Abstract
A standard PTO-driven air-blast sprayer was used to investigate the effect of air volume on spray penetration and deposition in citrus applications. Air volume and velocity were varied using interchangeable fans on the sprayer. For each fan size, applications were made at different spray volume rates. Spray penetration was determined by deposition of a fluorescent tracer on cotton ribbons within the entire canopy depth and the deposition was determined by fluorimetry. Air volume had a significant effect on mean deposition but spray volume did not. The interaction between air volume and spray volume was significant. Overall, the results suggest that high air volume rates may not give significant increase in spray deposition or canopy penetration. It appears that the air and spray penetration largely depend on tree canopy structure and prevailing wind direction.
