Decoupled precision variable rate spray system for orchards improves deposition and drift

Constant-rate spraying in orchards results in non-uniform spray deposition, whereas variable-rate spray systems can improve spray deposition uniformity and minimise drift. Improved deposition uniformity and reduced drift enhance crop management efficiency. Variable and constant rate spraying were compared via a series of trials in an apple orchard during one season using a prototype decoupled precision variable rate spray system. Spray deposition, drift, and biological efficacy of an insecticide were measured and compared between constant and variable rate sprays. The variable spray system significantly reduced deposition variance and spray drift compared to the constant rate. Biological efficacy remained similar between the two spray methods.