用铺展系数和干燥时间来选择草甘膦助剂

Selection of the Proper Surfactants for Glyphosate Ammonium with Spreading Coefficient and Drying time

表面张力是评价制剂性能的重要指标之一。在测试表面张力的基础上,探讨用液滴的铺展系数、干燥时间来选择与草甘膦铵盐相配伍的助剂的可行性。通过测定各单一助剂以及助剂和草甘膦铵盐混配后溶液的表面张力、接触角、铺展直径、干燥时间、有效沉积和生物防效发现,草甘膦铵盐溶液的表面张力越低,接触角越小,铺展得越好,干燥时间越短,沉积越多,防效越好。但是当溶液的表面张力低于30 mN/m时,应该考虑它降低药液沉积的可能性。另外,加入Triton X-100或OP10的草甘膦铵盐溶液防效很好,比Roundup低5%;而加入Tween80后的草甘膦铵盐溶液沉积比Roundup高,但是防效比Roundup低30%。

Surface tension is an important index of pesticide formulation. Based on the surface tension, the spreading coefficient and drying time of droplet were used to choose the proper surfaetants for glyphosate ammonium. The surface tension, contact angle, spreading diameter, drying time, pesticide retention and bio-effieacy of single surfactants and mixtures of glyphosate ammonium with different surfactants were tested. The result showed that the lower the surface tension was;the smaller the contact angle was;and the wider the droplet was spread, the shorter the drying time was;and the more the pesticide deposit was,the better the bio-effieacy was. However, the deposit may be reduced when the surface tension was lower than 30mN/m. In addition, the efficacy of glyphosate ammonium with Triton X- 100 or OP10 was only 5 % less than that of Roundup. Comparatively, the efficacy of glyphosate ammonium with Tween80 was 30% less than that of Roundup, although the deposit of the former was higher than that of the later.