Cleaning Performance Evaluation of Pneumatic Spray Delivery Based Solid Set Canopy Delivery System

Solid set canopy delivery system (SSCDS), a fixed spray system variant, has the potential to realize automated and timely spray applications in modern grapevine production systems typical of Washington State in the United States. Optimized SSCDS configurations could be a viable replacement for conventional pesticide application equipment (PAE) and can also help with abiotic stress management. However, SSCDS, as a PAE, should effectively mitigate the risks and environmental impacts associated with pesticide use. This study was thus aimed at evaluating a pneumatic spray delivery (PSD)-SSCDS, first in the laboratory and then under field conditions, to understand system cleaning performance according to a methodology based on the ISO22368-1 (2004) standard for such fixed and semi-mobile sprayers. The cleaning performance was quantified as the percent amount of residue in the SSCDS components after the spray application. A pilot laboratory setup was used to evaluate the PSD-SSCDS component cleaning performance. The system was cleaned using five viable cleaning techniques: air injection for 30 (conventional cleaning technique), 60, 90, and 300 s, and one water rinse after 30 s air injection. The technique that performed best was field evaluated in a large-scale modern grapevine layout. Overall, the use of water to rinse the system component achieved cleaning performance >99.67%. Field trials also demonstrated that the PSD-SSCDS layout was easy to clean through a triple water rinse and capable of meeting the ISO16119-4 (2014) set threshold.