EFFECT OF NOZZLE ORIENTATION ON DISPERSION OF TRUCK MOUNTED ULTRA LOW VOLUME SPRAY AT DIFFERENT HEIGHTS AND DISTANCES

A field evaluation study was conducted to understand the dispersion of spray from a truck-mounted ultra-low-volume (ULV) sprayer when released with the nozzle oriented at the conventional angle of 45° in addition to 22° and 0° with respect to ground surface. The study was conducted in an open grassy field at the Anastasia Mosquito Control District by applying Aqualuer™ 20-20 at the highest label application rate. Mortality of caged female Aedes aegypti was tested at 1.5, 3.0, 6.0, and 8.5 m heights at 0, 30, 60, and 90 m from the spray line. Spray trials were conducted during early morning hours and all test groups were replicated three times over different days. During these evaluations higher mortality was recorded from the 22° and 0° nozzle orientations up to 30 m from the spray line and at heights up to 3 m. The conventional nozzle orientation of 45° provided the greatest mortality 30 m from application source at heights of 6.0 and 8.5 m.