Compounds of 3- (3,4-dihydro-2H-benzo [1,4] oxazin-6-yl) -1H-pyrimidine-2,4-dione as herbicides

Uracils of formula I wherein R1 is hydrogen or halogen; R2 is hydrogen, C1-C6 alkyl, C1-C6 haloalkyl, C3-C6, C3-C6 haloalkenyl, C3-C6, alquiniloC3-C6 haloalkynyl C3-C6 alkyl, C1-C6 alkyl or C3-C6-C1 C6 alkyl; R3 is hydrogen or halogen; R4 is halogen; R5 is hydrogen, NH2, C1-C6 alkynyl or C3-C6 alkyl; R6 is hydrogen, C1-C6 haloalkyl or C1-C6 alkyl; R7 is hydrogen or C1-C6 alkyl; X is O or S; and Y is O or S; including their agriculturally acceptable salts.