Determination and Optimization of Operational Factors Affecting Drift in a Smart Spraying System Adapted for Vineyard Conditions

Traditional vineyard spraying often relies on conventional, fixed parameters, leading to significant chemical waste and off-target spray drift, which causes environmental and health risks. Furthermore, there is a lack of optimized operational parameters for viticulture in both practical farming and existing literature.In this study, a smart spraying system (SSS) was revised and adapted for Aegean vineyard conditions. The system was integrated onto a conventional air-assisted orchard sprayer common in the region. The study aimed to determine the optimum parameters for minimizing airborne spray drift during both the pre-flowering and fruit-set periods. Four main factors were tested: forward speed, airflow rate, spray rate, and spray depth. Central Composite Design (CCD) under the Response Surface Methodology (RSM) was used to determine the optimal level of variables. Based on the RSM model, the optimum operational parameters for minimum drift were determined as 4.59 km h⁻¹ forward speed, 33,240 m³ h⁻¹ airflow rate, 0.050 L m⁻³ spray rate, and 1.9 m spray depth for the pre-flowering stage; and 5.97 km h⁻¹, 31,374 m³ h⁻¹, 0.075 L m⁻³, and 1.65 m for the fruit-set stage, respectively. Compared to conventional applications where the smart system was disabled, the optimized smart spraying systems achieved a drift reduction of 92.5% during the pre-flowering period and 89% during the fruit-set period. These findings indicate that integrating smart technologies into existing machinery allows for dynamic parameter management based on phenological canopy structure, providing a sustainable and cost-effective approach to enhancing application efficiency while significantly mitigating environmental risks in precision viticulture.