Electrostatic Foliar Backpack Sprayer

[FruitFreak]

During a conversation with a representative from Organic Laboratories about which foliar product would be optimal for my young mango trees he asked me what application method would be used.  I informed him that I have a non motorized 5gal backpack sprayer and he straight up told me "before wasting money on product purchase a motorized mister with an electrostatic conversion kit"  He cited stihl and solo versions as good misters.  Hearing this from a rep who sells Ag products kind of drove home just how important it is to have the right equipment.

http://www.spectrumsprayer.com/backpack.html

Is there anyone out there who is using electrostatic equipment?  This to me sounds like a "must have" for any foliar application.

[Cookie Monster]

That's really interesting. I use the solo 451, and I do note that it has a tendency to only coat the site being directly hit. I might see if they have a kit for the solo 451.

If your operation is large enough to warrant the cost, a backpack mister like the solo 451 or the equivalent stihl is a no brainer. I can cover 30 - 40 trees in just a matter of minutes -- all without runoff. I've used many different types of sprayers, and there is absolutely no comparison. The other sprayers are stone age by comparison.

I liked the solo 451 over the stihl, since it has the option of a water pump, which also functions as an agitator. Stihl also sucks in that they have a no-internet sales policy, meaning that you have to schlep down to a brick and mortar store and deal with lack of price competition to buy one.

[FruitFreak]

That's really interesting. I use the solo 451, and I do note that it has a tendency to only coat the site being directly hit. I might see if they have a kit for the solo 451.

If your operation is large enough to warrant the cost, a backpack mister like the solo 451 or the equivalent stihl is a no brainer. I can cover 30 - 40 trees in just a matter of minutes -- all without runoff. I've used many different types of sprayers, and there is absolutely no comparison. The other sprayers are stone age by comparison.

I liked the solo 451 over the stihl, since it has the option of a water pump, which also functions as an agitator. Stihl also sucks in that they have a no-internet sales policy, meaning that you have to schlep down to a brick and mortar store and deal with lack of price competition to buy one.

Indeed I will be getting a motorized sprayer likely the solo.  It also sounds like a no-brainier to use a conversion kit that positively charges the solution as it exits the sprayer so that the particals adhere to the negatively charged tree.  Come to think of it, why isn't this "standard" for all sprayers..,

[pineislander]

I've always used a spreader-sticker in my mist blower, These products are surfactants which break up the surface tension found on glossy surfaces. When I found that the active ingredient was  sodium or ammonium laureth sulfate, I recalled it was the active ingredient in shampoo and used that ever since, This was on cabbage family plants(very waxy leaves) with BT natural insecticide, but I expect it would work as well on most trees.

Here is a more technical discussion:
http://extension.uga.edu/publications/detail.cfm?number=B1319

[Cookie Monster]

I use a surfactant as well, but it still only coats the side of the object in direct line of spray. The electrostatic sprayer is supposed to coat the backside as well (since particles are "magnetically" attracted to it).

The attachment is about $500 shipped, so it is a sizable investment.

[FruitFreak]

I use a surfactant as well, but it still only coats the side of the object in direct line of spray. The electrostatic sprayer is supposed to coat the backside as well (since particles are "magnetically" attracted to it).

The attachment is about $500 shipped, so it is a sizable investment.

Cookie - Maybe you could upgrade your mister and report back to us on the efficiency  

When you think in terms of chemistry it seems like a no-brainer to do the conversion.  It positively charges the spray to adhere to the negatively charged tree/foliage.  Agricultural products are expensive to begin with so you may as well get the most bang for your buck in terms of application effectiveness.  I'll be scheming to pickup a mister and conversion kit asap.

[Cookie Monster]

I'm considering it. Right now, I have to do a 360 around most trees to get good coverage.

I'm taking care of about 80 trees right now, so a good set of tools really helps. To maintain a healthy orchard, you really need to be on a frequent spraying program, and being able to cover the entire orchard in 30 minutes on a sunday afternoon means that it's actually something that will get done regularly.

For the better part of a decade, I tried to get by without spraying. But I've come to the conclusion that you really need to spray for 2 things here inland FL:

• Fungus -- Most mango trees and all pomegranates need regular fungal treatment.
• Insects -- The green leaf hopper can be a serious pest on annonas, to the point that they fail to grow and / or produce fruit. Citrus is also near impossible to grow without a regular insecticide application. Then there are some other minor pests, such as scale of various types that infect ambarella, star fruit and others.

I've found that I don't really need to apply micronutritionals via foliar means. As long as you're not on dade marl, a regular fertilization regimen does a great job of keeping trees healthy. On sand, you can adjust the pH very easily with sulfur, and on other soils, you can build a layer of compost and saturate it with fertilizer to build up high nutrient levels.

