Reservoir Units Optimization in Pneumatic Spray Delivery-Based Fixed Spray System for Large-Scale Commercial Adaptation

Abstract

A pneumatic spray delivery (PSD)-based solid set canopy delivery system (SSCDS) consists of in-line reservoirs and micro-emitter assemblies distributed throughout perennial crop canopies. The existing PSD-based SSCDS uses a large number of reservoirs, i.e., one unit per 3 m of linear spacing, which resulted in high installation and maintenance costs. These reservoirs also produces up to 25% post-spray chemical losses. Therefore, this study aimed to optimize the volumetric capacity and functionality of the existing reservoir for an efficient spray performance and the large-scale commercial adaptation of PSD-based SSCDS. Three reservoirs with volumetric capacities of 370 (1×), 740 (2×), and 1110 mL (3×) were developed to cover a spray span of 3.0, 6.1, and 9.1 m, respectively. Five system configurations with modified reservoirs and spray outlets were evaluated in the laboratory for pressure drop and spray uniformity. The three best system configurations were then field evaluated in a high-density apple orchard. These configurations had reservoirs with 1×, 2×, and 3× volumetric capacity and micro-emitters installed in a three-tier arrangement. Each replicate configuration was installed as a 77 m loop length encompassing 50 apple trees trained in a tall spindle architecture. A pair of water-sensitive paper (WSPs) samplers (25.4 × 25.4 mm) were placed on the abaxial and adaxial leaf surfaces in the bottom, middle, and top third of the canopy to evaluate the spray coverage (%). The PSD-based SSCDS showed no significant difference at the 5% level in terms of coverage among the three reservoir treatments. Coverage was more evenly distributed among the top, middle, and bottom zones for the 2× and 3× as compared to the 1× reservoir treatment. Overall, compared to the 1× reservoirs, the 2× and 3× reservoirs could potentially reduce the system costs by USD 20,000 and USD 23,410 ha−1, respectively, for tall spindle apple orchards and potentially reduce maintenance needs as well.

Fixed Spraying Systems Application in Citrus Orchards: Nozzle Type and Nozzle Position Effects on Droplet Deposition and Pest Control

“…According to characteristics of the citrus canopy structure during the autumn shooting period and their requirements for plant protection, the canopy was divided into three dimensions for sampling, including the horizontal direction, vertical direction, and circumferential direction [23,24].…”

“…Mozzanini et al [22] evaluated the suitability of a hydraulic fixed delivery spray system to be adopted as crop protection technology and found that the emitter flow rate, emitter number, and spray mixture volume injected were the three key factors affecting the dose applied, homogeneity of distribution among emitters, and cleaning performance. Sahni et al [23] investigated the spray effect of a pneumatic spray delivery-based solid set canopy delivery system in a high-density apple orchard, and the results showed that modified reservoirs and a three-tier configuration offered significantly improved zonal coverage uniformity.…”

Pneumatic spray delivery‐based solid set canopy delivery system for oblique banded leaf roller and codling moth control in a high‐density modern apple orchard

“…Our group has extensively researched SSCDS configurations for tall spindle apple architectures typical in WA state. 38,[40][41][42][43][44] PSDbased SSCDS developed by Sinha et al provided improved spray deposition and uniform spray discharge along the spray line compared with hydraulic-based SSCDS 38 . Our latest optimal PSDbased SSCDS provided similar spray deposition, reduced ground drift and negligible aerial drift, but lower spray coverage compared with an airblast sprayer in tall spindle apple orchard.…”

“…Our group has extensively researched SSCDS configurations for tall spindle apple architectures typical in WA state 38,40–44 . PSD‐based SSCDS developed by Sinha et al .…”

“…Our group has extensively researched SSCDS configurations for tall spindle apple architectures typical in WA state. 38 , 40 , 41 , 42 , 43 , 44 PSD‐based SSCDS developed by Sinha et al . provided improved spray deposition and uniform spray discharge along the spray line compared with hydraulic‐based SSCDS 38 .…”