Re-envisioning agrichemical input delivery: Solid Set Delivery Systems for high density fruit production. Impacts on off-targetdeposition

摘要

Solid Set Canopy Delivery Systems (SSCDS) are a novel method of insecticide spray application that consist of a network of permanently plumbed irrigation micro-sprayers positioned in high density orchard canopies. SSCDS are mounted to orchard trellissystems and are optimized around the delivery of inputs to narrow canopies (<2m). A prototype SSCDS developed at Michigan State University has provided pest management results comparable to that achieved using traditional radial airblast sprayers, whilealso offering benefits of virtually eliminated applicator exposure, expanded range of conditions in which applications can be made, and the potential to be fully automated. This study was the first attempt to characterize and compare spray drift betweenthese two application systems. Vertical and horizontal spray drift characteristics of the prototype SSCDS were measured and compared to a canopy-optimized radial fan air blast sprayer. Verticalflux using 1.8 mm braided polypropylene string and qualitative deposition using water sensing paper was measured to 8 m height and horizontal downwind deposition was measured quantitatively using Mylar targets spaced 2, 4, 8, 16 and 64 m downwind of the treated row. Both vertical and horizontal drift profiles showed a nearly two order of magnitude reduction for the SSCDS compared to the air blast sprayer. The majority of vertical and horizontal spray drift for the SSCDS was constrained to below 4 meters and within 8 meters downwind, respectively. In contrast, theair blast sprayer produced detectable drift at the maximum height and vertical distances measured (8 m and 64 m, respectively).