Leaf blight disease (LBD) caused by Pantoea agglomerans is a newly emerged oat disease in China that causes great economic and yield losses of oat production. Laboratory and field experiments were conducted to evaluate the efficacy of 13 antimicrobial agents against P. agglomerans and recommend agents with better control efficacy for use. The antibacterial potential of four concentrations of each agent was evaluated under in vitro conditions. Zhongshengmycin and ethylicin were the most effective in inhibiting the growth of P. agglomerans; their bacteriostatic rates (85.0% and 84.8%, respectively) were higher while EC₅₀ lower (0.31 and 0.90, respectively) than other agents. The greenhouse and field experiment suggested that the greatest fresh weight per plant (57.26 g and 57.93 g), forage yield (22.53 t/ha and 22.21 t/ha) and control efficacy (>75%) were obtained after spraying twice with zhongshengmycin or ethylicin in the LBD occurrence phase, with lower yields and control by kasugamycin + dicopper chloride trihydroxide, kasugamycin + oxine copper, benziothiazolinone, copper hydroxide, phenanthrenecarboxylicacid, copper, picoxystrobin, chloroisobromine cyanuric acid, oxathiapiprolin or azoxystrobin. Foliar application of zhongshengmycin or ethylicin can therefore be used for the effective management of LBD of oat.