The invention relates to an organic ammonium salt of formula (I), wherein the symbols have the following meanings: A- is an anionic pesticide, R1 is H, C1C4-alkyl, CH2CH2OH or CH2CH(CH3)OH； R is H, CH3 or two adjacent radicals R together form a group —C(R′)— and R′ is equal to or different from H or CH3, wherein said salt is suitable for reducing the volatility of active substances in the spray application of anionic pesticides.
