Air-assisted sprayer airflow interaction with traditional olive orchard canopies and its effect on spray distribution

Vigo-Morancho, Alba (Universidad de Zaragoza) ; Videgain, María (Universidad de Zaragoza) ; Serreta, Alfredo (Universidad de Zaragoza) ; Boné, Antonio (Universidad de Zaragoza) ; Vidal, Mariano (Universidad de Zaragoza) ; García-Ramos, Francisco Javier (Universidad de Zaragoza)

Resumen: Air-assisted sprayers currently incorporate mechanisms that allow modification of airflow outlet characteristics, which is a key factor in product distribution quality. However, limited information exists on how airflow interacts with complex tree canopies, particularly in traditional olive orchards. The aim of this study was to model the behavior of airflow velocity generated by a previously laboratory characterized air assisted sprayer in a traditional olive orchard, as a function of air flow configuration (fan gearbox) and operational and canopy structural parameters.
Five olive trees were selected, and a three-dimensional grid of 64 measurement points (4 depths × 4 sections × 4 heights) was defined, where airflow velocity (m s−1) was recorded with a vane probe anemometer under two sprayer configurations. Canopy characterization was carried out using Light Detection and Ranging (LiDAR) measurements, from which both canopy volume (m3) and density based on the number of impacts (NI) at each sampling location were determined. In addition, manual defoliations of 0.008 m3 cubes were performed at 8 positions per canopy, allowing a correlation between impacts and leaf area density (LAD, m2 m−3) to be established (R2 = 0.61).
Airflow within the canopy was characterized, and a model including sprayer gear setting, measurement depth, height, and categorized vegetation density (low or high density, LD or HD, respectively, based on the accumulated number of impacts across trees, NIa) explained 72% of the observed variability in air velocity inside the tree canopy. Spray performance was evaluated at the same sampling points using water-sensitive papers (WSP) and tracer collectors (manganese, Mn), allowing the effects of application parameters on coverage (%) and deposition (µg cm−2) to be quantified. These effects were largely consistent with those influencing air velocity, which was strongly correlated with both coverage and deposition. Notably, adequate coverage and deposition levels were predominantly associated with air velocities inside the canopy exceeding 2 m s−1, providing valuable insight for optimizing sprayer adjustment and operating conditions.

Idioma: Inglés

DOI: 10.1016/j.compag.2026.111587

Año: 2026

Publicado en: Computers and Electronics in Agriculture 246 (2026), 111587 [13 pp.]
ISSN: 0168-1699

Financiación: info:eu-repo/grantAgreement/ES/MICINN/PDC2022-133395-C43
Financiación: info:eu-repo/grantAgreement/ES/MICINN/PID2019-104289RB-C43

Tipo y forma: Article (Published version)

Área (Departamento): Area Ingeniería Agroforestal (Dpto. CC.Agrar.y Medio Natural)
Área (Departamento): Área Ingeniería Mecánica (Dpto. Ingeniería Mecánica)
Área (Departamento): Área Expresión Gráfica en Ing. (Dpto. Ingeniería Diseño Fabri.)