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Discussion in 'Pesticide & Herbicide Application' started by ed2hess, Feb 23, 2013.
...and/or other things through drift.
Next question is what nozzle to use. Is the air induction nozzles
the best way to reduce drift?
Where do you get the information related to how high the nozzle should be off the ground and spacing of nozzles. On my present boom they are spaced at 30 inches. I had a problem with gaps not covered. I guess I had the boom down to low?
As Ric stated, nozzle output depends on pressure. Yes, you need a pressure gauge. Half as much pressure will not reduce the flow by half--it does not work that way. Sorry. The gallons per minute from each nozzle depends on the pressure--you just have to try it , and measure the output.
The gallons per thousand sqft also depends on the speed. If you double your speed--half as much gallons per acre--and your tank goes twice as far. Not likely to be practical, of course. But increasing your speed would apply less gallons per acre.
That info would be in the nozzle catalog/data tabulations. I use AI110 nozzles at 20" spacings on the boom for all of my herbicide applications. The degree of the fan tip and the spacing determines how high the boom needs to hang off the ground. In the case of 110 degree tips spaced at 20", that is as low as 16". For 80 degree tips spaced at 30" the boom needs to be 28" off the ground. One more thing: the higher the boom, the more the spray will drift. 80 degree tips may put out a coarser droplet pattern compared to a 110 degree tip. In my experience, the fact that an 80 degree tip set always has to be held higher tends to cause that to drift more.
That explains my preference for the AI110 nozzles at a 20" spacing. There is not a lot of drift or distortion of the spray pattern until the wind gets above 15 MPH. I do not have to apply in totally still conditions that make ester herbicides hard to use. But the label is the law and I suspend operations when weather conditions are such that off target movement of herbicides is likely. I know that conventional flat fan nozzles are drift prone at wind speeds above 5 MPH.
The Ric A Green ( a Walker Lawn mower converted to Spread & Spray) actually has a boom 7 inch off the ground and 110 Degree nozzles at 14 inch spacing. While 20 inches by 20 inches is the normal recommend boom height and spacing, that doesn't mean it is written in stone. With just a little tweaking you can design what fits your equipment and program. In my case I wanted the boom out front and low to stop over spray. I work on very small yards with lots of Island etc. I like the Walker because it is so maneuverable and I can watch it all the time. The Boom is attached to the mowing deck carrier.
I am staying out of discussion about Nozzle selection because it opens Pandora Box because their are so many different nozzles. However I will second Greendoctor about air induction nozzles helping to control drift. PSI of course is a big factor. Most Nozzles are rated at 40 PSI. Go above or below that pressure and flow quickly changes big time.
Ric's Ride, my 150 gallon Toro Fire Ant ride on sprayer went from 3 Gallon per thousand to 5 gallon per thousand by increasing the PSI from 55 to 100 PSI. This also require using a high pressure electric Solenoid valve. Ground speed stayed the same as did the Nozzles, only the PSI changed. In the case of Fire Ant Spraying the increased out put didn't burn or kill grass. However It would not help having extra Insect released into the environment. Once again a gage in plain sight can help you keep calibration stead. Also a gage can spike in pressure letting you know there is a blocked nozzle that needs clean.
Can you give me a pointer to that specific nozzle it woud help. I understand the need to get the pressure gage to getting the flow out of that nozzle correct. I understand the spacing and height I want to get more acreage by change to a lower flow nozzle. I understand that my mix concentration must changes as I reduce those nozzle sizes. But is there some wisdom that says those small nozzles clog a lot so stick with _______? Or is the drift just too great with low flow nozzles?
This is what the Walker set-up looks like. I was running the test to determine flow rate. Don't make any conclusions about the height of the boom......It is wired up ....I simply move it up/down until the spray pattern just touch.
This is teh pump and I had it turned up so that I would get a good
stream from my wand
Would a rainbird irrigation pressure gage work? By the way we have a sprayer kit ordered for the used zplugger we just bought off lawwsite. We can't get the $1600 computer/pressure/speed control put on our zplugger it
is too old. So.....the old man will try to get it calibrated.
That link to the Rittenhouse catalog page is a good start for nozzle info. The best place is the Teejet website. I can tell you that ideal operating pressures for an AI nozzle range between 40-90 PSI. Of course, drift control is good at 40. With the configuration I have given you, I have applied as low as 20 gallons per acre and still gotten good weed control. I am not comfortable with testing the concept of depending on one droplet per weed being enough to kill. The nature of the herbicides I use is also a little different from you standard Three Way amines. The actual spray normally works on foliar contact, systemic activity, and soil activity. Less than a full coverage wetting spray wastes the contact aspect of the spray and I would like to not depend on lateral diffusion of the spray droplet on the soil.
Listen to Ric about the pressure gauge. All of my equipment from the truck mounted 10' boom down to the single nozzle hand piece has both a pressure gauge in front of my face and a means to adjust the pressure on the fly. There is no fumbling about. In the case of the 10' boom, application rates and pressure are controlled via a Teejet digital controller. I get a second to second readout as I am spraying. The hand held piece has a regulator and gauge. Fixed output nozzles are at their fullest potential when you have control over pressure and travel speed.
No assumptions will be made about the boom height. Although you now know what you need to do. It appears that it is easy enough to change the nozzle spacing by adding more nozzle bodies and hose. I really prefer an engine driven pump. Electric pumps do not provide enough volume and pressure unless we are talking about a huge one with a high amp draw. Even then, for what I do, I regret buying a Hypro D30 as my pump. A D50 or D70 would be better suited. I am on the edge of pump performance when spraying at 100 gallons per acre.
Subscribed..... Ric, Green Doc, and Riggle you guys are awesome. Thanks for the wisdom you all share.
The one big guestion I need answered is what specific nozzle to put
on this boom to replace mine to get more acreage and less mist? And what about air induction nozzles....good or bad or nobody runs them yet?