Dinitrogen trifluoride or nitrous oxide and / or its useful salts in agriculture and their use to control plant pathogens is a method of controlling harmful plant pathogens, including the treatment of fungi or plants, soil or seeds to protect them from chemical attack, with an effective amount of There is at least one compound of formula (1) or nitrous oxide or an acceptable salt in agriculture； at least including the agrochemical composition of one compound and the agrochemical composition containing seeds. 1. Property 1: compound (1) with formula property,The acceptable positive oxides or their salts in agriculture are as follows: A is phenyl, or the heteroaromatic cycle of 5 or 6 members, in which, in addition to carbon atoms, the heteroaromatic cyclic atoms also include 1, 2, 3 or 4 heteroatoms selected from n, or s as a cyclic atom； and The phenyl ring or aromatic ring is not replaced or replaced by 1, 2, 3 or 4 identical or different RA groups； RA is halogen, cyanogen, no832222；Oh, SH, nh832222,a. 6-6-6-6-6-6-6-6-6-6-6-6-6-6-6-7-7-7-7-7-7-7-e； Three or four r74919 are the same or different, among which r74919 is halogen, cyanogen and no832222；Oh, SH, nh832222,C₁₋₆-alkyl, C₁₋₆-haloalkyl, C₁₋₆-alkoxy, C₁₋₆-haloalkoxy, C₁₋₆-alkylthio, C₁₋₆-haloalkylthio or C₃₋₈-cycloalkyl or C₁₋₄-alkoxy-C₁₋ ₄-alkyl； L is - (C = O) -,- (C 3DS) - o -S (3DO) -The shattering or smell of three to ten members, In addition to the carbon atom, the ring atom with single or double ring period includes the extra heteromorphic atom 1, 2, 3 or 4 selected from n, or s as the ring atom, The heterocyclic ring composed of one or two carbon atoms can be replaced by one or two selected groups independent of C (= O) and C (= s)；and wherein the heteroaryl group in heteroaryl-C₁₋₄-alkyl is a 5- or 6-membered aromatic heterocycle, wherein the heterocyclic ring member atoms include, in addition to carbon atoms, 1, 2, 3 or 4 heteroatoms selected from N, O, and S as ring member atoms； and wherein any of t
