The invention relates to novel effective alkinyl-substituted 3-phenylpyrrolidine-2,4-diones according to the general formula (I) or agrochemically acceptable salts thereof,(I) wherein X = C1-C4 alkyl, C1-C4 haloalkyl or C3-C6 cycloalkyl, Y = C1-C4 alkyl or C3- C6 cycloalkyl, R1 = hydrogen, C1-C6 alkyl, or C3-C6 cycloalkyl, R2 = hydrogen or methyl, R3 = C1-C6 alkyl or C1-C6 alkoxy-C2- C6alkyl, G = hydrogen, a group L that can be split or a cation E, wherein R3 is not methyl, if R1 = methyl and R3 is not C1-C3 alkyl, R1 = H. The invention further relates to a herbicide composition containing a compound of the general formula (I) and to the use of the compounds according to the invention for combating weeds and weed grasses in useful plant crops.
