Dual-fan Orchard Sprayer with Reversed Air-stream - Preliminary Trials

The dual-fan concept was developed to spray on high trees (up to 5 meters). The aim of the preliminary trials was to evaluate the idea of a dual-fan orchard sprayer before producing sprayer prototype. After laboratory measurements of spray and air distribution the measurements of air distribution, spray distribution and spray drift potential were made in the apple orchard. Four fan settings were studied. Spray volumes applied (150÷400 l/ha) caused significantly different spray deposits in the tree canopy. The highest deposit was observed for the lower fan alone. The coverage on lower surfaces for “Lower+Upper+30cm” fan was higher than for the other combinations. Total losses were proportional to deposits in the trees.