The present invention relates to novel effective alkynyl-substituted 3-phenylpyrrolidine-2,4-diones according to the general formula (I) or agrochemically acceptable salts thereof, where X = C1-C4-alkyl, C1-C4-haloalkyl or C3-C6-cycloalkyl； Y = C1-C4-alkyl or C3-C6-cycloalkyl； n = 1, 2 or 3； m = 1 or 2； R1 = C1-C6-alkyl, or C3-C6-cycloalkyl； R2 = hydrogen or methyl； R3 = C1-C3-alkoxy-C1-C3-alkyl, or a saturated five- or six-membered heterocycle with an oxygen or sulphur atom； G = hydrogen, a cleavable group L or a cation E.The invention also relates to the use of the compounds according to the invention for controlling weeds and weed grasses in crops of useful plants.本發明係關於新穎有效之根據通式(I)的經炔基取代之3-苯基吡咯啶-2,4-二酮或其農化上可接受的鹽，其中X=C1-C4-烷基，C1-C4-鹵烷基或C3-C6-環烷基；Y=C1-C4-烷基或C3-C6-環烷基；n=1,2或3；m=1或2；R1=C1-C6-烷基，或C3-C6-環烷基；R2=氫或甲基；R3=C1-C3-烷氧基-C1-C3-烷基，或帶有氧或硫原子的五元或六元雜環；G=氫、一個可切斷的基團L或陽離子E。本發明亦關於根據本發明的化合物用於防治雜草和有用的植株作物中之雜草之用途。
