Effect of Tank-Mix Adjuvants on the Efficiency of Chlorpyrifos and Cyhalothrin Formulations against Cotton Bollworms

Abstract

Reduction infestation percentages of spiny bollworm (SBW), Earias insulana (Boisd.),and pink bollworm (PBW), Pectinophora gossypiella (Saund.),on cotton treated with some chlorpyrifos and cyhalothrin formulations alone or/and mixed with Top Film or Tritone K adjuvants were investigated under field conditions. Adjuvants/insecticides mixtures enhanced the reduction percentages of E. insulana infestation, compared with individually applied insecticides. Mixtures of Top Film with chlorpyrifos or cyhalothrin formulations gave the highest reduction percentages of infestation, where general reduction average ranged between 81% and 89.7%, and between 86.5% and 93.2%, respectively. Moreover, Tritone K mixed with cyhalothrin formulations displayed adequate infestation reduction, as general reduction averages ranged between 80.6% and 88.1%. In general, tank mixing of both adjuvants with cyhalothrin formulations enhanced the efficiency of formulation greater than mixing adjuvants with chlorpyrifos formulations against E. insulana. On the other hand, the infestation percent of P. gossypiella was lower than that of E. insulana in untreated cotton plants. The formulations alone or their mixtures with adjuvants gave good reduction of infestation, where the general reduction averages ranged between 88% and 93.5%, and between 70.6% and 87.1% for formulations/adjuvants mixtures and formulations alone, respectively.