2013 Rice halosulfuron-methyl 45 ALS inhibitors (B/2)
266Cyperus iriaRice Flatsedge7785
4 VenezuelaVenezuela 2015 Rice pyrazosulfuron-ethyl 80 ALS inhibitors (B/2)
266Cyperus iriaRice Flatsedge11015
Literature about Similar Cases

1
Page size:
select
Page: of 1
Items 1 to 3 of 3

1
Page size:
select
Page: of 1
Items 1 to 3 of 3
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.  Friday, September 22, 2017 .  Available  www.weedscience.org
Copyright © 1993- 2017 WeedScience.org All rights reserved. Fair use of this material is encouraged. Proper citation is requested.