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| Yup thats right. Definitely gets you to a much more meaningful nozzle setup than using like a 110-15 like a lot of guys get stuck at. (Just that size due to the pressure drop).
Depending on the travel speed and total flow you were looking for (e.g. Anything over 15GPA travelling 15mph-ish), there'd be good sense to split the total flow rate into two nozzles.
On the Raven 4 (or any Patriot 2019 and newer I think), in the monitor, you'll see a 'high flow mode' option like you said, and then it asks which nozzle you are using pulsing (e.g. SR110-06 for 10GPA portion), and which is non-pulsing (e.g. MR110-04 for 7.5 GPA portion) for a total flow of 17.5GPA, or whatever you need.
I'm just working on programming it into Tip Wizard right now to help out with a dual nozzle selection, but should be coming in the next month.
Right now, you'd effectively have to search two nozzle selections, one for PWM for a portion of the flow, and the other as a rate-controlled nozzle for the 'remainder' of the flow that you wouldn't be able to comfortably do with the PWM with the ideal droplet size as you want.
The coarser spray seems to help drive the finer spray into the canopy, but it will get stuck likely in the top to mid canopy level. Once that finer spray gets INTO the canopy, that's where all the stem/ground to mid-canopy and up coverage comes from, especially in a complex canopy like beans. So, coarse spray gets the spray where it needs to go, but coarse droplets wouldn't really 'penetrate hard' into the canopy as the pressures wouldn't be there. Most of the 'medium-coarse' spray droplets might be slowed down dramatically by the time they've sprayed like 14-16". At that point it is gravity and wind/sprayer speeed/etc that help it get into the canopy. They will still get to the canopy and agitate it, but it wouldn't be as though the coarse droplets are goign to be water-jetting and shredding the canopy as they are sprayed out at such pressures.
Overall, when selecting which nozzle goes which position, best put the majority of the flow through PWM so you have better control of it (e.g. pressure control, but also turn comp, etc). 2/3 PWM + 1/3 non-PWM would be a good fit. Otherwise 50/50 would be OK too. With changes in speed, the non-PWM nozzle would be lowering your duty cycle a tad if you were spraying slower/etc.
There was a really good relatable study out of UofT that had I think it was Glufosinate trying to kill Pigweed with better coverage. While it'd be a herbicide trial versus your fungicide, the intent was to kill the known-resistant pigweed with better coverage. So, they had a variety of spray nozzle configurations (two angle, straight down, AI, deflector, and a double-down setup (pulsing + non-pulsing) and the double-down style was the best performing in getting coverage in-crop, on a complex weed to hit. They had set it up that the one nozzle was very coarse (coarser than you'd think of when spraying fungicide/Liberty), and the second behind it was a lot finer. Seem to suspect the coarser nozzle acted almost like a water curtain to make sure the finer sprays got down to the canopy where they can zig zag through the canopy better than a coarser droplet could.
Anyway, you are right on the mark there. A whole lot more potential to gain efficiency (if you are tapped out on flow rate through PWM and have to use a REALLY big nozzle to get up to 20GPA), but also would allow you to make more meaningful spray with the same flow rate you wanted.
Hope that makes a bit of sense to you. Let me know if you have any questions,
-Lucas | |
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Nozzle for fungicide
