Developing a pesticide spraying machine suitable for grape orchards

Abstract This paper aimed to develop and evaluate a sprayer tailored for grape trellis systems in Egyptian orchards. The developed sprayer was assessed at three forward speeds (2.4, 3.4, and 4.6 km h −1 ), two types of spray nozzle types (flat-fan and hollow-cone), and two nozzle-to-leaf distances (40 and 60 cm), and three operating pressures (10, 15, and 20 bar). The results showed that the highest droplet density (197 droplets/cm 2 ) was achieved with flat-fan nozzles at an operating pressure of 20 bar and a forward speed of 2.4 km h −1 . In contrast, the lowest droplet density (73 droplets/cm 2 ) occurred at the highest forward speed of 4.6 km h −1 . Furthermore, the mean droplet diameter decreased with increasing pressure; the smallest overall was 170 μm with the hollow-cone nozzle at an operating pressure of 20 bar and a forward speed of 4.6 km h −1 . The maximum field capacity of 3.32 fed/h was recorded with a flat-fan nozzle, 10 bar pressure, and a forward speed of 4.6 km h −1 .