Cookie - Maybe you could upgrade your mister and report back to us on the efficiency  

When you think in terms of chemistry it seems like a no-brainer to do the conversion.  It positively charges the spray to adhere to the negatively charged tree/foliage.  Agricultural products are expensive to begin with so you may as well get the most bang for your buck in terms of application effectiveness.  I'll be scheming to pickup a mister and conversion kit asap.

[CTMIAMI]

I have used both stihl and solo. Both Work good I prefer the Stihl  I have done 20 large avocados trees with 4 gallons, in about 10 minutes. I really don't think the electrostatic conversion is worth the price unless you are going to use it all day. Now let me  warn you. I'm 67 in relative good shape I don't think I could carry the equipment and the chemicals for a long time. I recently did 40 trees with the stihl and was done for the day.

[Cookie Monster]

OK. What did you like better on the stihl?

Yah, the backpack sprayer can get heavy, especially when full. But a full manual backpack sprayer is just as bad or worse :-).

Update:

I was just checking the stihl vs solo, and I think the solo might be the better unit in terms of function and use:

Stihl pros

• Product quality might be a smidgen better?
• The lever to turn on / off the supply line is on the throttle handle for one handed operation. This would be handy, as I'm constantly using my left hand to turn the supply on and off with the solo.
• The SR 450 can spray dust and granular as well as liquid. (I actually consider this a con, as it means extra parts and configuration options that I'll never use. We don't use dust here, and it's a poor choice for spreading fertilizer...)

Solo pros

• 5 pounds lighter -- that's a lot of extra weight to carry around on the stihl!
• Much higher CFM (542 stihl vs 824 solo). (I think the motor turns at a much higher RPM.)
• Built-in agitation with the optional pump. This is really nice, especially for heavier mixes, such as sulfur. It's also nice to be able to just toss mix in the container without worrying too much about even mixing. The stihl optional pump doesn't agitate from what I can see.
• I think the motor might be a little quieter, though you still need ear protection and it's still really loud.

I have used both stihl and solo. Both Work good I prefer the Stihl  I have done 20 large avocados trees with 4 gallons, in about 10 minutes. I really don't think the electrostatic conversion is worth the price unless you are going to use it all day. Now let me  warn you. I'm 67 in relative good shape I don't think I could carry the equipment and the chemicals for a long time. I recently did 40 trees with the stihl and was done for the day.

[Cookie Monster]

OK. I'm buying one :-). I'm just waiting for the invoice. (I found a place that sells them for a reasonable price.)

I guess they are used fairly heavily by cannabis growers...

Looks like they are built to fit the stihl sprayers, but with some home cheapo parts, I should be able to fit it to the solo.

Check out the difference between electrostatic and non here. The apple on the right is what everything looks like after I spray it with the solo now. https://youtu.be/4nUN-gfwH_g?t=48s

PS -- Stihl does make a lower priced unit (https://www.stihlusa.com/products/sprayers/backpack-sprayers/sr200/), which I retails for around $400 and is compatible with the electrostatic nozzle. Combined price for the two would be around 700... which isn't too bad for such a nice setup.

[Mark in Texas]

An investment in an electrostatic sprayer, either a backpack (if you got the strength and endurance), or trailer or tractor 3 pt. mount is a must for you guys.  I've seen demos in vineyards where they placed cards inside the canopy along the row, sprayed using a trailer rig, and then checked out the hidden cards.  They were saturated.

I made my sprayers investments 12 years ago  (backpack, trailer 5 HP gas powered wand and boom, tractor mounted airblast) but if I had to do it all over again I'd go with electrostatic not only for efficiency but for the savings on materials.  I rotate in and out of quite a few fungicides with different chemistries  and some go as much as $230/gal.

Carlos I hear you on the age and back thing.  I'm also 67 and am now recovering from a major surgery 2 weeks ago to lumbar discs L1-l5.  It's been hell.

[Cookie Monster]

I ordered the electrostatic nozzle. For anybody who's interested, groit.co has the nozzles for around $360 shipped, which is a pretty reasonable price for those.

I'll let you know how it works in the next couple of weeks. It's probably going to take me a weekend to get it hooked up.

[CTMIAMI]

Jeff can you post a picture of what you got? Is it for The Solo?

[Cookie Monster]

Hey, Carlos. I got the Spectrum 3010 (http://www.spectrumsprayer.com/backpack.html). The device is actually made to fit the Stihl 200, 420, and 450 sprayers, but everybody I've talked to says that it can be connected to the solo 451 with parts from home depot.

I'm still waiting on the part. I'll let you know when it arrives.

Jeff can you post a picture of what you got? Is it for The Solo?

