University of Würzburg , Julius von Sachs Institute of Biosciences , Julius-von-Sachs-Platz 3 , Würzburg D-97082 , Germany.
Syngenta Crop Protection, Global Formulation Technology , Breitenloh 5 , Münchwilen CH-4333 , Switzerland.
J Agric Food Chem. 2018 Jun 13;66(23):5770-5777. doi: 10.1021/acs.jafc.8b01102. Epub 2018 Jun 4.
We comprehensively studied the complexity of the mode of action of adjuvants by uncoupling the parameters contributing to the spray process during foliar application of agrochemicals. The ethoxylated sorbitan esters Tween 20 and Tween 80 improved the efficiency of pinoxaden (PXD) in controlling grass-weed species in greenhouse experiments by aiding retention, having humectant properties, maintaining the bioavailability, and increasing the cuticular penetration of PXD. The nonethoxylated sorbitan esters Span 20 and Span 80 showed minimal effects on retention, droplet hydration, or cuticular penetration, resulting in reduced PXD effects in the greenhouse. Tris(2-ethylhexyl)phosphate (TEHP) does not contribute much to retention and spreading but strongly enhances the diffusion of PXD across isolated P. laurocerasus cuticular membranes. As TEHP was most efficient in controlling the growth of grass-weed species, we propose that the direct effect of penetration aids on cuticular permeation plays a key role in the efficiency of foliar-applied agrochemicals.
我们通过解耦在农用化学品叶面施用过程中对喷雾过程有贡献的参数，全面研究了助剂作用模式的复杂性。乙氧基化山梨糖醇酯吐温 20 和吐温 80 通过帮助保持滞留、具有保湿特性、维持生物利用度以及增加吡氟酰草胺（PXD）的角质层穿透性，提高了吡氟酰草胺在温室实验中控制阔叶草的效率。非乙氧基化山梨糖醇酯司盘 20 和司盘 80 对滞留、液滴水合或角质层穿透性的影响最小，导致温室中 PXD 的效果降低。三（2-乙基己基）磷酸酯（TEHP）对滞留和扩展的贡献不大，但能强烈促进 PXD 在分离的桃金娘科叶片角质层膜中的扩散。由于 TEHP 在控制阔叶草生长方面最为有效，因此我们提出，渗透助剂对角质层渗透的直接作用在叶面施用农用化学品的效率中起着关键作用。
