Spraying - low pressure

[MattR]

Spraying cereals, currently on red (04) flat fans. Wanting to reduce water volume to around 145-150, at 11k that would mean 2 bar or just over. Should that be ok or is it too low for some things - ie get a set of blue nozzles instead?

 

[Jon 3085]

I always spray at 2.1 bar with 04 nozzles, never had a problem.

 

[Chae1]

I prefer higher pressure to improve penetration. Generally 3 bar.

 

[Bobthebuilder]

Won’t get a very good spray pattern with 04s at 2bar as it will be a course spray, also if using any powder/granular based chemicals more chance of blocked nozzles at low pressures if not perfectly mixed

 

[Chae1]

What pressure do anti drip valves open?

If you slow down much or when turning them on at ends I would imagine they take a while to open at 2 bar.

 

[robbie]

I'd go down a size to blues or what ever suits your rate and speed and will be working at about 3 bar.

 

[fudge]

Spraying cereals, currently on red (04) flat fans. Wanting to reduce water volume to around 145-150, at 11k that would mean 2 bar or just over. Should that be ok or is it too low for some things - ie get a set of blue nozzles instead?

Why not increase your forward speed to 12k? It’s crazy buying a whole set of nozzles for such a minor change. TBH I would be astounded if you didn’t do a decent job at 2 bar 150lt/ha at T1.

 

[Kildare]

Yea 12k on reds works out about 145lts

 

[MattR]

I'd go down a size to blues or what ever suits your rate and speed and will be working at about 3 bar.

think I'll do that, thanks for the replies.

Why not increase your forward speed to 12k? It’s crazy buying a whole set of nozzles for such a minor change. TBH I would be astounded if you didn’t do a decent job at 2 bar 150lt/ha at T1.

Yeah certainly could do, although I often find 11k plenty fast enough on a few of our steep/awkward bits. At what speed does efficacy start dropping off - don't they say about vortices behind the boom at higher speeds? (I know we're only talking +1k so guess it doesn't make much odds?)

On a similar subject, as I said I do everything with flat fans at present. Don't have a big area to spray so I can afford to be fairly picky with conditions (though in a reasonably windy area) - but wondering whether it would be worth having a set of air induction nozzles to switch over to just in case. How much more wind will they cope with?

 

[David.]

I use blue bubble jets for everything now, 2bar ok if conditions are a bit iffy, like to use them at up to 4 bar when conditions really nice for finer droplets and good coverage.

 

[Chae1]

think I'll do that, thanks for the replies.



Yeah certainly could do, although I often find 11k plenty fast enough on a few of our steep/awkward bits. At what speed does efficacy start dropping off - don't they say about vortices behind the boom at higher speeds? (I know we're only talking +1k so guess it doesn't make much odds?)

On a similar subject, as I said I do everything with flat fans at present. Don't have a big area to spray so I can afford to be fairly picky with conditions (though in a reasonably windy area) - but wondering whether it would be worth having a set of air induction nozzles to switch over to just in case. How much more wind will they cope with?

I use both and find bubble jets very effective at reducing drift. Would use bubble jets 90% of the time. If your nozzle holders can take several nozzles it doesn't take long to swap over.

 

[robbie]

I was on flat fans but several years ago tried a set of guardian airs with the intention of using them for fungicides and when conditions were iffy and use FF most of the time but it soon got so I was using the GA all the time and they have been my one and only nozzle for a long time now.

A few weeks back I caught a wing tip and broke a GA(they are quite venerable) and I didn't have a spare so put a same colour FF on instead and the difference in drift was outstanding.

 

[cricketandcrops]

GA are the best IMO if just want one nozzle. I have 04 for pre em etc and 03 for everything else……try to run around 3 bar

 

[robbie]

GA are the best IMO if just want one nozzle. I have 04 for pre em etc and 03 for everything else……try to run around 3 bar

Agree, 3bar seems to be there sweet spot, I'll alter my water rate a bit if I want to go at a different speed to keep the pressure about right. I will go up to 4bar and down to 2.3ish. they seem to be streaky at 2 and below but efficiency still seems good when running at that around headland for lerap 3 star.

 

[cricketandcrops]

Red 04 at 2 bar applying 180 lt/ha at 9 kph

 

[Bobthebuilder]

Mainly use reds for 200L
Blues 120-170L ( normally 150L)
Also have a set of lilacs in the triple holders for less than 120 but never used them yet in 3yrs
Speed 10-14kph depends on field

 

[Bury the Trash]

trouble is blues ..03's will block easier if theres reason
despite being 'advised' many times over the yrs that 3 bar is what should be used i like 2.5 or even a bit less, i must admit, less drift on flat fans as well but it s not proper coarse either

 

[Brisel]

Most of the LERAP 3* drift reducing nozzles only have that rating at 2 bar. I wouldn't want to go much lower than that & personally, I prefer to run a smaller nozzle at 3 bar most of the time so at least I have the option to slow down on headlands if it's a bit rough or breezy.

Nozzle choice depends on what you are trying to hit and how your product works. Small target = higher volume and/or a finer spray. Large target = you can get away with a more coarse spray that gives you the widest window of opportunity to work. Contact only product = fine spray. Systemic/translocated product = ok to be more coarse.

A flat fan is the best for most jobs but is the most drift prone. I use a air indiction nozzle for most work that puts out a finer spray quality than the really coarse "contractor nozzles" designed for getting through a big workload when the conditions aren't ideal. Bubblejets and Guardian Airs are at the finer end of the scale.

Nozzle guide chart

 

[Chae1]

Most of the LERAP 3* drift reducing nozzles only have that rating at 2 bar. I wouldn't want to go much lower than that & personally, I prefer to run a smaller nozzle at 3 bar most of the time so at least I have the option to slow down on headlands if it's a bit rough or breezy.

Nozzle choice depends on what you are trying to hit and how your product works. Small target = higher volume and/or a finer spray. Large target = you can get away with a more coarse spray that gives you the widest window of opportunity to work. Contact only product = fine spray. Systemic/translocated product = ok to be more coarse.

A flat fan is the best for most jobs but is the most drift prone. I use a air indiction nozzle for most work that puts out a finer spray quality than the really coarse "contractor nozzles" designed for getting through a big workload when the conditions aren't ideal. Bubblejets and Guardian Airs are at the finer end of the scale.

Nozzle guide chart

What sprayer do you have at new place?

 

[Brisel]

What sprayer do you have at new place?

A Bateman RB35 and a JD 740i trailed. Both 24m and a few years old each. The Bateman has single nozzle holders but the JD has 4 nozzle ends. Both currently running 035 Guardian Airs at 140 litres/ha for most jobs at this time of year. 3D Defy angled nozzles in the autumn & early spring. I manipulate water volumes if I need a finer spray. Lots of spread out blocks of cropping on 12 units means little gain from lowering water volumes to 100 l/ha as each block is 1 or 2 loads anyway.