Influence of Adjuvants on the Surface Tension, Deposition and Effectiveness of Herbicides on Fleabane Plants

ABSTRACT: The use of herbicides is widespread in weed management, and adjuvants are added to the spray solution to improve the effectiveness of applications. The goal was to evaluate the influence of adjuvants added to the herbicides saflufenacil and glyphosate, isolated or in combination, and the effects on the surface tension, deposition and effectiveness in post-emergence applications to control Conyza sumatrensis. Experiments were conducted completely randomized experimental design to evaluate surface tension (TS), deposition and herbicide effectiveness. The treatments were glyphosate, glyphosate + saflufenacil and saflufenacil with or without the adjuvants Natur’al óleo®, Assist®, Aterbane®, Sillwet L-77 and Dash HC® (surface tension). For the experiments about mixture deposition and herbicide effectiveness, the factorial scheme 3 x 5 was adopted in the experiment performed in April, where factor A corresponded to the combination of the herbicieds glyphosate, saflufenacil and glyphosate + saflufenacil, and factor B was the addition of the adjuvants Natur’al óleo®, Assist®, Aterbane®, Sillwet L-77. For experiments conducted in November, the adjuvant Dash HC® was added, and the 3x6 factorial design was adopted. The adjuvants reduced the ST of the herbicide mixture, and Silwet L-77® was the most effective one. However, the ST reduction did not influence the mixture deposition on C. sumatrensis plants. The use of adjuvants did not result in an effective control for the applications with sole glyphosate.

摘要：除草剂在杂草防控中应用广泛，助剂常被添加至喷雾药液中以提升施药效果。本研究旨在评价助剂单独或复配添加至氯氟草醚乙酯（saflufenacil）与草甘膦（glyphosate）中的影响，及其对苗后施药防控苏门白酒草（Conyza sumatrensis）时的表面张力（surface tension，缩写ST）、药液沉积与防控效果的作用。试验采用完全随机试验设计，以评估表面张力（ST）、药液沉积及除草剂防控效果。试验处理包括：单剂草甘膦、草甘膦+氯氟草醚乙酯复配剂，以及分别添加或不添加Natur’al óleo®、Assist®、Aterbane®、Sillwet L-77与Dash HC®的氯氟草醚乙酯单剂（用于表面张力相关试验）。针对药液沉积与除草剂防控效果的试验采用3×5因子设计，于4月开展：因子A为除草剂组合（草甘膦单剂、氯氟草醚乙酯单剂、草甘膦+氯氟草醚乙酯复配剂），因子B为添加的助剂种类（Natur’al óleo®、Assist®、Aterbane®、Sillwet L-77）。11月开展的试验新增助剂Dash HC®，采用3×6因子设计。研究发现，助剂可降低除草剂复配药液的表面张力，其中Silwet L-77®的降张效果最为显著。但表面张力的降低并未影响药液在苏门白酒草植株上的沉积量。单独施用草甘膦时，添加助剂未实现有效的杂草防控效果。