摘要 |
The present invention relates to a synergistic agent containing a herbicidally active sulphonylurea of the formula I <IMAGE> in which Z represents a substituted phenyl, thiophenyl, benzyl, pyridinyl, pyrazinyl, hetero-fused phenyl, or alkylsulphonylamino radical; M represents hydrogen; or C1-C4-alkyl; and Het represents a substituted five- or six-membered heterocycle having 2 or three nitrogen atoms, and a synergistically active amount of a 5,6,7,8-tetrahydro-1H,3H- (1,3,4)thiadiazolo-[3,4-a]-pyridazine or 7,8-dihydro-1H,3H- (1,3,4)-thiadiazolo-[3,4-a]-pyridazine of the formula II <IMAGE> in which X represents oxygen; or sulphur; A-B represents -CH2-CH2-; or -CH=CH-; and Phe represents a substituted phenyl radical. The agent according to the invention is suitable for selective control of weeds in crops of useful plants, in particular in cereals, maize, rice or soybeans. The invention also relates to a method of controlling weeds in crops of useful plants, preferably in cereals, maize, rice or soybeans, and to the use of this novel agent. |