25cm nozzle spacing ?

[Clive]

Just looking at spec for new sprayers and 25cm nozzle spacing is an option

Seems a good idea to improve coverage plus ability with good boom height control to run booms lower meaning less drift demand closer spacing to maintain pattern coverage

Any user experience or has any research or trial work ( @Feldspar ?) been done into the benifit of 25cm over 50cm ?

 

[SilliamWhale]

Does it really matter?

I mean I'm sure its nice to have but will it really make you more money or kill more weeds?

 

[Clive]

Does it really matter?

I mean I'm sure its nice to have but will it really make you more money or kill more weeds?

That’s what I’m wondering and asking if has ever been trailed or on farm real world experience from existing users

In theory if you can reduce drift and / or increase coverage you could maybe get same results at lower doses or do a better job at the same dose rates

Also if drift is reduced by lower boom height what would have been days to drifty to spray become ok meaning more acres through each machine in less time ?

Theory is good but I’m after real world user feedback

@Tom H what spacing and combination nozzle set are you running ?

 

[Feldspar]

Just looking at spec for new sprayers and 25cm nozzle spacing is an option

Seems a good idea to improve coverage plus ability with good boom height control to run booms lower meaning less drift demand closer spacing to maintain pattern coverage

Any user experience or has any research or trial work ( @Feldspar ?) been done into the benifit of 25cm over 50cm ?

This was covered in the old thread. From memory I found some trial work which showed drift reduced by 56% as the booms went from 50cm high to 25cm high.

 

[SilliamWhale]

This was covered in the old thread. From memory I found some trial work which showed drift reduced by 56% as the booms went from 50cm high to 25cm high.

High or wide?

 

[Badshot]

Double the nozzles means half the size orifice, small orifice means lots of blockages.
Very good filtration required

 

[Feldspar]

High or wide?

High. It was actually 50cm down to 30cm actually from memory. Obviously to do this you need to go to 25cm nozzle spacing.

 

[Clive]

This was covered in the old thread. From memory I found some trial work which showed drift reduced by 56% as the booms went from 50cm high to 25cm high.

I recall reading something about it but wasn’t in the market at the time so didn’t take a lot of notice ! Can you recall who did the trial work ?

 

[Feldspar]

I recall reading something about it but wasn’t in the market at the time so didn’t take a lot of notice ! Can you recall who did the trial work ?

It turns out the maths isn't simple: http://www.holsoft.nl/idefics/pdf/kinevap.pdf. I'd never thought about the effect of evaporation of spray droplets before. But anyway, here's your answer:

http://www.cabdirect.org/abstracts/20013029684.html;jsessionid=D85B3A5DC06D0E56ADCFE925F98617E9

56% reduction in spray drift by going from 50 to 30cm!

I presume, given I've done your work for you, that you have at least solved Fermat's last theorem (not that it matters because Andrew Wiles has already done it).

My memory is good!

 

[B R C]

I don’t doubt some of the current boom height control systems are very good, but can you really run a (wide)boom at 25-30cms? That’s the length of my boot!

 

[Tractor Boy]

High. It was actually 50cm down to 30cm actually from memory. Obviously to do this you need to go to 25cm nozzle spacing.

No you don’t. I’m not sure where this thought of needing to go 25cm spacing to drop the boom below 50cm comes from. If you work out the geometry of a ff 110 degree nozzle, you actually get a double overlap at 35cm not 50.

 

[Feldspar]

I don’t doubt some of the current boom height control systems are very good, but can you really run a (wide)boom at 25-30cms? That’s the length of my boot!

Yes. Had the Horsch on demo last year and it's is quite amazing what it'll do. We ran it at 18kph on a bumpy field and had to stop because we couldn't stay in our seats rather than because the booms wouldn't take it. It's probably the single most impressive bit of tech I've seen.

 

[Feldspar]

No you don’t. I’m not sure where this thought of needing to go 25cm spacing to drop the boom below 50cm comes from. If you work out the geometry of a ff 110 degree nozzle, you actually get a double overlap at 35cm not 50.

Ah, stand corrected. Droplet velocity is higher on an 80 degree IIRC which means faster nozzle to target time with correspondingly less drift.

 

[Campbell]

30cm was the default spacing on French sprayers, still find a few around.

 

[B R C]

It’s interesting, the aim with narrower spacing is to get better coverage and less drift? It would be interesting to compare results and costs with airtec which has been around a long time but seems to have all but disappeared. I ran a 20m airtec for 15 years until last year and the ability to alter spray quality on the move, less drift and everything at 80l/ha was great.

 

[e3120]

33cm & 80 degree nozzles on my relic. Am I behind or ahead?

 

[Clive]

33cm & 80 degree nozzles on my relic. Am I behind or ahead?

Assuming you can run booms at 30cm above crop you are ahead it seems !

 

[traineefarmer]

30cm was the default spacing on French sprayers, still find a few around.

40cm on our 30 year old Berthoud. The need for smaller nozzles compared to our Bateman on 50cm is a pain.

 

[Clive]

I don’t doubt some of the current boom height control systems are very good, but can you really run a (wide)boom at 25-30cms? That’s the length of my boot!

I think you can on the Horsch boom - it really is in a league of it’s own - 36m with double Variable geometry and 6 sensors is more than able to run that low at speed over undulating ground from what I’ve seen so far

But all that undeniably very clever tech comes at a rather large price premium

 

[Properjob]

You must be pricing a Horsch Clive? We have 4+1 on ours, have 03 air inductions for general fungicides/insecticides when breezy etc, then 025 Guardian airs at 25cm and 50cm, the 025's at 50 cm face backwards for spraying at low volumes when conditions allow, the 025's at the 25cm spacing (the +1) face forwards. So for applications such as ear wash, herbicides etc, OSR flowering sprays we use all the 025's to put on 200l/ha, coverage in wind is excellent, can also switch forwards or backwards at 100l/ha depending on application for lower spray volumes. The other two nozzles at 50cm are liquid fert Quintastreams. To be honest with the boom levelling as precise as the Horsch you don't need to spray below 50cm, 30cm is far lower than you realise and drift with spraying at true 50cm crop height is as good as it gets.