Mode of Action and Spray Quality

The decision on application method for herbicides boils down to two main factors: (a) target type and (b) mode of action. In general, It’s easier for sprays to stick to broadleaf plants on account of their comparatively larger leaf size and better wettability compared to grassy plants. There are exceptions, of course – at the […]

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How to use Airblast Nozzle Tables

The author looking up nozzle rates during a spring calibration. The operator was running at 190 psi, but the catalogue only listed 180 psi and 200 psi. When span is only 20 psi, it’s fairly safe to approximate the output. When the table only lists in 50 psi increments, it is more difficult to determine the rate without testing the output. This issue usually occurs at pressures above 200 psi, and that’s very high for most horticultural operations. Consider using a lower operating pressure, if possible.

Airblast operators should know how to read a nozzle table. They are found on dealer and manufacturer websites as well as in their catalogs. Table layout varies with brand, but they all relate a nozzle’s flow rate to operating pressure. The better tables also provide the spray angle and the median droplet size (i.e. spray […]

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How Low Can You Go?

There’s a lot of talk about lowering the boom to reduce drift and make twin fan nozzles more effective. But how low can we actually go with a boom before striping becomes a problem? We’ve done some calculating and have come up with answers. First, a few guidelines. Tapered flat fan nozzles require overlap to […]

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Boom Heights at Fan Angles Worksheet

Use this spreadsheet to calculate the minimum boom heights needed for various applications. Some caution: The values are theoretical and assume the fan angles are accurate. Some nozzles don’t produce the advertised fan angle. Enter your actual angle in the spreadsheet The theory assumes that the droplets at the edge of the fan always move […]

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