Pyrazoles of the formula I where: R1 is hydrogen, nitro, halogen, cyano, thiocyanato or an aliphatic radical; R2 is a substituted sulfur, nitrogen or phosphorus atom; R3 is hydrogen, halogen or an aliphatic radical; R4, R5 are hydrogen, nitro, halogen, cyano, thiocyanato, or an aliphatic radical; R6 is hydrogen, halogen, C1-C6-alkyl, C1-C6-alkoxy, C3-C8-cycloalkyl; R7, R8, R9 are hydrogen, C1-C6-alkyl, but at most one of the radicals R7, R8 and R9 is hydrogen; and their tautomers and agriculturally useful salts are described. Moreover, the invention relates to processes for preparing compounds of the formula I, to compositions comprising them and to the use of the compounds of the formula I and of the compositions comprising them for controlling harmful plants.