Ethoxylated rapeseed oil derivatives as novel adjuvants for herbicides.
Ethoxylates of rapeseed oil and of methylated rapeseed oil were synthesized and tested as adjuvants for 2,4-D and phenmedipham. Provided they had less than 6 units of ethylene oxide (EO), 1.0 to 10 g litre(-1) ethoxylates in water induced droplet spreading on barley leaves. In an acetone-based medium all derivatives strongly promoted the foliar uptake of 2,4-D, with no clear influence of the ethoxylation degree. In the same medium there was a negative influence of ethoxylate chain length on the foliar uptake of phenmedipham. In a water-based medium, phenmedipham applied with rapeseed oil emulsified with ethoxylated (20 EO) rapeseed oil displayed uptake rates close to a commercial preparation. The same was true for phenmedipham applied with ethoxylated (2 EO) methylated rapeseed oil. In bioassays, phenmedipham prepared with methylated rapeseed oil emulsified with ethoxylated (20 EO) rapeseed oil was as efficacious on barley as a commercial formulation. The same was true for phenmedipham prepared with ethoxylated (2 EO) methylated rapeseed oil. However, neither rapeseed oil nor methylated rapeseed oil emulsified with ethoxylated (2 EO) methylated rapeseed oil conferred good efficacy to phenmedipham. Hence, ethoxylated rapeseed oil derivatives are promising adjuvants or formulants for herbicides.
Müller
Thomas
T
Laboratoire de Phytopharmacie, INRA BP 86510, 21065 Dijon Cedex, France.
Brancq
Bernard
B
Milius
Alain
A
Okori
Nathalie
N
Vaille
Claude
C
Gauvrit
Christian
C
D015084:2,4-Dichlorophenoxyacetic Acid / Q000633:toxicity; D001681:Biological Assay; D002219:Carbamates / Q000633:toxicity; D002250:Carbon Radioisotopes; D005027:Ethylene Oxide / Q000737:chemistry / Q000494:pharmacology*; D005229:Fatty Acids, Monounsaturated; D006540:Herbicides / Q000633:toxicity*; D001467:Hordeum / Q000187:drug effects / Q000254:growth & development; D010574:Pesticide Synergists / Q000737:chemistry / Q000494:pharmacology*; D010938:Plant Oils / Q000737:chemistry / Q000494:pharmacology*; D000074262:Rapeseed Oil; D013501:Surface-Active Agents / Q000737:chemistry / Q000494:pharmacology*
D002219:Carbamates; D002250:Carbon Radioisotopes; D005229:Fatty Acids, Monounsaturated; D006540:Herbicides; D010574:Pesticide Synergists; D010938:Plant Oils; D000074262:Rapeseed Oil; D013501:Surface-Active Agents; D015084:2,4-Dichlorophenoxyacetic Acid; D005027:Ethylene Oxide; C100128:phenmedipham