Homogenous and stable adjuvants in the form of microemulsions for use in agriculture containing: a) a mixture of surfactants comprising i) one or more anionic derivatives of an alkylpolyglycoside； ii) one or more alkylpolyglycosides； iii) one or more anionic derivatives of a fatty alcohol； b) one or more methyl esters of fatty acids deriving from the transesterification of vegetable oils, one or more vegetable oils, or mixture thereof； c) one or more nonionic surfactants； d) water.
