International Survey of Herbicide-Resistant Weeds

Countries Weeds Herbicides Mutations Graphs References Researchers
(Ischaemum rugosum)

ACCase inhibitors (A/1)

Saramollagrass (Ischaemum rugosum) is a monocot weed in the Poaceae family.  In Colombia this weed first evolved resistance to Group A/1 herbicides in 2000 and infests Rice.   Group A/1 herbicides are known as ACCase inhibitors (Inhibition of acetyl CoA carboxylase (ACCase)).  Research has shown that these particular biotypes are resistant to fenoxaprop-P-ethyl and they may be cross-resistant to other Group A/1 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 16, 2003 )

Common NameSaramollagrass
SpeciesIschaemum rugosum
GroupACCase inhibitors (A/1)
Contributors - (Alphabetically)Bernal Valverde 
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Confirmation Tests

Greenhouse, and Laboratory trials comparing a known susceptible Saramollagrass biotype with this Saramollagrass 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 Group A/1 resistant Saramollagrass 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 A/1 resistant Saramollagrass from Colombia please update the database.
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Honorary Associate Professor
The University of Copenhagen
Department of Plant and Environmental Sciences
Hojebakkegaard Allé 13
Taastrup, DK-2630, Hovedstaden
Email Bernal Valverde


The Herbicide Resistance Action Committee, The Weed Science Society of America, and weed scientists in Colombia have been instrumental in providing you this information. Particular thanks is given to Bernal Valverde for providing detailed information.
Herbicide Resistant Saramollagrass Globally
(Ischaemum rugosum)
Herbicide Resistant Saramollagrass Globally
(Ischaemum rugosum)
Drag a column header and drop it here to group by that column
Herbicide Resistant Saramollagrass Globally
(Ischaemum rugosum)
#CountryFirstYearSituationActive IngredientsSite of Action
1 ColombiaColombia 2000 Rice fenoxaprop-P-ethyl 10 ACCase inhibitors (A/1)
99Ischaemum rugosumSaramollagrass5143
2 MalaysiaMalaysia 1989 Rubber, and Vegetables paraquat 28 PSI Electron Diverter (D/22)
99Ischaemum rugosumSaramollagrass139
3 VenezuelaVenezuela 2004 Rice bispyribac-sodium, fenoxaprop-P-ethyl, imazapyr, imazethapyr, profoxydim, propanil, and pyribenzoxim 80 Multiple Resistance: 3 Sites of Action
ACCase inhibitors (A/1)
ALS inhibitors (B/2)
PSII inhibitor (Ureas and amides) (C2/7)
99Ischaemum rugosumSaramollagrass5552
Literature about Similar Cases

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Cite this site as: Heap, I.  The International Survey of Herbicide Resistant Weeds.  Online.  Internet.  Friday, March 23, 2018 .  Available
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