Insecticides and Their Mixtures for Controlling Tuta Absoluta Infesting Tomato under Egyptian Field Conditions
El-Sayed H.Tayeb , Abd EL-Fattah A. Saad and Mahmoud. A. Elbialy
Field trials were carried at El-Ashartalaf feddan region, Behaira government, Egypt during two successive seasons of 2016 and 20117 to evaluate four insecticides and three of their mixtures against the tomato leafminer Tuta absoluta under field conditions. The seven evaluated insecticidal treatments were applied in three consequent sprays within an interval of 10 days between each in addition to the treatment of untreated check. The lonely or individually evaluated insecticides included chlorantraniliprole, thiamethoxam, lufenuron and chlorpyriphos which have been sprayed according to the recommendations of the Egyptian Ministry of Agriculture. Meanwhile, their evaluated mixtures: chlorantraniliprole + thiamethoxam, chlorantraniliprole+ lufenuron and thiamethoxam + lufenuronwere were applied at the rate of half recommended dose of each insecticide within the tested mixture. The obtained results showed a more or less toxic efficiency of the individually and/or admixed insecticides against the insect throughout both the seasons of 2016 and 2017. In the first season of 2016, the mixture of chlorantraniliprole + lufenuron was comparatively high effective during the elapsed period after the 1st and 2nd spray; furthermore it was proved to be the utmost superior efficient post the 3rd spray achieving complete infestation reduction (100%) of larvae. During the second season of 2017, chlorpyriphos was the most effective tested individual insecticide. The mixture of chlorantraniliprole + lufenuron was proved again to be superior achieving reduction level of 100% after the 3rd spray. Therefore, this mixture would be recommended for achieving efficient control of T. absoluta in the growing tomato plants under field conditions. It is also better to use chlorpyriphos alone in IPM program to reduce the costs and slow down the development of resistance of this insect-pest to other involved compounds in the mixtures.
Keywords: Tomato plants, the tomato leafminer Tuta absoluta, insecticidal treatments, mixture of insecticides and infestation reduction percentage.