In 2016 and 2017 was inducted field experiment by “Block method” at the Maize Research Institute, Knezha, R Bulgaria. The subject of the research was the local hybrid Kn 509 (FAO 500 group of maturity), grown under non-irrigating conditions, after the wheat crop. 7 herbicide systems have been obtained only in vegetation period. The most efficient herbicide combinations are: Calaris Pro (2 l/ha) + Milagro (0.2 kg/dka) with 87% killed weeds, Elumis (2 l/ha) + Pik (0.02 kg/ha) with 84% killed weeds and self-introduced leaf herbicide Principal +“ at a dose 0.4 kg/ha with 86% destroyed weeds. Biological efficacy of the herbicides is linked with grain yield.The highest grain yield of maize (6060 t/ha) has been obtained from the self-introduced variant with Principal + at a dose of 0.4 kg/ha.