FIELD: agriculture. SUBSTANCE: substitutes of 3,5-dioxo-3,4,5,6-tetrahydrooxazines, formula I where R1, R3-C1-C4 - alkyl, R2 = hydrogen or C1-C4 - alkyl; R4 - hydrogen; R - halogen, trifluoromethyl, R5 - hydrogen, halogen, C1-C4 - alkyl or C1-C4 - alkoxy, substituted by 1-3 atoms of halogen, SC1-C4 - alkyl, SO2-C1-C4 - alkyl or OSO2-C1-C4 - alkyl and treatment of weeds or their dissemination centers with compound of formula I in the amount of 0.05-11 kg/ha. Structure of compound of formula I 
. EFFECT: higher efficiency. 5 cl, 2 tbl
