Abstract
Bollworms resistance to most registered insecticides has become a major obstacle to their successful chemical control with conventional insecticides. Therefore, field experiments were conducted at Sakha Agricultural Research Station in 2010 and 2011 cotton seasons to study the efficiency of four new mixtures (M) of insecticides, i.e. chloropyrifos + cypermethrin (M1), chloropyrifos + lufenuron (M2), flufenoxuron + alpha-cypermethrin (M3) and thiamethoxam + lambda-cyhalothrin (M4) and two conventional insecticides, chloropyrifos and alphacypermethrin, against cotton bollworms, Pectinophora gossypiella (Saund.) and Earias insulana (Boisd.). Also, their side effects on associated predators were studied. In 2010 season, M3 and alpha-cypermethrin in three successive sprays of each proved to be the superior recording 81.58 and 79.85% reduction in larval infestation, respectively. M4, M1 and chloropyrifos came in the second order without significant differences causing 77.38, 76.65 and 75.27% reduction, respectively. M2 was the least effective with reduction percentage of 74.15. The results of 2011 season showed the same trend of effect for all the tested compounds. According to their side-effects against associated predators, the tested toxicants could be arranged descendingly as follows, alpha-cypermethrin (81.00), M4 (77.96), M3 (76.68), M1 (69.02), M2 (66.07) and chloropyrifos (64.28) % reduction. The obtained results indicated that, the new tested mixtures of insecticides did not exhibit additional advantages in control of the cotton bollworms comparing to the conventional toxicants, where they showed approximately the same effectiveness against the pest and were harmful to the associated predators. Moreover, cross-resistance could be developed after repeated application of these mixtures.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: Alexandria Science Exchange Journal: An International Quarterly Journal of Science Agricultural Environments
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.