FIELD: agriculture.SUBSTANCE: invention relates to agriculture. Nematicidal agent contains as an active substance at least one compound of formula (I): (I) where B is a 2-pyridyl, 3-pyridyl or 4-pyridyl, X is selected from a group comprising halogen, C1-C8-alkyl, C1-C8-haloalkyl, having from 1 to 5 halogen atoms, C1-C8-alkoxy, n equals 1 or 2 and if n equals 2, then substitutes X may be identical or different, R1 and R2 are identical or different and are selected from a group, including hydrogen, halogen, cyano, C1-C6-alkyl, C2-C6-alkenyl, C2-C6-alkynyl, di-(C1-C6-alkyl)amino, C1-C6-alkoxy, C3-C6-cycloalkyl-C1-C6-alkyl, C1-C6-alkoxycarbonyl, -OC(O)-C1-C6-alkyl, 2,6-dichlorophenyl-carbonylamino, 2-chlorophenyl-carbonylamino and phenyl, or R1 and R2 together with carbon atom to which they are bonded, form a 3- or 5-member carbocycle, R3 and R4 are identical or different and are selected from a group comprising hydrogen, -COOH, C1-C6-alkyl, C1-C6-alkoxy, hydroxy-C1-C6-alkyl, C1-C6-alkoxy-C1-C6-alkyl, C1-C6-haloalkyl having from 1 to 5 halogen atoms, -CONH(C1-C6-alkyl), C1-C6-alkoxycarbonyl, -OC(O)-C1-C6-alkyl and phenyl R5 is selected from a group comprising hydrogen, C3-C7-cycloalkyl C1-C6-alkylcarbonyl A is a phenyl group of formula (A1): (A1) where R is selected from a group comprising halogen, nitro, -OH, cyano, C1-C8-alkyl, C1-C8-haloalkyl having from 1 to 5 halogen atoms, C1-C8-alkoxy, -NH(C1-C8-alkyl), phenyl (optionally substituted C1-C6-alkoxy), or two R, bonded with adjacent carbon atoms, together represent -O(CH2)pO-, where p equals 1, m equals 0, 1 or 2 and if m is equal to 2, then substitutes R may be identical or different provided that when B is 2-pyridyl, then at least one of R1, R2, R3, R4 and R5 is a hydrogen atom, and R2 and R3 may also together with carbon atoms with which they are bonded, form a 3-, 6- or 7-member carbocycle, provided that when B is 4-pyridyl, then R2 and R3 may also together with carbon atoms with which they are bonded form a 6-
