International Survey of Herbicide-Resistant Weeds

Countries Weeds Herbicides Mutations Graphs References Researchers
(Leptochloa chinensis)

PSII inhibitor (Ureas and amides) (C2/7)

Malaysia, Kelantan
Chinese Sprangletop (Leptochloa chinensis) is a monocot weed in the Poaceae family.  In Malaysia this weed first evolved resistance to Group C2/7 herbicides in 2006 and infests Rice.   Group C2/7 herbicides are known as PSII inhibitor (Ureas and amides) (Inhibition of photosynthesis at photosystem II).  Research has shown that these particular biotypes are resistant to propanil and they may be cross-resistant to other Group C2/7 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 20, 2015 )

Common NameChinese Sprangletop
SpeciesLeptochloa chinensis
GroupPSII inhibitor (Ureas and amides) (C2/7)
LocationMalaysia, Kelantan
Contributors - (Alphabetically)Chuah Tse-Seng 
Edit this Case  |  Add New Case of Resistance  |  Add Note



Chuah Tse-Seng
Chuah TS, Hartini M, Adzemi MA, Ismail BS (2006b) Propanil resistance of Leptochloa chinensis growing at paddy fields in Kelantan. Malaysian Applied Biology 35, 1–5

Edit this Note  |  Add New Note

Chuah Tse-Seng

 B. SAHID, JULIANA KARSO, TSE-SENG CHUAH, 2011. Resistance mechanism of Leptochloa chinensis Nees to propanil. Weed Biology and Management, vol. 11, no. 2, pp. 57-63 

The resistance mechanism of Leptochloa chinensis Nees to propanil was investigated, based on propanil metabolism, aryl acylamidase activity, and chlorophyll fluorescence at the 8 week growth stage of L. chinensis.The concentration of propanil in the leaf and culm extracts of the resistant (R) and susceptible (S) biotypes, as measured by gas chromatography (GC),was found to increase after propanil treatment.The concentration of propanil in the leaf and culm extracts of the S biotype at 72 h was 1.55 and 0.49 mg mL-1, respectively. However, a lower concentration of propanil was observed in the R biotype, as compared to that in the S biotype. The residue of 3,4-dichloroaniline, as measured by GC, was detected only in the leaf extracts of the R biotype. In contrast, no residue of 3,4-dichloroaniline was observed in the S biotype. The level of aryl acylamidase in the leaf tissue extracts of the R biotype was ~140% higher than that in the S biotype. The fluorescence studies showed that propanil inhibited the quantum efficiency of the photosystem II in both the R and S biotypes after 2 h of incubation time. However, when the leaf disks were transferred and incubated in deionized water for 48 h, the quantum efficiency increased in the R biotype but decreased in the S biotype. These results suggest that propanil metabolism, enhanced by aryl acylamidase activity, is the most likely factor contributing towards the mechanism of propanil resistance in L. chinensis plants at the 8 week growth stage.

Edit this Note  |  Add New Note


Confirmation Tests

Greenhouse, and Laboratory trials comparing a known susceptible Chinese Sprangletop biotype with this Chinese Sprangletop 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 C2/7 resistant Chinese Sprangletop 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 C2/7 resistant Chinese Sprangletop from Malaysia please update the database.
Edit Case  |  Add Note  |  Add Article  |  Add New Case  |  Help


Universiti Malaysia Terengganu
Department Of Agrotechnology
Faculty Of Agrotechnology & Food Science
Kuala Terengganu, 21030, Terengganu
Email Chuah Tse-Seng


The Herbicide Resistance Action Committee, The Weed Science Society of America, and weed scientists in Malaysia have been instrumental in providing you this information. Particular thanks is given to Chuah Tse-Seng for providing detailed information.
Herbicide Resistant Chinese Sprangletop Globally
(Leptochloa chinensis)
Herbicide Resistant Chinese Sprangletop Globally
(Leptochloa chinensis)
Drag a column header and drop it here to group by that column
Herbicide Resistant Chinese Sprangletop Globally
(Leptochloa chinensis)
#CountryFirstYearSituationActive IngredientsSite of Action
1 ChinaChina 2011 Rice cyhalofop-butyl 9 ACCase inhibitors (A/1)
223Leptochloa chinensisChinese Sprangletop5671
2 MalaysiaMalaysia 2006 Rice propanil 28 PSII inhibitor (Ureas and amides) (C2/7)
223Leptochloa chinensisChinese Sprangletop10948
3 South KoreaSouth Korea 2012 Rice cyhalofop-butyl, fenoxaprop-P-ethyl, and metamifop 27 ACCase inhibitors (A/1)
223Leptochloa chinensisChinese Sprangletop7855
4 ThailandThailand 2002 Rice fenoxaprop-P-ethyl, profoxydim, and quizalofop-P-ethyl 47 ACCase inhibitors (A/1)
223Leptochloa chinensisChinese Sprangletop5199
Literature about Similar Cases

Page size:
Page: of 2
Items 1 to 5 of 6

Page size:
Page: of 2
Items 1 to 5 of 6
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, January 25, 2021 .  Available
Copyright © 1993- 2021 All rights reserved. Fair use of this material is encouraged. Proper citation is requested.