Pyridazine compounds of formula I'.A, the salts thereof, the N-oxides thereof and the salts of the N-oxides thereof, where the radical A is selected from the radicals of the formulae A-1, A-2, A-3, A-4, A-5 and A-6: wherein: # denotes the point of attachment to the remainder of formula I'.A, and wherein R A1, R A5 are independently of each other selected from hydrogen, halogen, C 1 -C 4 -alkyl, C 1 -C 4 -haloalkyl, C 1 -C 4 -alkoxy, C 1 -C 4 -haloalkoxy, C 1 -C 3 -alkylen-CN, C 1 -C 3 -alkylen-OR a, C 3 -C 7 -cycloalkyl, C 3 -C 7 -cycloalkyl-C 1 -C 3 -alkyl, and 3- to 7-membered saturated heterocyclyl-C 1 -C 3 -alkyl, wherein cycloalkyl and heterocyclyl in the 3 last mentioned radicals may be unsubstituted or may carry 1, 2, 3, 4 or 5 identical or different substituents R y; R A2, R A4 are independently of each other selected from hydrogen, halogen, C 1 -C 4 -alkyl, C 1 -C 4 -haloalkyl, C 1 -C 4 -alkoxy, C 1 -C 4 -haloalkoxy, C 1 -C 3 -alkylen-CN, C 1 -C 3 -alkylen-OR a, C 3 -C 7 -cycloalkyl, C 3 -C 7 -cycloalkyl-C 1 -C 3 -alkyl, and 3- to 7-membered saturated heterocyclyl-C 1 -C 3 -alkyl, wherein cycloalkyl and heterocyclyl in the 3 last mentioned radicals may be unsubstituted or may carry 1, 2, 3, 4 or 5 identical or different substituents R y; R A3 is selected from hydrogen, halogen, C 1 -C 4 -alkyl, C 1 -C 4 -haloalkyl, C 1 -C 4 -alkoxy, C 1 -C 4 -haloalkoxy, C 1 -C 3 -alkylen-CN, C 1 -C 3 -alkylen-ORa, C 3 -C 7 -cycloalkyl, C 3 -C 7 -cycloalkyl-C 1 -C 3 -alkyl, and 3- to 7-membered saturated heterocyclyl-C 1 -C 3 -alkyl, wherein cycloalkyl and heterocyclyl in the 3 last mentioned radicals may be unsubstituted or may carry 1, 2, 3, 4 or 5 identical or different substituents R y; R 1 is selected from hydrogen, C 1 -C 3 -alkyl, C 1 -C 3 -haloalkyl and C 1 -C 3 -alkoxy-C 1 -C 3 -alkyl; R a is selected from hydrogen, C 1 -C 4 -alkyl, C 1 -C 4 -haloalkyl and C 1 -C 4 -alkoxy-C 1 -C 2 -alkyl; R y is selected from halogen, nitro, C 1 -C 4 -alkyl, C 1 -C 4 -haloalkyl, C 1 -C 4 -alkoxy, C 1 -C 4 -haloalkoxy, C 1 -C 4 -alkylsulfonyl and C 1 -C 4 -haloalkylsulfonyl; except for the compounds of the formula I'.A, wherein R 1 is hydrogen and A is selected from the group consisting of 2,6-difluoro-4-pyridyl, 2,6-dichloro-4-pyridyl, 2,6-dibromo-4-pyridyl and 2,6-diiodo-4-pyridyl. R A1, R A5 are independently of each other selected from hydrogen, halogen, C 1 -C 4 -alkyl, C 1 -C 4 -haloalkyl, C 1 -C 4 -alkoxy, C 1 -C 4 -haloalkoxy, C 1 -C 3 -alkylen-CN, C 1 -C 3 -alkylen-OR a, C 3 -C 7 -cycloalkyl, C 3 -C 7 -cycloalkyl-C 1 -C 3 -alkyl, and 3- to 7-membered saturated heterocyclyl-C 1 -C 3 -alkyl, wherein cycloalkyl and heterocyclyl in the 3 last mentioned radicals may be unsubstituted or may carry 1, 2, 3, 4 or 5 identical or different substituents R y; R A2, R A4 are independently of each other selected from hydrogen, halogen, C 1 -C 4 -alkyl, C 1 -C 4 -haloalkyl, C 1 -C 4 -alkoxy, C 1 -C 4 -haloalkoxy, C 1 -C 3 -alkylen-CN, C 1 -C 3 -alkylen-OR a, C 3 -C 7 -cycloalkyl, C 3 -C 7 -cycloalkyl-C 1 -C 3 -alkyl, and 3- to 7-membered saturated heterocyclyl-C 1 -C 3 -alkyl, wherein cycloalkyl and heterocyclyl in the 3 last mentioned radicals may be unsubstituted or may carry 1, 2, 3, 4 or 5 identical or different substituents R y; R A3 is selected from hydrogen, halogen, C 1 -C 4 -alkyl, C 1 -C 4 -haloalkyl, C 1 -C 4 -alkoxy, C 1 -C 4 -haloalkoxy, C 1 -C 3 -alkylen-CN, C 1 -C 3 -alkylen-ORa, C 3 -C 7 -cycloalkyl, C 3 -C 7 -cycloalkyl-C 1 -C 3 -alkyl, and 3- to 7-membered saturated heterocyclyl-C 1 -C 3 -alkyl, wherein cycloalkyl and heterocyclyl in the 3 last mentioned radicals may be unsubstituted or may carry 1, 2, 3, 4 or 5 identical or different substituents R y; R 1 is selected from hydrogen, C 1 -C 3 -alkyl, C 1 -C 3 -haloalkyl and C 1 -C 3 -alkoxy-C 1 -C 3 -alkyl; R a is selected from hydrogen, C 1 -C 4 -alkyl, C 1 -C 4 -haloalkyl and C 1 -C 4 -alkoxy-C 1 -C 2 -alkyl; R y is selected from halogen, nitro, C 1 -C 4 -alkyl, C 1 -C 4 -haloalkyl, C 1 -C 4 -alkoxy, C 1 -C 4 -haloalkoxy, C 1 -C 4 -alkylsulfonyl and C 1 -C 4 -haloalkylsulfonyl;