Phenylpyri(mi)dinylazoles of the formula [I-a] and [I-b],
wherein the symbols have the meanings stated in the description, and agrochemically active salts thereof and the use thereof for the control of undesired microorganisms in the protection of plants and materials and for the reduction of mycotoxins in plants and plant parts and methods for the production of compounds of the formula [I-a] and [I-b].