predkl\u00e1dan\u00e9 solve the concerns pouzit\u00ed substances of general formula cu.sub.2.n.so.sub.3.n..mso.sub.3.n..2h.sub.2.n.o where m is cu, mn or fe, to protect plants from fungal onemocnen\u00edmi. furthermore, concerns the way of plant protection of fungal onemocnen\u00edmi pesticidn\u00edho product containing at least one substance and that of the general formula.