"The majority of high density apple orchards are treated with axial fan radial air blast sprayers, which can result in large off target agrochemical losses since they were designed to spray larger canopies. Solid set canopy delivery systems (SSCDS) offer an alternative style of spray application, with microsprayers placed within the tree canopy for foliar applications. Limited research exists on the spray characteristics and pest management efficacy of this novel technology. My thesis research was to quantify the surface coverage, chemical deposition, and season long pest management of a SSCDS in a high density apple orchard. Coverage evaluations using water sensitive paper show that the SSCDS obtains higher levels of coverage on the adaxial leaf surface than on the abaxial surface. Additionally, SSCDS display similar levels of adaxial coverage to an air blast, but lower abaxial coverage than an air blast. Deposition evaluations with tartrazine dye show that despite the difference in coverage profiles, SSCDS treated plots showed higher levels of dye recovery, indicating more chemical was retained on leaf surfaces. Pest management evaluations in 2013, 2014, and 2016 showed little difference in levels of pest and pathogen damage in both treatments, while untreated areas displayed high levels of damage. Preliminary results suggest that both systems have similar management efficacy, while an SSCDS has the potential to offer additional benefits over air blast sprayers."--Page ii.
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