Spraying Large Nut Trees – Part 2

This article continues from Part 1. Droplet size Droplet size influences droplet behaviour. The following table lists the pros and cons to changing droplet size when overall spray volume (e.g. L/ha) remains constant. Learn more about droplet behaviour here. It is preferred to use nozzles that create coarser droplets at higher rates (to compensate for […]

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Spraying Large Nut Trees – Part 1

Introduction I’ve studied spray applications in a diversity of crops, both broad acre and specialty, but perhaps nothing is as challenging large tree nut canopies. Australia’s macadamia orchards can form >10 metre high, >4 metre deep canopy walls! So in writing this article I face the opposite situation I normally encounter when advising on airblast […]

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Nozzle Sizing and Calibration Charts

Application Chart (metric)

Need to find the right nozzle size for your application?  Sometimes a simple chart is the easiest way to figure things out.  Print it and place it in your sprayer cab. In this chart, identify your water volume along the top row, and follow the column until you encounter the travel speeds you’re interested in. […]

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How to Nozzle an Airblast Boom

There’s a certain deer-in-headlights expression that creeps onto a sprayer operator’s face when we start talking about nozzles. I profess some sympathy for my field sprayer clients given the overwhelming variety of nozzle styles they must choose from, but I reserve most of it for the airblast operators. The reason being that horizontal booms carry the […]

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Calibrate Airblast Output

(A) Suggested spray distribution for airblast sprayers on classic spindle apple trees. (B) If the canopy is of uniform depth and nozzles are approximately the same distance-to-target, such as a vine or high-density apple, spray distribution should also be uniform (i.e. each nozzle sprays the same rate). These distributions may change when there is fruit to protect.

Airblast operators have to know the volume of spray mix their airblast sprayers emit for a given area. Generally, this is referred to in L/ha or US g/ac. This information must be recorded to comply with traceability requirements (e.g. CanadaGAP) and to ensure they are following the pesticide label. There are many ways to determine this […]

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