Agricultural Spray Dynamics for Automated Pollination of Kiwifruit

Abstract

This research is motivated by a need to efficiently transfer pollen in solution to owers in an orchard where effectiveness of natural wind and been pollination is limited. Specific focus is on kiwifruit and on spraying from a moving robotic platform. A suite of commercial and early-concept nozzles was analyzed and compared, then evaluated based on operating constraints. This was accompanied by experiments conducted in orchards during pollination season, both on the robotic platform and manually. This work also explores the role of spray droplet momentum and kiwifruit blossom properties in pollen solution capture. An analogy is made between blossom anatomy and models for uid capture used in water harvesting applications, which reduce the problem to drops impacting bers/cylinders. The appropriateness of this analogy is made evident through high speed images of drop impacts with blossoms, and by comparing simulations to pollen capture results. A prototype spray nozzle utilizing a novel form of liquid jet perturbation was built and tested. The presented approach resulted in diverse, hitherto unobserved, jet breakup regimes. The system is a new avenue for fundamental uids research in addition to being a useful approach for real-time precision spraying.