Spray application manual
31 January 2025
Test Nested Component
THIS IS JUST FOR TESTING - please ignore.
Trying to work out how we set up equations.
Thanks, Tiff.
It may seem obvious, but it is important to establish if you actually need a new sprayer before planning the purchase – it may be possible to refurbish an existing sprayer.
Unless there are major structural or mechanical issues with the sprayer, particularly when upgrading a trailing rig, it may be worth considering if various components can be replaced or improved to match the list of features you require.
| Speed (kilometres per hour) X |
Distance travelled (metres) x 3.6 |
| Time taken (in seconds) |
Wheel extensions on a John Deere tractor
It is useful to determine if the chassis and suspension will support any of the following:
a change to the tyre centres to match other equipment;
an increase to the tank size to increase the area sprayed per load (carefully consider the impact on weight and balance, as well as the tyres required);
if the boom is able to be extended or a new, wider boom can be fitted (will the current frame support a wider boom); and
if the current boom centres will support an upgrade to the boom stability and height control systems, or if they can be modified to support these.
Always check whether the sprayer or tractor hydraulics and current sprayer’s plumbing system can support the increased flow rates that will be required if larger tanks, wider booms, higher application volumes or higher spraying speeds are being considered, or if an auxillary pump is required for agitation.
Consider whether a major refurbishment of the pump, the plumbing system and the rate controller will provide increased functionality, such as improved section control or boom recirculation to reduce wastage and over-sprays.
If considering an upgrade, carefully compare the expected increase in hectares per hour of any change to the sprayer against the increase in hectares per hour of spraying that could be achieved if the mixing could be done in the paddock with improved mixing and transfer systems. Alternatively you may compare the cost of doing both against the cost of a new spray rig. Therefore when you do decide to replace the spray rig, you will still have the mixing and transfer systems in place to maximise the productivity of a new spray rig.
A self-propelled Case sprayer fitted with the AIM Command® pulse width modulation system
Retrofitting optical spot spray technology to older booms is now feasible (provided boom stability and height can be ensured). It is often common for growers to seek a wider boom and larger tank capacity where farm size has increased e.g. more land has been purchased. However it may be feasible to retrofit the older sprayer with a smaller tank size as an optical spot sprayer, and thus significantly increasing both spraying capacity and flexibility.
Buying a sprayer part 2
24 January 2025What to consider before buying a sprayer - part 2. Another video from GRDC's Spray Application GROWNOTES™series.
Bill Gordon: I'm here with David Gooden, a grower from Lockhart, and we're just going to have a quick chat about some of the decisions he went through when purchasing a new spray rig. So, David, with this machine, what are some of the things you considered when you were buying it, and what were some of the most important factors for you?
David Gooden: Well, the key decision was trying to buy something for the future. We wanted something with a bit of ground clearance so we could do something later in-crop. We wanted something that would give us the ability to apply high water rates, have different rates over a range of speeds, and over a range of droplet sizes, and finally, good service and backup. We wanted to make sure we had someone who was able to do that.
Bill Gordon: So the spray system that you went with on this machine, what's it fitted with?
David Gooden: It's fitted with 3TS rapid-fire recirculation. We spaced our nozzles at 25 centimeters spacing to allow better coverage. The important thing with rapid-fire recirculation is that it allows us to apply chemicals over a large spread range and with different water rates. It also allows us to recirculate our chemical before we get to the field, so we're not having to charge up the lines before we start operating, before we start a paddock.
Bill Gordon: Any other functions or features on it that, when you were weighing up your decisions, you thought, ""Oh, that's a good idea, I like that""?
David Gooden: Fuel use was a consideration, overall fuel use. So the machine we've got is a two-wheel drive, direct-drive machine, automatic, so the fuel use is quite low. The consumption is low. We wanted good service and good backup, so we wanted to deal with someone who knows about the whole system and can fix the problems when they occur.
Bill Gordon: When you purchased this machine, how wide did you end up going with the boom?
David Gooden: It's a 41-meter boom, and it matches with our controlled traffic system, so in multiples of 13.5 meters. We have a little bit of overlap.
Bill Gordon: Do you think that's an important thing for other people to consider when they're buying machines, how that sort of fits into the farming system and all the other equipment?
David Gooden: Absolutely. When going to controlled traffic, matching the sprayer is an important part of matching machinery.
Bill Gordon: So with this machine, how long do you reckon you'll keep it before you change it?
David Gooden: Maybe six years, say three or four thousand hours roughly.
Bill Gordon: So it seems to me that you spent a lot of time doing research and doing a bit of homework before you actually bought this machine, David.
David Gooden: That's right, yeah. We put a lot of work into trying to come up with the system that suited our operation and our needs and requirements to make it more efficient and effective when we go out and spray.
Bill Gordon: I think the take-home message for all growers is to do your homework and a bit of research about what sort of machine is going to suit your farming system. Think about the factors, some of the things that David talked about, and obviously service, speed range, volume, and how it fits into the future—into the farming system. They're really important. So it means that the machine that suits David may not be the same machine that's suitable for your farm.
Things to consider when the purchase of a new sprayer is required
Even for a new sprayer, it may be useful to establish which components or options available on the sprayer at purchase are able to be upgraded at some time in the future. Compare the costs of optional components or upgrades on delivery, versus the cost of retrofits at a later date.
Consider the ‘whole of life’ costs of the sprayer: how much will it cost to own and operate the sprayer? Carefully analyse the running and service costs of the sprayer model you are considering by gathering as much information as possible from other operators and the machinery dealers. Also consider what the residual value of the machine will be at the end of the time you plan to own it.
Documenting the maintenance and services conducted, along with minimising the engine hours by mixing and filling near the site of application, will help to retain the sprayer’s value at changeover.
As with any machinery, carefully consider the fixed and variable costs. It is a good idea to consult with your accountant regarding depreciation schedules and lease or finance options.