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Resistance of dicot weeds to acetolactate synthase (ALS)‐inhibiting herbicides in Australia
Author(s) -
BOUTSALIS P.,
POWLES S. B.
Publication year - 1995
Publication title -
weed research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.693
H-Index - 74
eISSN - 1365-3180
pISSN - 0043-1737
DOI - 10.1111/j.1365-3180.1995.tb02028.x
Subject(s) - acetolactate synthase , imazapyr , sulfonylurea , mcpa , biology , herbicide resistance , agronomy , weed , botany , weed control , microbiology and biotechnology , enzyme , biochemistry , insulin
Summary A biotype of Sonchus oleraceus L. and two bio types of Sisymbrium orientate Torn., SSO 3 and NSO 1, are the first dicot weeds in Australia to develop resistance to ALS‐inhibiting herbicides. The resistant biotypes had been exposed to va rying periods of selection with sulfonylurea her bicides. All three biotypes are resistant to a range of sulfonylurea and imidazolinone herbicides. The S. orientale biotypes are also resistant to the triazolopyrimidine herbicide, flumetsulam. LD 50 ratios of resistant Sonchus oleraceus for sulfony lurea and imidazolinone herbicides are greater than 64‐fold and 4.5‐fold, respectively. GR 50 ratios are greater than 9 for sulfonylureas and 7.4 for imazapyr. The LD 50 ratios for both S. orien tale biotypes for chlorsulfuron, sulfometuron methyl, metsulfuron‐methyl, flumetsulam and imazethapyr are greater than 110‐, 15‐, 7‐, 24‐ and 29‐fold, respectively. All resistant biotypes are susceptible to MCPA, diuron and diflufenican, herbicides which do not inhibit ALS.