Bioactivity and efficacy evaluation of 17 herbicides on Veronica persica in winter wheat fields

To screen high-efficiency herbicides for the control of V. persica, the activity of 17 post-emergence herbicides against V. persica in wheat fields was determined using a whole plant dose response experiment. The toxicity and field evaluated efficacy was examined for ten herbicides selected with high activity. The results have shown that at the recommended dosage, the 10 herbicides including triclopyr-butotyl, diflufenican, fluroxypyr, tribenuron-methyl, MPCA-sodium, pyroxsulam, isoproturon, amidosulfuron, bromoxynil octanoate, and bixlozone have higher activity. The inhibition rate of the fresh weight was 89.10%～95.18%. Diflufenican, pyroxsulam, and bromoxynil octanoate had high toxicity for V. persica, and GR₉₀ was 89.28, 6.52, and 155.42 g·hm⁻², which were all below the recommended dose of dim dimidius. The second was carfentrazone-ethyl, bipyrazone, mesosulfuron-methyl, and thifensulfuron-methyl and the inhibition rate of the fresh weight was 76.60%～87.63%. Flucarbazone-Na and flumetsulam had poor fluoride activity and Florasulam had no use value. Field efficacy testing showed that 216 g·hm⁻² of bixlozone and 15 g·hm⁻² of pyroxsulam had the highest control effect on V. persica after 120 days, with a fresh weight control effect of between 97.11% and 95.59%. The second was 1 260 g·hm⁻² of MPCA-sodium, 262.5 g·hm⁻² of diflufenican and 22.50 g·hm⁻² of fluroxypyr, with a fresh weight control effect of between 84.06% and 90.39%. These five herbicides can effectively control V. persica at the recommended dose.