Spraying highbush, cane and bramble berries is challenging. Invasive insects such as spotted-wing drosophilla have made canopy management and IPM crucial to keeping the farm clean. And, when the crop scout reports that it’s time to spray, you need enough sprayer capacity to hit the timing window with a sprayer appropriately calibrated to maximize coverage.
The reader should recognize my bias before watching this slide deck: I’m a big fan of air-assist (pun intended). Respected colleagues in university extension and in industry have told me that you can achieve suitable coverage with vertical booms, fixed misting systems and even self-propelled sprayers with 90 foot horizontal booms. These methods rely on hydraulic pressure, and not air, to propel the spray into the canopy. I don’t deny that it’s possible.
However, my feeling is that while you may not need air-assist for early season applications (and/or heavily pruned crops), you will as the season progresses. As crops fill and as pressure for infection or infestation rises, air-assist from an appropriately-sized and calibrated sprayer is the safest bet for uniform coverage.
The following presentation has grown and changed over the years. This version was delivered at GLEXPO in Michigan in late 2016. It covers all these topics and explains my reasoning. If you’re having trouble with it, you may need to update your browser.