Evaluation of Sequences of Certain Insecticide Groups and Biocide Application on Cotton Bollworms, Associated Predators and Cotton Yield in Cotton Fields Egypt

Field experiments were conducted during 2019 and 2020 seasons in Sakh Agricultural Station Farm, Kafr El-Sheikh Governorate, to evaluate the sequences of certain insecticide six groups and biocide on cotton bollworms, associated predators in cotton fields and cotton yield. Sequence of  Ictafos (chlorpyrifos) of organic phosphorus – Topron (chlorofluoezuron) of insect growth inhibitor – Cyperco (cypermethrin) of pyrethroids resulted in the greatest means of reduction (51.07, 71.57 and 83.58%) in number of cotton pink bollworm, pectinophora gossypiella (Saund.), Spiny bollworm, Earias insulana (Boisd.) and American bollworm, Helicoverpa armigera Hubner larvae, respectively. The least means of reduction (25.87, 30.28 and 37.78%) of  number of pink, spiny and American bollworms larvae with sequence of  biocide, (Agrein) only, respectively. All treatments of insecticides were associated with the greatest reduction by range of (65.60 – 69.90%) and (70.34 – 76.14%) on the populations of the six insect predators by the application of  sequences of insecticides and each insecticide alone, respectively. Contrast, sequence of biocide Agrein had the minimum side effect on beneficial predators with mean of reduction (29.05%). The highly effective insecticidal sequence against cotton bollworms had the highly increase in cotton yield production.