In this episode of Exploding Sprayer Myths, we lay out four steps to determining the most appropriate spray volume required to achieve good coverage.
Joined by show-stealing Dr. Doug Baumann, and with the help of a lot of caffeine, we learn that there’s no silver bullet to choosing a spray volume.
Special thanks to Syngenta, Honeywood, and to Real Agriculture.
Buzzwords: Addictive vocabulary with a shelf life.
We love these terms, and they seem to make their way into our language virtually overnight. But perhaps it’s gone too far…
“At the end of the day”, what do these buzzword-laden conversations mean?
Do our “stakeholders” even know what we’re talking about?
Unfortunately, buzzwords are “the new normal.” And that means we have to “drill down” a bit to find the “actionable items”.
Watch as Jason and Tom raise this to a whole new level… and believe it or not, this really is a conversation about sprayers.
It’s a new season of Exploding Sprayer Myths so we’ve got a new opening sequence!
In this episode we demonstrate the importance of nozzle spacing, spray angle and boom height. We also turn a hapless pineapple into a projectile and spray dyed antifreeze on a cold winter day.
Learn more about how boom height affects spray deposit uniformity, and why that should concern you, by going here.
This episode was filmed on location at the Syngenta Honeywood Research Facility in Plattsville, Ontario. We thank them for generously allowing us to commandeer their facility and staff for the day.
And of course, none of this would be possible without the talented staff at Real Agriculture. Make sure you tune into RealAg radio.
A little extra fun:
We received this email after a grower heard Tom speak at a meeting. A compelling observation about how nozzle spacing and drift affects men everywhere:
Tom: I really enjoyed your talk in Humboldt yesterday. During the coffee break immediately after, I went to the washroom and noticed 3 guys spread evenly across 5 urinals. Wow. Talk about worrying about spray drift. When I returned to my table and told my wife of my findings, she commented that it must have something to do about the distance to the target, as it couldn’t possibly be that the pressure was too high!
A very common question we hear at sprayer demonstrations is:
“I want to drive the spray deeper into the canopy – does higher pressure help?”
Well, here’s the classic government answer:
“…yes and no.”
It depends on two things. First, the size of the droplet and second, your tolerance for drift (ours is almost zero, BTW). The following video explains how Fine droplets behave very differently than Coarse droplets. It’s always nice to get outside and toss a few balls around:
Well, that last statement in the video isn’t strictly correct…
It’s true that changes in pressure have greater impact on the momentum of coarser droplets, but there is some impact on finer droplets, too. Sufficiently high pressure makes for a finer spray quality and finer sprays have been shown to penetrate dense canopies more effectively. We have seen improved canopy penetration in ginseng, field peppers and matted-row strawberry using finer spray under higher pressure. If pressure is high enough, it will create air-inclusion and impart additional momentum to even Fine spray droplets over a short distance, but it’s a case of diminishing return. That is, it takes a lot of pressure to do it and relatively speaking they only got a bit faster/further. In our work, we used pressures between 90 and 300 psi. Excepting hollow cones, that’s generally on the upper end, or beyond a nozzles rated pressure range and it may even be outside the pumps capacity.
The reason we downplay pressure as a tool for improving canopy penetration is because finer spray under high pressure causes unbelievable drift. A fraction of the spray does get deeper into canopies when you “fog it in”, but the plume of spray blowing beyond the sprayer is entirely unacceptable. Slowing down the travel speed, spraying on cool, humid, low-wind days and lowering boom height can help, but in every trial where we’ve used high pressure and Fine spray quality, we see the image below… or far worse:
The compromise in canopy penetration is to use a Medium spray quality and higher water volume. Stay within the pressure range the nozzle requires to achieve that Medium spray quality. If canopy penetration is still insufficient, consider canopy management (like planting density and pruning) and explore drop-arms to direct the spray, or booms that offer an air-assist or air-deflection option (a few shown here) to entrain and carry spray into the canopy.
Don’t use higher pressure to increase canopy penetration.
It’s been quite a ride. Here’s episode six of “Exploding Spray Myths”. Real Agriculture helps us share an important message about why sprayer clean out involves so much more than just the tank. If you think you know what we’re covered with, we’re accepting guesses.
And please, don’t blow into nozzles, even if they don’t touch your lips. Blowback is a real thing…