International Survey of Herbicide-Resistant Weeds

Countries Weeds Herbicides Mutations Graphs References Researchers
(Raphanus sativus)

ALS inhibitors (B/2)

Radish (Raphanus sativus) is a dicot weed in the Brassicaceae family.  In Brazil this weed first evolved resistance to Group B/2 herbicides in 2001 and infests Wheat.   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 chlorimuron-ethyl, cloransulam-methyl, imazethapyr, metsulfuron-methyl, and nicosulfuron 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 Oct 15, 2003 )

Common NameRadish
SpeciesRaphanus sativus
GroupALS inhibitors (B/2)
Herbicideschlorimuron-ethyl, cloransulam-methyl, imazethapyr, metsulfuron-methyl, and nicosulfuron
Contributors - (Alphabetically)Giovani Theisen 
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Giovani Theisen
Here are some photos of the resistant biotype.
Plant and roots
Plant detail
Plant detail
Plant detail
Root detail
Resistance Trial

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Confirmation Tests

Field, and Greenhouse trials comparing a known susceptible Radish biotype with this Radish 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 B/2 resistant Radish 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 Radish from Brazil please update the database.
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Fundacep Fecotrigo
16650 State Route 536
Cruz Alta, 98100-970, RS
Email Giovani Theisen


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 Giovani Theisen for providing detailed information.
Herbicide Resistant Radish Globally
(Raphanus sativus)
Herbicide Resistant Radish Globally
(Raphanus sativus)
Drag a column header and drop it here to group by that column
Herbicide Resistant Radish Globally
(Raphanus sativus)
#CountryFirstYearSituationActive IngredientsSite of Action
1 ArgentinaArgentina 2008 Canola, Sunflower, and Wheat bispyribac-sodium, chlorimuron-ethyl, diclosulam, flucarbazone-sodium, flumetsulam, imazamox, imazapyr, imazethapyr, iodosulfuron-methyl-sodium, and metsulfuron-methyl 48 ALS inhibitors (B/2)
224Raphanus sativusRadish6738
2 BrazilBrazil 2001 Wheat chlorimuron-ethyl, cloransulam-methyl, imazethapyr, metsulfuron-methyl, and nicosulfuron 5 ALS inhibitors (B/2)
224Raphanus sativusRadish5201
3 ChileChile 2010 Wheat flucarbazone-sodium, imazamox, imazapyr, iodosulfuron-methyl-sodium, metsulfuron-methyl, pyroxsulam, and triasulfuron 8 ALS inhibitors (B/2)
224Raphanus sativusRadish5583
Literature about Similar Cases

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Cite this site as: Heap, I.  The International Survey of Herbicide Resistant Weeds.  Online.  Internet.  Wednesday, March 3, 2021 .  Available
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