Optimal efficacy of the essential nozzle characteristics and insecticide type for controlling cabbage aphid

The previous works have addressed selecting the nozzle to minimize the hazard of pesticide drift by producing large spray droplet sizes. However, this spray application with the largest sizes does not effectively impact insects either, as it needs many pesticides. Several studies have demonstrated that the small spray droplet sizes can affect the insects and be obtained by selecting the appropriate nozzle size and height. This study sheds light on the nozzle sizes and heights, and insecticide types for controlling the cabbage aphid to ensure efficient insect control. Different parameters including three sizes of flat fan nozzle 01, 02, and 03, two nozzle heights 35 and 70 cm above the plant top, and two insecticide types 20% wide plus WP and 90% methomyl SP were investigated to measure spray deposition, coverage percentage, and droplets density in different locations of the cabbage plant for improving control efficacy. The outcomes showed significant differences in the spray deposition and coverage percentage using different nozzle sizes, nozzle heights, and insecticide types. The best spray deposition, coverage percentage, and control efficacy (0.321 µm.cm-2, 15.05%, and 84.83%, respectively) were achieved using the 02 nozzle size, nozzle height of 35 cm methomyl SP insecticide type on the fourteenth day after spraying application in comparison to the others. The fourteenth day was the most effective to control aphids compared to the first and the seventh days.