PACE Pesticide dose adjustment for orchards

1. Set farm reference sprayer

• As a once only exercise, establish the farm reference sprayer settings: air-flow, forward speed and nozzles (flow rate, type, number and position).
• The farm reference sprayer should be set for the selected fruit (i.e. standard orchard where efficient use is made of the spraying product when it is applied at the recommended label dose rate). The pome fruit standard is an orchard with a tree-height of 3m, row-spacing of 3.5m and std branch-density. Some farms may not have an orchard of this specification, however, it is still recommended that the standard is used to establish the farm reference sprayer settings even if these are hypothetical.
• Select the type, number and position of the nozzles to give appropriate adjustment of spray height and water volume application rate across the full range of target orchards.
• The practice of making air-flow adjustment to different orchards is not widespread amongst fruit growers in the UK. Ideally, the air-flow should be adjusted to obtain spray plume penetration of the tree-row on either side of the sprayer, without producing excessive spray beyond this target. If the spray plume does not produced sufficient penetration of the tree-row this may increase deposit variation, reduce treatment efficacy and it may be necessary to compensate the applied dose.
• Acceptable work rates can be achieved with a forward speed of 6.5 kmph (4 mph) for typical spraying conditions in the UK.
• If possible avoid making excessive variation of forward speed as this can cause variation of spray plume height, canopy penetration and deposit.