ASHS 2025 Conference

Variable-rate spray technology allows nursery producers to make applications tailored to crops, reducing pesticide application volume and off-target losses. The objective of this study was to evaluate sub-default rates (default=0.1-0.15 L⸱m-3) for the Smart-Apply intelligent spray control system by comparing two intelligent modes with the conventional, constant-rate. We assessed control of powdery mildew (Erysiphe pulchra and Phyllactinia guttata) on ‘Cherokee Princess’ dogwoods (Cornus florida) in a five-row block. A Jacto A400/850 air-blast sprayer with the Smart-Apply system was used to compare: variable-rate: 0.05 L⸱m-3 rate in either pulse-on or pulse-off mode and a reduced, i.e.,