Development of a novel precision applicator for spot treatment of granular agrochemical in wild blueberry

Abstract

While spot spraying has gained increasing popularity in recent years, spot application of granule agrochemical has seen little development. Despite the potential for the technology, there currently exists no commercially available granular applicators capable of spot application. Therefore, the goal of this study was to design, build, and lab evaluate a precision applicator for spot applying granular agrochemical in wild blueberry. The design incorporated a John Deere RC2000 with a custom control box, recirculation system, and electrically actuated valves. All components were modified to fit a Valmar 1255 Twin-Roller. The system receives inputs from a predeveloped prescription map and can actuate each of the twelve valves separately to provide individual orifice control. Casoron® G4 was used as the testing agrochemical and in cycling the product pneumatically for 1 hour incurred no significant product degradation (p = 0.110). In lab evaluations, the applicator encountered zero errors in reading prescription maps and actuating the correct valves accordingly. Further, the granule recycling system had zero instances where product built up in the lines or jammed the valves. In all, this project represents the first successful development of a precision granular spot applicator for any cropping system.

Figure 1

Computer aided design (CAD) of pneumatic recirculation system used to assess granule robustness.

Figure 2

Computer aided design (CAD) drawing of the custom valves with the top retaining cover and internal gate removed.

Figure 3

Computer aided design (CAD) drawing of the developed applicator showing both a front (top) and back (bottom) view.

Figure 4

Prototype applicator during lab evaluation.

Figure 5

Prescription map of parking lot at Dalhousie Agricultural Campus, Bible Hill, Nova Scotia, Canada with arbitrarily drawn polygons for lab evaluating the applicators control and actuation systems. The green polygon simulates the non-fescue areas and the orange polygons simulate the fescue areas.