PMC9445492_01
Location of the study area and test fields. Field 1 represents the test field of the unmanned aerial vehicle and ground machine spraying method; Field 2 represents the test field of the conventional artificial method.
fpls-13-959429-g001.jpg
PMC9445492_01_fpls-13-959429-g001.jpg
fig1
A pear (Pyrus bretschneideri) orchard was selected as the target study area, which was located in Pinggu district, Beijing (Figure 1).
Major pesticide application equipment used in the study, including unmanned aircraft vehicles (A-C), unmanned ground vehicles (D) and conventional manual spray guns (E).
fpls-13-959429-g002.jpg
PMC9445492_01_fpls-13-959429-g002.jpg
fig2
Five orchard pesticide application equipment were adapted in the study, including three mainstream orchard unmanned aircraft vehicles, one unmanned ground vehicle and one conventional manual spray gun (Figure 2).
Layout of the test (A) and sample point (B). The yellow line represents the flight route of the UAV; the blue line represents the route of UGVs and humans; the red triangle represents the sample trees; and the black rectangle represents the sample point.
fpls-13-959429-g003.jpg
PMC9445492_01_fpls-13-959429-g003.jpg
fig3
Five consecutive trees were sampled in the middle row of each test field, and sample trees were no less than 10 m from the beginning and end of the row to ensure that the equipment was working stably when passing through (Figure 3A). The number of sample points set in the upper, middle and lower layers was 4, 5 and 8, respectively (Figure 3B).
Layout of the sample site in the test of ground residue (A), human body residue (B) and machine residue (C). The red circle represents the sample point.
fpls-13-959429-g004.jpg
PMC9445492_01_fpls-13-959429-g004.jpg
fig4
For the ground residue test, white art papers were attached to the ground at the center of rows and trees (Figure 4A). For the machine residue test, white art papers were randomly attached around the equipment, including the rotor, arm, tank, and shell (Figure 4C). For the human body residue test, white art papers were randomly pasted on the head, arm, chest and leg (Figure 4B).