The invention relates to N-cyclopropyl-2-oxopyrrolidine-3-carboxamide derivatives and related compounds of general formula (I) as herbicidal plant protection agents, in particular for controlling weeds and/or weed grasses in crops of useful plants and/or as plant growth regulators for influencing the growth of crops of useful plants. The invention further relates to herbicidal and/or plant growth-regulating agents comprising one or more of the compounds of formula (I).