Spray Application – Factors to Consider

Selection of the nozzle is the most critical factor in all spray application.

Craig Day from Spray Safe and Save discusses the factors to consider to ensure safe spray application at the Eyre Peninsula Agricultural Research Foundation (EPARF) members day held at the Minnipa Agricultural Centre. Inversion layers are the biggest risk factor for spray drift in Australia.

Nozzles must operate within their correct pressure range. This is affected by ground speed, terrain, the size of the spray rig and the size of the tractor towing the rig.

Nozzle Operation and Pressure Range

Factors to consider in the spray application process or for any grower no matter where they are, is the selection of the nozzle. Now, we’re looking at nozzle selection now. We have to look at spray quality to meet the new requirements that are appearing on some labels. So, when selecting a nozzle, it must be operated within it’s correct pressure range.

That’s gonna be effected by your ground speed, your terrain, the size of your rig, the size of your tractor. These factors all have to come into these decisions. An applicator is really forced at the moment by time constraints. Weather conditions and the suitability of those conditions is a major important factor to be considered when going and doing an application.

Risk of Inversion Layers

Inversion layers are probably our biggest risk area for the incidents of drift in Australia. And historically, when we looked at the introduction of recording issues for weather, we’ve concentrated too heavily just on Delta-T. The concentration of a Delta-T factor, in fact you and I are only looking at that in isolation is very dangerous from an applicator’s point of view.

And that concentration at a high delta T has forced people with the ability of GPS technology to spray in more inversions [xx] conditions which is creating most of the issues that we see.