[Guanabanus]

Sounds very good.

[FruitFreak]

So pumped to see Cookies setup and hear about the conversion.  I'll be throwing down on a mister + electrostatic next year!

[Cookie Monster]

OK, I'm going to try to get this setup this weekend. I'll be the guinea pig and see if this thing does any good, but there is considerable evidence that the electrostatic head may not help at all. In fact, with the stihl 420, coverage and canopy penetration was actually better without the conversion kit.

From Spectrum's own site, you can see that leaf coverage is lower with the spray head activated (see the table at the bottom of this page http://spectrumsprayer.com/research_9.html). (It's odd that they even posted that on their site :-).

This research project also shows lower coverage with the electrostatic head installed (see figures 4 and 5 http://www.med.navy.mil/sites/nmcphc/documents/nece/canopy-penetration-and-deposition-of-barrier-sprays-from-electrostatic-and-conventional-sprayers.pdf)

And this research project also shows lower coverage and less canopy penetration with the electrostatic head installed (see figure 6 http://www.med.navy.mil/sites/nmcphc/documents/nece/canopy-penetration-and-deposition-of-barrier-sprays-from-electrostatic-and-conventional-sprayers.pdf)

All tests used the stihl 420, and since the stihl lacks a pump, the flow of liquid is greatly reduced (probably due to change in airflow near the venturi). The authors theorize that this has resulted in less canopy penetration (they made some argument about the higher density of the particle cloud protecting particles). They also point out the fact that the charge imparted on the particles is low.

My solo 451 has a pump, so flow rate should not be affected. However, the low charge to mass ratio will probably get worse with greater fluid flow, so there is probably a thin possibility that it will result in much greater deposition. But I'm going to give it a shot :-)

Interestingly, the 2009 research article concluded that there was no difference between uncharged and electrostatic sprayers -- ranging from the big truck mounted ones to the small backpack sprayers. I think there is a narrow range of use cases where the electrostatic units actually work better.

PS -- I am happy to report that the spray head fits perfectly on the solo 451 without modification.

[Cookie Monster]

I finally found a research project showing increased coverage from the spectrum attachment. This one is from when the company name was Southwest Sprayers, but the attachment was the same. The only difference is the model of backpack sprayer used -- a Hudson PortaPak vs the Stihl. Test results showed double the rate of coverage: http://www.biodiversitylibrary.org/content/part/JAMCA/JAMCA_V13_N1_P090-091.pdf

[Cookie Monster]

And the final verdict is ... I see no "wrap around" effect in my tests. I'm going back to the plain old spray head.

Update: I had it connected wrong. It's not compatible with the solo 451 motor. See below...

[cos]

bummer thanks for being guinea pig

[Cookie Monster]

:-) I figured it was worth a shot. Bummer, cause that would have really helped coverage.

bummer thanks for being guinea pig

[Cookie Monster]

OK Good news! (but bad news for me :-()

I was just talking to the guy I bought the part from and it looks like the Solo may not be compatible with it. The ground lead is supposed to be attached to the motor chassis and the hot lead attached to the spark plug -- to send the full multi-thousand volt magneto pulses to the charging device. However, on the solo, the motor cuts out in this configuration (it robs too much electricity from the spark plug), so I tried connecting the ground lead to the ground (via a chain that drags on the ground). This apparently doesn't provide enough voltage.

Any electrical engineers out there who know of a way to fix this? Maybe if I put a capacitor in the circuit?

[pineislander]

Generally, the stop button on all small engines shorts out the spark plug to ground. If the electrostatic part sold provides a circuit between the spark plug and ground, the engine will stop. Doesn't matter if it is Stihl, kawasaki, solo or Briggs/stratton. I don't know what they were thinking 

[Cookie Monster]

There should be some internal resistance in the electrostatic charger unit. It works fine on the stihl and the hudson. The guy I bought the part from put me in contact with the patent holder and inventor of the device, so we'll hopefully get a work around figured out soon.

Generally, the stop button on all small engines shorts out the spark plug to ground. If the electrostatic part sold provides a circuit between the spark plug and ground, the engine will stop. Doesn't matter if it is Stihl, kawasaki, solo or Briggs/stratton. I don't know what they were thinking

[FruitFreak]

There should be some internal resistance in the electrostatic charger unit. It works fine on the stihl and the hudson. The guy I bought the part from put me in contact with the patent holder and inventor of the device, so we'll hopefully get a work around figured out soon.

Generally, the stop button on all small engines shorts out the spark plug to ground. If the electrostatic part sold provides a circuit between the spark plug and ground, the engine will stop. Doesn't matter if it is Stihl, kawasaki, solo or Briggs/stratton. I don't know what they were thinking

Any updates on this?