Control Efficiency and Crop Safety of 20% Cyhalofop-butyl WP on Grass Weeds in Direct Seeded Rice Fields

20%氰氟草酯WP对水稻直播田禾本科杂草的防除效果及安全性评价（英文）

The purpose was to define the control efficiency and safety of 20% cy- halofop-butyl WP on grass weeds in direct seeded rice fields, in order to provide the basis for chemical weeding. This study measured Leptochloa chinensis（L.） Nees, Echinoch/oa crusgalli （L.） Beauv and other gramineous weed control efficiency with four concentrations of 20% cyhalofop-dutyl WP and 100 g/L cyhalofop-dutyl EC in direct seeded rice fields, and analyzed the yield-increasing effect and safety of rice. The results showed that 20% cyhalofop-butyl WP had a good control efficiency on grass weeds such as Leptochloa chinensis（L.） Nees, Echinoch/oa crusgalli（L.） Beauv and other grasses. The effective dosage of 90-150 g/hm2 was over 90.7% on Lep- foch/oa chinensis（L.） Nees and the comprehensive control effect of the grass weeds was above 86.7%, which was basically consistent with 100 g/L cyhalofop-dutyl EC. Furthermore, 20% cyhalofop-dutyl WP was high security for direct seeded rice fields. The yield of rice was increased by 10.18%-11.22% after spraying herbicide. There- fore, 20% of cyhalofop-dutyl WP can be used as a special herbicide for controlling Leptochloa chinensis（L.） Beauv in direct seeded rice fields, and has a good applica- tion prospect.

该文旨在研究20%氰氟草酯WP对水稻直播田禾本科杂草的防控效果和应用安全性,为水稻直播田草害的化学防控提供依据。在大田试验中采取4种浓度的20%氰氟草酯WP和100 g/L氰氟草酯EC对水稻直播田千金子、稗草等禾本科杂草的防除效果进行了测定,且对水稻的增产效果和安全性进行了分析。20%氰氟草酯WP对水稻直播田千金子、稗草等禾本科杂草具有良好的防除效果,有效成分用量90~150 g/hm^2对千金子防效在90.7%以上,对禾本科杂草的综合防效均在86.7%以上,与对照药剂100 g/L氰氟草酯EC基本一致。且20%氰氟草酯WP对直播田水稻高度安全,施药后能提高水稻产量,增产幅度为10.18%~11.22%。20%氰氟草酯WP可作为水稻直播田防除千金子的特效药剂,有着良好的应用前景。