Management of two-spotted spider mite (Tetranychidae: Tetranychus urticae Koch) on potato (Solanum tuberosum L.) in Eastern Hararghe, Ethiopia

Abstract

AbstractThe potato is an important tuberous vegetable crop. However, its production and values are constrained by various factors, including the two-spotted spider mite (TSSM) in East Hararghe, Ethiopia. An investigation of the TSSM management by the application of botanicals and synthetic insecticides was conducted in the laboratory and greenhouse. The experiment was arranged in CRD. The treatment was replicated four times in the greenhouse and five times in the laboratory. The efficacy and LC50 bioassays of Amitraz, Profenofos, and Emamectin benzoate, as well as the oils of Azadirachta indica seed and Tagetes minuta leaf, and their leaf aqueous extracts, were tested in the laboratory at three dose levels. Similarly, Amitraz, Profenofos, Emamectin benzoate (EB) and extracted oils of Azadirachta indica seed alone and in combination were tested in a greenhouse The data was collected after 24, 48, and 72 hours of their application in the laboratory. And in the greenhouse, within 7, 14, and 21 days before and after application. In the laboratory, the highest mortality of TSSM adults was recorded with EB at 80 µL (74–97%), followed by profenofos at 35 µL (71–90%). Among the botanicals, the A. indica seed oil at 5% caused the highest mortality of TSSM adults (72–100%). Amitraz also caused the highest mortality of TSSM eggs (72.5–92.5%), and it required in 100ml of tap water to kill 50% of the eggs. T. minuta leaf oil had higher toxic effects on TSSM eggs (0.239%). In the greenhouse, the dose combination of Amitraz, EB, and profenofos caused higher mortality of TSSM than their sole application.

Keywords

• Assessment
• botanicals
• chemical pesticide
• median lethal concentrations
• LC50
• management