Backpack sprayer/fogger?

[ning]

I've been looking into getting a backpack fogger for spraying horticultural oil in our little orchard.

We've used a small powered sprayer unit before, but it broke rapidly, and in researching a replacement I ran into the fogging idea, which is that the fog of stuff makes a much more efficient cover of the whole tree - efficient in time and the volume of "stuff" used.

Note that the horticultural oil (neem oil) is emulsified and is basically a water solution.

I'm curious about the Stihl SR 200, 430 and 450 units. Someone local around here (on "nextdoor") says he's got the 430 and uses is for neem oil and it works great; I'm curious if anyone out in TBN-land has used one of these units for the same - or a similar non-Stihl unit.

Most of our trees are dwarf- to semi-dwarf; I keep them pruned to about 10' height.
So one question is whether the SR200 will fog that height well enough; there are some indications that you need to add a power pump to help move the fluid into the air stream on the SR 200 to reach higher elevations; I believe the SR 450 comes with it, the SR 430 not. Unclear.

The 200 is a lot cheaper than the 430/450, but it's got 1/3 the engine (and weighs 9 pounds less). It's also got a smaller tank, but for our use its tank is a fine size and I'm not expecting to carry a full load in any of them.

Any experience with any of these foggers? (If you do have experience but it's for insecticide, I'm still interested in how you like the machines).

 

[dieselscout80]

We just have 2 peach trees, 1 apple tree and a pear tree.

Could I just put the neam oil in a sprayer to apply it to our trees?

I did see an add on to a leaf blower on Amazon. I wonder how it would work?

https://a.co/d/9jVLtFV

 

[ConawayFarms]

I’ve used a similar one on a small orchard, and getting even coverage really makes a difference. The SR 430 sounds like it might be a good balance between power and ease of use for your 10‑foot trees. I’ve seen some chatter about the SR 200 needing an extra pump for higher coverage, so if you’re aiming to spray up to the top, that might be something to consider.

 

[part-time-Farmer-NC]

We use the 25 gallon UTV sprayer from agrisupply for our 190+ fruit trees, 100+ grape vines. Thankfully we haven't had a need/don't to spray blackberries or blueberries.

That sprayer worked great for about 2 ish years then I replace the pump and we are off to the races again.

Prior to this I indeed did the pump up sprayers. Worked fine, reach wasn;t as good but it met our needs as the trees were smaller then.

 

[ning]

I did see an add on to a leaf blower on Amazon. I wonder how it would work?

These backpack sprayers are basically a backpack blower + tank + metering device, so similar in concept.

I’ve used a similar one on a small orchard, and getting even coverage really makes a difference. The SR 430 sounds like it might be a good balance between power and ease of use for your 10‑foot trees. I’ve seen some chatter about the SR 200 needing an extra pump for higher coverage, so if you’re aiming to spray up to the top, that might be something to consider.

From what I can tell, all three units (200, 430, 450) require the extra pump for higher angles - this is found on all three product pages:
"The pressure pump kit is recommended for applications in which the spray tube is held at an upward angle of more than 30 degrees in order to maintain a consistent discharge rate."

Given that my trees are pretty short, I can be well within the maximum spray range of even the small unit (SR 200 - 29.5' max range) and the top of the tree is below 30° inclination, so I suspect they'd all manage similarly; the bigger units would likely be used at less than wide open throttle.

We use the 25 gallon UTV sprayer from agrisupply for our 190+ fruit trees, 100+ grape vines. Thankfully we haven't had a need/don't to spray blackberries or blueberries.

That sprayer worked great for about 2 ish years then I replace the pump and we are off to the races again.

Prior to this I indeed did the pump up sprayers. Worked fine, reach wasn;t as good but it met our needs as the trees were smaller then.

We also tried the 25 gallon type (20 gallon I think) but it's pretty clear from reviews everywhere that all of the smaller units are pretty iffy on quality and our experience was similar; looking for a decent one was where I encountered the backpack sprayers, and everything indicates that they use less product and get a better coverage, more quickly - the time being pretty key for me as like everyone I've too much to do already.

 

[Carl_NH]

We have two Stihl - an SR400 older unit and a newer SR450 and use them for fogging oils to prevent and manage insects and wiltpruf in the fall, then mosquito fogging in the summer.

Both units can fog up to 15-18' from the ground but I prefer the older SR400 as it has a smaller nozzle - higher velocity air, vs the 450 has more CFM but lower velocity. My SR450 does not have a pump.

Also there is an air feed to the tank, and if you increase the hole size in the fitting in the tank, it pressurizes the tank better and fogs higher.

I would get at least the 430 and see if they have a removable, narrower tip for the end of the blower to get more velocity get that or fab one out of a plastic bottle etc.

 

[Carl_NH]

The point of the pump and the 30* angle is that once you get the tip of the nozzle higher than the tank and fluid it can't push the fluid to the nozzle (not enough pressure build up).

That's why with the smaller nozzle create back pressure, thus pushing more air into the tank.

Sorta have to use one to understand how they work.

 

[ning]

We have two Stihl - an SR400 older unit and a newer SR450 and use them for fogging oils to prevent and manage insects and wiltpruf in the fall, then mosquito fogging in the summer.

Both units can fog up to 15-18' from the ground but I prefer the older SR400 as it has a smaller nozzle - higher velocity air, vs the 450 has more CFM but lower velocity. My SR450 does not have a pump.

Also there is an air feed to the tank, and if you increase the hole size in the fitting in the tank, it pressurizes the tank better and fogs higher.

I would get at least the 430 and see if they have a removable, narrower tip for the end of the blower to get more velocity get that or fab one out of a plastic bottle etc.

The point of the pump and the 30* angle is that once you get the tip of the nozzle higher than the tank and fluid it can't push the fluid to the nozzle (not enough pressure build up).

That's why with the smaller nozzle create back pressure, thus pushing more air into the tank.

Sorta have to use one to understand how they work.

Ok, this is what I was hoping to see with this thread! Thank you!

 

[Carl_NH]

To get the tops or tips of the trees or high shrubs, you need to create a shower effect with the fogger "pulsing" of the engine or stand further back and let it fall - it's not easy in windy conditions - best to do early AM and no wind. If you have an orchard - do it from a truck or wagon bed with someone driving to gain the height

 

[ning]

To get the tops or tips of the trees or high shrubs, you need to create a shower effect with the fogger "pulsing" of the engine or stand further back and let it fall - it's not easy in windy conditions - best to do early AM and no wind. If you have an orchard - do it from a truck or wagon bed with someone driving to gain the height

Or tractor bucket?