Trailed vs Self Propelled Sprayer

[quattro]

Was it horstine ? That used to make a lot of their sprayers on 25cm years ago
Does all this expense give better yields or is it down to weather at the end of the day

 

[fudge]

Was it horstine ? That used to make a lot of their sprayers on 25cm years ago
Does all this expense give better yields or is it down to weather at the end of the day

If you have an issue with timeliness better boom control will increase the number of spraying opportunities. That could increase returns if it improves timeliness?

Without doubt the horsch is a step forward in boom control. But for those of us with flat fields and relatively small areas to cover I very much doubt it would produce more crop. Weirdly, it seems, I have no difficulty maintaining a 50cm height over a 24m boom, given our topography, a 12kph forward speed, and a sprayer which is worth £5k at the most.

 

[Properjob]

I agree - we use 25 spacing at 50cm height with AI jets and results are great. A “true” 50cm height that a leab can achieve is different to what some think 50cm looks like !

In theory however they should be even better at 30cm height and 25cm spacing surely ?

The sprayer can do 30cm so can’t think of a reason not to now 80deg AI jets are an option ?

The main reason is the nozzle size required when spraying at 25cm spacing. If spraying at say 100l/ha then you need a stupidly small nozzle, resulting in more drift and blockages. Running anything much smaller that 02’s becomes a pain. So to get something like sensible pressure you would be putting on 150l/ha at 25cm spacing even with 02’s. Don’t forget it’s not just 80 degree angle at 30cm boom height, you are doubling your water volume by having twice as many nozzles per boom section. I find the 25cm option is best when good coverage is required in windy conditions, alternate facing guardian airs putting on 100l/ha each, so 200l/ha actual rate. Rest of the time 100l/ha or less at 50cm spacing or 120l/ha with 03’s, other nozzles are quintastreams.

 

[Richard Smyth]

80 degree nozzles have much less driftable fines droplets as a rule so if running them on 25 cm spacing drift is less of an issue even at low water rates.
I still run 110 degree nozzles at 25 cm because with lower water rates I still need the ability to shut off alternating nozzles to let me spray rough land.

 

[Clive]

The main reason is the nozzle size required when spraying at 25cm spacing. If spraying at say 100l/ha then you need a stupidly small nozzle, resulting in more drift and blockages. Running anything much smaller that 02’s becomes a pain. So to get something like sensible pressure you would be putting on 150l/ha at 25cm spacing even with 02’s. Don’t forget it’s not just 80 degree angle at 30cm boom height, you are doubling your water volume by having twice as many nozzles per boom section. I find the 25cm option is best when good coverage is required in windy conditions, alternate facing guardian airs putting on 100l/ha each, so 200l/ha actual rate. Rest of the time 100l/ha or less at 50cm spacing or 120l/ha with 03’s, other nozzles are quintastreams.

We run 02’s at 50cm and 25cm spacing plus a 03 at 50

That combo working on auto step works at 120 -200 L/ha at speeds from 6-15kph really nicely within a good pressure band and no blockages to date - I did hear people had blockages with 015’s hence the 120 water rate vs the 100 we used to spray at a lot

I would run the same set up of jet sizes but just at lower boom ht and 80deg instead of 110deg

 

[Properjob]

The important thing with the Horsch is to flush the booms everyday and blow out the lines, with such complicated boom plumbing, depending on spec, ours is 4 + 1, so 10 chemsavers per m, they can become problematic with build up of CTL etc. The worst ones are on the centre section. What helps is to take all nozzles off once/twice a season and flush out each complete section one at a time at max pressure. On a more standard boom you may only have two chemsavers per m which are in regular use, so no problem. Have heard when you go below 02's much more of a problem.

 

[Feldspar]

I read recently , on either here or twittter or FB that someone was using alternate nozzles along the boom of a twin nozzle then a straight down then a twin etc. or did I dream it? did you comment on it @Clive ? Sounded an interesting combo of nozzles just wondered how itt worked on pre ems?

I think that's what I am going to do. On the 25cm set, one straight down and one in an angled cap. That way you can go forward and straight or forward and back. The 30 degree angle in the caps impart, very roughly, a horizontal velocity component of about 13kph. Therefore, if angled back, this counteracts the forward component of a droplet's velocity imparted from the moving boom to try and get coverage further down in a larger crop canopy. Would therefore use forward and down for small black-grass, and back and down for something like T2.

 

[Feldspar]

The important thing with the Horsch is to flush the booms everyday and blow out the lines, with such complicated boom plumbing, depending on spec, ours is 4 + 1, so 10 chemsavers per m, they can become problematic with build up of CTL etc. The worst ones are on the centre section. What helps is to take all nozzles off once/twice a season and flush out each complete section one at a time at max pressure. On a more standard boom you may only have two chemsavers per m which are in regular use, so no problem. Have heard when you go below 02's much more of a problem.

Is there an issue with letting the booms get dry? Saw on Twitter an issue with chemsavers where possibly things had dried out and then left a sediment in. I was worried about using the air blow out function if that made drying out easier. Would you suggest rinsing out sets of nozzles even if they haven't been used that day?

 

[Feldspar]

Sorry what I meant was that true 50cm as achievable all day long on a Horsch is as good as it gets, lowering to 30 cm doesn't achieve much, what does is using finer nozzles at 25cm spacing at 50cm boom height, double coverage.

