1. Use of substituted fused pyrimidinones and digidropirimidinonov general formula (I) or their soleydlya improve plant tolerance to abiotic stress, where Q represents a group ,, and wherein R, R, R, r and are each has the meaning as defined below, and the dashed line represents communication with a group NR W represents an oxygen or sulfur atom a represents N (nitrogen) or CR group, wherein R b C-R b group each case has the meaning as defined below R, R, R, independently of each other represent hydrogen atom, nitro, am ino, hydroxy, halogen, cyano, alkyl, cycloalkyl, alkenyl, alkynyl, aryl, arylalkyl, arylalkenyl, arylalkynyl, heteroaryl, cycloalkylalkyl, cycloalkylalkenyl, tsikloalkilalkinil, heteroarylalkyl, heteroarylalkenyl, heteroarylalkynyl, haloalkyl, galotsikloalkil, haloalkenyl, galotsikloalkenil, galoalkilalkinil, alkilsililalkinil, alkoxyalkyl, alkoxy, haloalkoxy, alkeniloksialkil, alkylalkoxy, arylalkoxy, alkoxycarbonyl, hydroxycarbonyl, aminocarbonyl, alkylaminocarbonyl, tsikloalkilaminokarbonil, alkylamino, alkenylamino, alkynyl Mino, gidrotio, alkylthio, haloalkylthio, bisalkilamino, cycloalkylamino, alkylcarbonylamino, cycloalkylcarbonylamino, galoalkilkarbonilamino, alkoxycarbonylamino, alkylaminocarbonylamino, alkylsulfonylamino, tsikloalkilsulfonilamino, arylsulfonylamino, getarilsulfonilamino, sulfonilgaloalkilamino, aminoalkilsulfonil, aminogaloalkilsulfonil, alkylsulfonyl, tsikloalkilsulfonil, arylsulfonyl, alkylsulfinyl, tsikloalkilsulfinil, arylsulfinyl, N, S-dialkilsulfonimidoil, S-alkilsulfonimidoil, alkilsulfonilaminokarbon
