Hi Nat,
We found ourselves in your situation three years ago. It took us days to get all our trees sprayed by hand, plus two people to do the job, one driver and one sprayer. We bought a used 100 gal Tifone with a three point hitch, and have been pretty pleased overall. Given what we spray, however, we are not able to use the airblast as efficiently as a conventional grower, spraying two sides at once, skipping aisles, etc. Most of our spray mixes contain EM-1 bacteria, and as other threads in this forum have discussed, there are pressure concerns with regard to damaging/killing the beneficial bacteria you're trying to get out there. We also typically want to spray everything to runoff, so not just a quick concentrate run or fine coverage that the average conventional grower is going for with their airblast.
Our solution has been to go up and down each side of the tree aisle, typically in lowest gear, emitting spray only from one side of the airblast (our tractor is also only 30 hp, so pressure is not great with both sides open anyway). I'm also running the sprayer pump at 200 psi for bacteria-containing sprays, which may even be pushing it, pressure wise. If I'm spraying lime sulfur, copper, or anything else that is standalone, things become slightly more efficient. We also put a handwand attachment on our airblast, so we can switch to that for small trees, where airblast would be a complete waste. It now takes us about a day and a half to do our 1,800 MM111 trees, with one day's worth of airblast getting our 11 year-old 1,000 tree orchard done, then another half a day to get all the residual hand stuff done in our newly planted 800 tree orchard.
Another thing to think about: efficient tank filling. If you're planning on using a garden hose with normal pressure, the benefits of a big airblast may be negated. We took a page from some area conventional growers' playbooks; they often set up pumps in creeks to keep a water cistern filled, then just position the airblast tank underneath a large outlet and dump water in to fill the tank very quickly. We don't have a natural water source, but built a wooden platform about 6 feet high, put a 275 gallon IBC tote on top, and let the hose run in to keep it filled while we spray (need to install a float valve to make this overfill-proof, but haven't gotten around to it). We have a 2 inch pipe outlet running out the bottom, so we can open up the valve on the water tote and dump water in quickly, to fill our 100 gallon tank in four minutes or so, and be on our way back out to spray again.
One limiting factor for us is the 100 gal capacity of the sprayer. We have to fill up 14 times per spray, which is very inefficient, but our orchard rows are very tight, particularly where they meet the fence. I would never be able to make my turns with a larger pull-behind unit. Looking forward to expanding our fence line when we need to replace our deer mesh in another year or so, being able to afford a more powerful tractor, and maybe getting to the point where an upgrade to a larger pull behind airblast makes sense.
We also have trees of varying sizes, even in our fully grown orchard, and one nice thing about having the airblast on a three-point hitch is that I can raise and lower the sprayer to finetune the spray even more. For example, if I've got a few small trees, I lower the sprayer so that the trees and ground get all the benefits of the EM-1, oils, etc. I'm spraying, rather than having most of it go up into the atmosphere, since there isn't a high canopy to catch all the good stuff I blast high up into the bigger trees.
Hope that helps.
Kordick Family FarmWestfield, NC
Zone 7a
Edited 1 time(s). Last edit at 03/04/2021 03:56PM by Brittany Kordick.