Pressure Changes Spray Angles

Soybean demo plot sprayed with a contact herbicide using 110 degree air induction flat fans at 20 psi. The collapsed spray pattern did not overlap sufficiently to burn the entire crop down, leaving a striped pattern and demonstrating the poor coverage.

When we consult a nozzle catalogue we are interested in the flow and droplet sizes produced at a given pressure. Perhaps we should also consider the effect of pressure on spray angle. We have several articles discussing the collective impact of spray overlap, nozzle spacing and boom height on coverage uniformity (Check here and here […]

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Pesticide redistribution: an important aspect of synthetic pesticides

What is Redistribution? If you’re a sprayer operator with some experience behind you, you may have applied mercury arsenate, nicotine, Paris green, or perhaps even DDT. All of these historical pesticides were effective, but they were also toxic to both the applicators and the environment. Fortunately, today’s agrochemical manufacturers produce pesticides that are effective while […]

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Coverage is King

In the case of fungicide applications, subsequent sprays fill in gaps left by previous sprays. If timing is prompt, residual activity will see you through.

We’ve often heard the adage “Coverage is King” but what does that mean, exactly? It means that in order for your spray application to yield acceptable results, a threshold amount of the active ingredient in your tank must end up on the target. But at what point have we achieved sufficient spray coverage without wastefully […]

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Adventures in Lecturing

Harvest is mostly done and growers want to hear what we’ve learned and what’s coming next. Lecture season is upon us once again. In 2021 we’re still finding our way through virtual conferences and hybrid models, but I like to think we’re slowly returning to the in-person format. Just last week I gave my first […]

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Establishing an optimal airblast carrier volume

An orchardist taught me this trick: If you want to know if spray will penetrate a canopy, you should be able to see sunlight through the shadow at high noon.

Thanks to Mark Ledebuhr of Application Insight LLC for his contributions to this article. North American product labels may or may not include carrier volume recommendations. When they do, it could be based on a two-dimensional value like the planted area, or perhaps on row length which is more appropriate for trellised crops that form […]

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