You will get less drift at the 30cm height. There's a paper on this thread somewhere (search for "56cm" AND "drift" and you'll find it). That gives an advantage for the lower height of roughly 56% less drift from the lower boom height (compared to 50cm). That's well worth having IMO and and big part of why we went for this sprayer. Just does not make sense to me not to use it at this lower height.

Also, on coverage, I too thought that about the finer spray, but for most applications it isn't the case. In fact, on balance, I'd say more of the research shows very slightly better coverage using coarse, very coarse and even ultra coarse droplet sizes.

The key realisation for me was that to the eye 4 little blobs spread out with say area 1 mm2 each look like better coverage than one blob with area 4 mm2 (especially when air filled AI droplets can then burst and spread), whereas for a lot of sprays there is no difference between these two. (The only exception to this is very small targets such as flea beetle and 1 leaf black-grass.) Obviously the latter will come from something like an AI nozzle whereas the former will will come from something like a FF. This is a very important point because the consequences of the two different nozzles are very different wrt drift and pesticide loss to the outside environment.

So, to lift a key quote from one of the abstracts below: "Results from this study show that an applicator can select a coarser droplet size classification without observable loss in coverage, while greatly reducing the drift potential of the application." This is a greatly underappreciated finding and I misunderstood it until I did this reading.

https://www.sciencedirect.com/science/article/pii/S0261219415301666
www.sciencedirect.com/science/article/pii/S0261219416301909

 

[Buggerallbandwidth]

This thread has migrated to a very interesting subject and deserves its own thread really. I stumbled on it by accident.
25cm spacing dictates you should not use 110 degree nozzles which achieve a double overlap at 50 cm spacing and 50 cm boom height. An 80 degree nozzle at 50 cm spacing would need to be run at a 60cm boom height for double overlap. So for 25cm nozzle spacing to get double overlap at a 30cm boom height you have to use an 80 degree nozzle. Yes?
Or am I just very confused?
Some on here saying they use 110 degree nozzles at 25cm spacing and 30cm boom height - surely that will lead to uneven application of pesticides ?
Anyone remember their geometry lessons ?

 

[Banana Bar]

Use Guardian lilac 025's at 25cm for some herbicides and all ear wash, angled forward backwards alternatively, coverage is excellent at 200l/ha. Though high water volumes for these specific applications no need to go to 80 degrees. True 50cm boom height is good enough, if too windy then shouldn't be spraying at 30 cm.

You must crawl along with 025 at 200lt

 

[Db880]

You must crawl along with 025 at 200lt

Wouldn’t have thought to as an 025 at 25cm is the equivalent of an 05 at 50cm so would still have very decent forward speed.

 

[Clive]

This thread has migrated to a very interesting subject and deserves its own thread really. I stumbled on it by accident.
25cm spacing dictates you should not use 110 degree nozzles which achieve a double overlap at 50 cm spacing and 50 cm boom height. An 80 degree nozzle at 50 cm spacing would need to be run at a 60cm boom height for double overlap. So for 25cm nozzle spacing to get double overlap at a 30cm boom height you have to use an 80 degree nozzle. Yes?
Or am I just very confused?
Some on here saying they use 110 degree nozzles at 25cm spacing and 30cm boom height - surely that will lead to uneven application of pesticides ?
Anyone remember their geometry lessons ?

Basically yes

Lower boom height needs to 80deg jets to maintain correct overlap

There was not much choice of 80’s if you also wanted AI but that seems to have changed

 

[fudge]

Er don’t 110 degree nozzles give double over lap at a height of 25cm if spaced @ 25cm. I don’t really think it is possible to tell the difference between a boom height of 25cm and 30cm. Unless one is spraying flat rolled ground the target varies too greatly. For example I pride myself on growing very even wheat but actual spray targets, leaf 1, flag leaf and ear all have a depth of at least 15 cm. other crops are more variable still.

Some of the comments on here read like Mr Horsch’s sales patter rather than practical spraying experience.

 

[Brisel]

You must crawl along with 025 at 200lt

At 50cm nozzle spacing, yes. I do 12 kph at 100 l/ha on 50cm spacing at 3 bar so 200 l/ha at 25cm spacing is about right.

 

[Banana Bar]

Wouldn’t have thought to as an 025 at 25cm is the equivalent of an 05 at 50cm so would still have very decent forward speed.

I do believe I’m wrong. Makes perfect sense as you say.

 

[Feldspar]

Anyone know if I put a higher number in the box marked d whether this means the booms switch off slower or quicker as one heads into a headland. Think I may have it the wrong way round and the German translation isn't great.

 

[Db880]

Anyone know if I put a higher number in the box marked d whether this means the booms switch off slower or quicker as one heads into a headland. Think I may have it the wrong way round and the German translation isn't great.
View attachment 836171

It depends what operating terminal you are using, if you using touch terminal from Horsch, yes adjust here. A smaller number should help to cover any misses when going into the headland. A larger number will make it worse. As it is the amount of time that it actually takes for the nozzle to turn off. Normally these don’t need to be adjusted because they are calculated values. If you have problems with section control normally it is down to the machine measurements that are running over the iso.

Please tell me what terminal your using to control the machine. If you want do this in a PM. If not contact the guys at Horsch or your dealer, it’s what they are there for......