Evaluation of Insecticides for Management of Emerging Two Spotted Spider Mite, Tetranychus urticae Koch (Acari: tetranychidae) on Tomato In Grusum District, Somali Regional State, Eastern Ethiopia

Abstract

Two spotted spider mite(TSSM)a world pests feed on numerous cultivated and wild plants. It is important emerging tomato infesting pest in eastern Ethiopia. There is scarce information on recommended insecticicides for the managements of TSSM on tomato. The efficacy of five insecticides viz., Radiant 120 SC, Torque 550 SC, Profit 72 EC, Agro-Thoate 40% EC and Selecron 720 EC along with control were evaluated against TSSM in Gursum district of Somali Regional State. Two round applications were made at different interval in Randomized Complete Block Design replicated three times. Mean mite at pre-spray, after four (3, 6, 9 and 14) post spray, mite percent reduction, infestation and tomato fruit yield were used for effectiveness of tested insecticides.  Cost-effectiveness of insecticides determined bases on yield and control costs. The study revealed that all insecticides reduced mite population significantly   than control plots. The differences between tested insecticides in percent mite reduction during both 1???????? and 2???????? round application were not significant. Percent mite infestation found lower in all insecticides treated plants. The highest yield 335.93 qt, and highest yield gain over control 144.67 qt was obtained from profit. All insecticides sprayed plots gave the highest gross income and net income than the untreated plots. Among tested insecticides Profit 72 EC sprayed plot provided the highest gross income (839,825) and maximum net income 355,575 Ethiopian Birr (ETB). The lowest gross income 478,150 ETB obtained from untreated plots. The highest benefit cost ratio 1:84 obtained from Radiant. Based on the study four insecticides viz., Radiant 120 SC, Profit 72 EC, Agro-Thoate 40% EC and Selecron 720 EC found cost-effective and recommended for the management of the two spotted spider mite on tomato. These insecticides registered to be used in vegetable insect pest control.