Synergistic Effect of Nonionic Surfacants（Nonethoxylated Sorbitan Esters） on Herbicides in Paddy Fields

An uneven herbicide distribution can lead to reduced efficacy, and the release of herbicide residues and their transformation products into the environment through runoff increases their potential use risk. Understanding the water distribution dynamics of commonly used paddy field herbicides, for example, oxadiazon, is imperative for the long-term management of weeds in paddy fields. To clarify the diffusion and sedimentation ability of oxadiazon with the addition of a nonionic surfactant—diffusion and settling agent（DSA） for subsequent commercial use in paddy field water layers, the synergistic mechanisms of DSA with butachlor and bensulfuron-methyl in paddy fields were studied. Bioassays, instrumental analysis and field experiments were conducted in this research to provide a relevant basis for improving the efficacy of paddy field herbicides. The field experiment results indicated that DSA could increase the plant and fresh weight control effects of oxadiazon（450 g a.i. · hm-2）, butachlor and bensulfuron-methyl to different degrees. These findings demonstrated that DSA could not only effectively improve oxadiazon diffusion and settling in water layers and significantly increase the control effects of butachlor and bensulfuron-methyl, but also promote crop growth and development to different degrees.