No significant phytotoxic effects were observed for any of the tested compounds, therefore it can be expected that the new antifeedants will not have adverse effects toward the protected seeds. Interestingly, QASs with an amino acid anion and 1-(2-hydroxyethyl)quininium cation caused accelerated growth of white mustard plants compared to the control. As with conventional QASs, the aquatic toxicity of the analyzed quinine derivatives was related to the length of the alkyl substituent in the cation. Despite the lack of clear toxicity of salts with 1-(2hydroxyethyl)quininium and 1-butylquininium cations toward algae (ErC50 > 100 mg dm -3 ), QASs containing a longer alkyl chain were moderately or highly toxic toward C. vulgaris.