Variable rate sprayer. Part 1 – Orchard prototype: design, implementation and validation

Escolà i Agustí, Alexandre; Rosell Polo, Joan Ramon; Planas de Martí, Santiago; Gil Moya, Emilio; Pomar Gomà, Jesús; Camp, Ferran; Llorens Calveras, Jordi; Solanelles Batlle, Francesc

doi:https://doi.org/10.1016/j.compag.2013.02.004

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Issue date

2013

Author

Escolà i Agustí, Alexandre

Rosell Polo, Joan Ramon

Planas de Martí, Santiago

Gil Moya, Emilio

Pomar Gomà, Jesús

Camp, Ferran

Llorens Calveras, Jordi

Solanelles Batlle, Francesc

Suggested citation

Escolà i Agustí, Alexandre; Rosell Polo, Joan Ramon; Planas de Martí, Santiago; Gil Moya, Emilio; Pomar Gomà, Jesús; Camp, Ferran; ... Solanelles Batlle, Francesc. (2013) . Variable rate sprayer. Part 1 – Orchard prototype: design, implementation and validation. Computers and Electronics in Agriculture, 2013, vol. 95, p. 122-135. https://doi.org/10.1016/j.compag.2013.02.004.

Abstract

Discussions in recent decades about dosage models for applying plant protection products in orchards have failed to reach a compromise solution. Furthermore, canopies are spatially variable, and a uniform dose may not be adequate for the entire orchard. Spraying at an adequate volume application rate

on a site-specific basis would help reduce the amount of agrochemicals used in the framework of precision horticulture and precision fructiculture. An orchard sprayer prototype running a variable-rate algorithm to adapt the volume application rate to the canopy volume in orchards on a real-time and continuous basis was designed, implemented, and validated. An equivalent prototype was designed for vineyards and described in a companion paper (‘Variable rate sprayer. Part 2 – Vineyard prototype: Design, implementation and validation’). The orchard prototype was divided into three parts: the canopy characterization system (using a LiDAR sensor), the controller executing a variable-rate algorithm, and the actuators. The controller determines the intended flow rate by using an application coefficient (required liquid volume per unit canopy volume) to convert canopy volume into a flow rate. The sprayed flow rates are adjusted via electromagnetic variable-rate valves. The goal of the prototype was to keep the actual application coefficients as close as possible to the objective. Strong relationships were observed between the intended and the sprayed flow rates (R2 = 0.935) and between the canopy cross-sectional areas and the sprayed flow rates (R2 = 0.926). In addition, when spraying in variable-rate mode, the prototype achieved significantly closer application coefficient values to the objective than those obtained in conventional spraying application mode.

URI

http://hdl.handle.net/10459.1/49470

DOI

https://doi.org/10.1016/j.compag.2013.02.004

Is part of

Computers and Electronics in Agriculture, 2013, vol. 95, p. 122-135