Oxazin(ethi)one compounds of the formula I: in which the variables Z, R1, R2, R3 and n are as defined in claim 1 and A is a 5- or 6-membered carbocycle or a 5- or 6-membered heterocycle having 1, 2 or 3 heteroatoms selected from the group consisting of N, O and S, each of which cycles is attached via two carbon atoms to the oxazin(ethi)one ring, and the agriculturally useful salts of the oxazin(ethi)one compounds I are described. Moreover, the invention describes the use of compounds I and their salts for controlling phytopathogenic fungi, compositions which comprise the compounds I and/or their salts in a fungicidally effective amount and a method for controlling phytopathogenic fungi which comprises treating the fungi or the materials, plants, seeds or the soil threatened by fungal attack with a fungicidally effective amount of at least one compound of the formula I as claimed in claim 1 and/or a salt of I.