Spray application – notes

September 2009 | Future Orchards® Orchard Walk notes | Spray application and calibration

These notes explain practical orchard spray calibration and the move toward distance-based dosing. They include conversion approaches for litres per 100 metres, litres per hectare and litres per tree, allowing growers to compare different calibration systems and relate application rate to canopy and row geometry.

The resource draws on experience from viticulture, where distance-based calibration, optimised sprayer setup and coverage assessment improved disease control while reducing spray volume, spraying time and off-target losses. One example cited in the notes reports powdery mildew incidence falling from around 10-15 per cent to 1-3 per cent after a coordinated spray-application program was implemented.

For orchard growers, the practical lesson is that calibration is not just a compliance exercise. It can improve coverage, reduce drift and soil contamination, increase work rate and lower costs. The notes encourage growers to become comfortable with row-length based calculations and to judge sprayer setup against actual target coverage.