Abstract
The objective of this study was to develop an autonomous spraying system with high deposition performance for large-scale melon greenhouses. A spraying robot with low-concentration, high-volume electrostatic spraying nozzle was tested. The robot was equipped with a total of eight electrostatic spraying nozzles with a per-nozzle discharge rate of 0.56L/min and charge to mass ratio of −0.45mC/kg. The robot could apply pesticide stably without operators by being guided by magnetic tape on the greenhouse floor. The deposition indexes of electrostatic spraying on the backside and underside of water-sensitive paper placed in front of the melon community were 8.0-10, and were two-fold higher than those of non-electrostatic spraying. At the back of the melon community, deposition indexes for the electrostatic method were significantly higher than those for the non-electrostatic method. When the application rate was increased from 100 to 300L/10a, the deposition index of electrostatic method became higher. There was no significant difference in the insect pests control effect between the robot and conventional manually spraying method. In the field test, the effective field capacity of the robot was 3.8a/h at the application rate of 450L/10a.
