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ARS Home » Midwest Area » Wooster, Ohio » Application Technology Research » Research » Research Project #434568

Research Project: Investigation of Laser-guided Variable-rate Spray Technology in Washington State Apple Orchards

Location: Application Technology Research

Project Number: 5082-21620-001-013-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Jul 1, 2018
End Date: Jun 30, 2023

The objectives of this research are to compare pesticide application effectiveness of conventional orchard sprayers retrofitted with the laser-guided variable-rate spray system at different growth stages with respect to: spray deposition uniformity inside canopies; spray drift losses to the ground and in the air; biological efficacy in the control of pests and diseases commonly occurred in northwestern state apple orchards; chemical usage and cost per acre; and labor costs.

To demonstrate that the new laser-guided variable-rate spray system will reliably and effectively control pests with significant reductions in pesticide consumption and spray application costs, a standard axial fan airblast sprayer, similar to the ones used by grower’s, will be upgraded with ARS' new intelligent spray control system. Field tests with randomized complete block designs consisting of paired plots with replications for the sprayers using intelligent control system and the same sprayers with the conventional constant-rate mode will be conducted to compare 1) spray deposition efficiency and uniformity inside canopies, 2) spray drift losses to the ground and in the air, 3) spray volume usage, 4) associated labor costs at different growth stages, and 5) reliability/use of the system. Artificial targets and fluorescent tracers will be used to simulate leaves to collect spray and assess canopy deposition and drift. A flow meter and rate controller will be installed to measure spray volume used. Labor and chemical costs associated with spraying more or less in an acreage will be calculated based on standard WA wages and average chemical costs for an insecticide. Reliability and durability of the new spray system will be qualitatively evaluated by documenting spray hours and lessons learned with the sprayers for possible future improvement of the technology as applied in apple orchards. At least one field day will be scheduled during which growers will be able to witness operation of the technology and provide feedback. Research findings will be disseminated through direct interactions with growers through field demonstration events, websites, state and regional fruit meetings, newsletters, and trade shows.