Wind field and droplet coverage characteristics of air‐assisted sprayer in mango‐tree canopies

Abstract

BACKGROUND Air‐assisted sprayers is one of the primary fruit tree pest control approaches in agricultural production. It is necessary to study the influence of multiple factors on both wind field and droplet coverage of air‐assisted sprayers. In this article, foliage area volume density (FAVD) and power gradient were considered factors, and field tests were conducted in an orchard to determine such influence. RESULTS The results showed that in‐canopy wind speed was mainly affected by the air‐assisted sprayer. FAVD showed significance to the wind speed and droplet coverage inside canopies (P < 0.001), compared with power gradient (P > 0.05). With the increase of FAVD, the wind speed in the bottom layer of canopies first increased and then decreased, while the wind speed in the middle and top layers first decreased and then increased. Meanwhile, the wind field was mainly concentrated on the surface of canopies and gradually approached the canopy center as the power gradient increased. Furthermore, a Back‐Propagation (BP) neural network prediction model was constructed to predict droplet coverage at any canopy location to avoid repeated experiments. The overall correlation coefficient (R) of this model was about 0.731, indicating good fitting performance. CONCLUSION FAVD has a significant effect on wind speed and droplet deposition inside the canopy, and the air‐assisted sprayer parameter setting should consider the effect of FAVD. The prediction model can predict droplet deposition inside the canopy without repeating. The study can provide a reference for selecting operating parameters of air‐assisted sprayers and help reduce droplet loss and environmental pollution. © 2022 Society of Chemical Industry.

Factors Affecting Droplet Loss behind Canopies with Air-Assisted Sprayers Used for Fruit Trees

“…For the five fruit trees, the loss behind the canopy, as expressed as droplet coverage on WSPs, was lower at P1 and P2. According to the authors' previous research [29], the From Figure 4, it can be seen that:…”

“…For the five fruit trees, the loss behind the canopy, as expressed as droplet coverage on WSPs, was lower at P1 and P2. According to the authors' previous research [29], the droplet coverage within the canopy could meet the spray requirements when power gradients were P1 and P2. Therefore, P1 or P2 could be preferred for fruit tree spraying to reduce the droplet coverage behind canopies.…”

Design and experimental assessment of a field‐spraying system with nozzles employing reciprocating up‐and‐down movements

“…Air‐assisted spraying uses an auxiliary airflow to deliver pesticides to the crop 4–6 . Air‐assisted boom sprayers are extensively used in this field.…”

“…[1][2][3] Air-assisted spraying uses an auxiliary airflow to deliver pesticides to the crop. [4][5][6] Air-assisted boom sprayers are extensively used in this field. The penetration and deposition of droplets are increased, and the environmental risk due to spray drift phenomenon is reduced.…”

Stereoscopic plant-protection system integrating UAVs and autonomous ground sprayers for orchards

“…Meanwhile, the droplet distribution of the air-assisted sprayer was non-uniform in the top layers and was better in the bottom layers. ( Chen et al., 2020 ; Jiang et al., 2022 ). These pre-test results were highly consistent with the issue on the basis of the literature review above.…”