The Effect of Various Adjuvants on the Systemic Insecticidal Activity of Phorate and Zectran

Eighty-seven adjuvants were screened for their influence on the systemic insecticidal activity of phorate and Zectran®, 4-dimcthylaminino-3,5-xylyl methylcarbamate. The insecticides, at 100 ppm, and the adjuvants, at 50 ppm, were added to plant nutrient solutions in which cotton seedlings were placed. Boll weevils, Anthonomus grandis Boheman, were confined on the plants for 48 hr. The mortality of boll weevils plants in insecticide plus adjuvant was compared with that on plants exposed to Zectran alone. None of the adjuvants affected the activity of phorate; however, 3 significantly enhanced the systemic activity of Zectran. All 3 were quaternary ammonium chlorides and the only chemicals of this type included in the tests. No synergistic effect was involved and the adjuvants were either affecting the roots or the insecticide in such a manner that the insecticidal activity of Zectran was increased.