You are here: News > Insights

You are viewing 1 of your 2 free articles

You’ll need to join us by becoming a member to gain more access.
Already a Member?

Login Join us now

Spreaders and Sprayers: Testing your granular applicator


Machinery testing requirements have been extended for this year, with granular applicators included for the first time. Jane Carley looks at what is involved for granular herbicide applicators and how to ensure your machine meets the standard.

Twitter Facebook
Main Pic

All granular herbicide applicators must be tested regularly.

Since the introduction of new legislation to comply with the sustainable use directive (SUD) on November 26, 2016, granular applicators used for herbicide applications must be tested if they are five years old or over, with the test repeated every six years.

In addition, granular applicators used for nematicides must be tested annually. You will also need a separate output test if the same machine is also used to apply slug pellets. More frequent tests may be required to comply with crop assurance protocols.

"You need to provide a suitable test site – preferably in an area intended for the application of granules if using live product"



Operator qualification requirements for spreading herbicide granules is PA4G.


Many test centres will send an examiner out to your farm to test the applicator, explains Mark Elder, NSTS manager for John Rhodes AS.

“While this is convenient, you need to provide a suitable test site – preferably in an area intended for the application of granules if using live product.

“Otherwise choose a clean, dry place out of the wind – you can use an empty barn in poor weather. Appropriate PPE must be worn – for live product this, includes boots, coveralls, gloves, face shield and dust mask/respirator.”

The examiner will not calibrate the machine as part of the test, which simply checks the evenness of output. The machine should be calibrated after the test, before using it and then regularly throughout the season.

You are required to collect granules which come out of the machine during testing and arrange safe disposal. This applies even if using dummy material as there may have been some residual granules in the machine from previous use.

Overall condition

The examiner will look at the overall condition and safety of the machine – are all guards drive shafts or pulleys in place, intact and secure?

Hoppers and lids must be correctly fitted and seals intact, and boom latches able hold them in place securely for transport.

The metering unit drive system must be in good working condition and appropriate to the requirements of the operation.


Ensure metering rotors are made of an appropriate material, sound and not blocked– the examiner will remove them from the machine, and strip and check them. If any are damaged, the full set must be changed so sets are not mixed.

Access and cleanliness

Safe operator access for filling hoppers which cannot be loaded from the ground must be provided – either with steps and a handrail or suitable step ladder.

A copy of the manufacturer’s instruction manual should be available, and where live product is used, a copy of the pesticide label.

Mr Elder says: “The applicator must also be in a clean and dry condition with no traces of the product. While there may still be a few granules inside, if the examiner cannot see the rotors, he will not test it until you have thoroughly cleaned it out.”

Never pressure wash a granular applicator – clean off with a brush or vacuum to avoid water ingress to the metering and application system.

Boom and pipework

Where applicators have a boom, the examiner will check it is straight from where it meets the centre frame in both planes.


If boom height adjustment and suspension are fitted they must be working correctly; the boom must also return to a level working position when it is pushed down. If break-backs are fitted, these must work correctly.

All pipework needs to be intact – check all hoses for leaks or damage and that the hose between the meter outlet and fish tails or deflector plates is smooth on the inside.


When in working position lookout for any tubes which are pinched or kinked.


Boom outlets should be evenly spaced and in good condition – the examiner will check there is no mouldy product or soil in them.

“If a fishtail [outlet] is damaged this would not ‘fail’ the machine, but replacement would be advised. Outlet alignment and deflection angle must be in accordance with manufacturer’s specification as it can affect the application pattern – a patternation test may be carried out,” says Mr Elder.

The outlets must be at the correct height above the intended application surface.

The examiner will also check the airflow at each outlet for evenness across the boom.

Output test

This is a key element of the test, so it is worth running when preparing the machine, says Mr Elder.

“Run the machine for a minimum of 100g per metering unit, using calibration trays, granules collected in a bucket or a bag for air-assisted machines. Output should be within 10 per cent of the tolerance stipulated by the manufacturer of the product.

“If you are not happy with the results or it is clear the air is not getting down to the outlets, it is worth having the machine serviced to remedy any faults,” says Mr Elder.

Pneumatic system

Check the fan is in good condition without bearing wear or fouling and that it is running in the correct direction.


Also check for leaks at working pressure, especially around the transfer point from the hopper to the metering system and to the air transfer pipes and outlets.

Finally, ensure the venturi has no wet material stuck in it which could affect the flow of air/granules.

Twitter Facebook
Rating (0 vote/s)
Post a Comment
To see comments and join in the conversation please log in.

Related sections

Agronomy and crop protection

Agronomy and crop protection

News, features and analysis of the agronomy challenges growers and agronomists are encountering in modern day crop protection.
Handy hints: practical advice, handy tips and Buyer's Guides

Handy hints: practical advice, handy tips and Buyer's Guides

Handy tips and advice from all sectors across agriculture.
Machinery: On-test and first drives

Machinery: On-test and first drives

From quads to Quadtracs, and everything in between, we test drive all the latest machinery and farm technology.

More Insights

On-test: Skoda’s seven seater ticks the 4x4 boxes

With the addition of a new seven-seat model, Skoda has expanded its 4x4 offering. Geoff Ashcroft put the firm’s Kodiaq to the test.

VIDEO: On-test: New Holland T5 put through its paces

Brimming with features, we test drive New Holland’s latest T5 Electro Command tractor series.

Arable Farming magazine's July 2017 digital edition

Don’t miss this month’s new look Arable Farming. Take a look at the digital edition today.

Chicory and plantain fight the drought

Plantain and chicory are often overlooked as forages for dairy and sheep. But their potential in boosting performance can have a significant impact on a unit’s bottom-line profitability. Farmers Guardian reports.

OSR clubroot threat on the increase - here's how to tackle it

More acidic soils, tighter rotations and a changing climate are just some of the reasons why clubroot is on the increase and spreading to new regions, according to new study. Abby Kellett reports.
FG Insight and FGInsight.com are trademarks of Briefing Media Ltd.
Farmers Guardian and FarmersGuardian.com are trademarks of Farmers Guardian Ltd, a subsidiary of Briefing Media Ltd.
All material published on FGInsight.com and FarmersGuardian.com is copyrighted © 2016 by Briefing Media Limited. All rights reserved.
RSS news feeds