Sprayer and operator legislation explained

The challenge of successful spraying was set out by Tom Gartland of Syngenta at the recent Irish Tillage and Land Use Society workshop on new spraying legislation requirements.

Tom set the scene for the day when he stated that the objective of efficient spraying was to put more spray on the target while simultaneously minimising or preventing loss to the environment.

The nozzle lies at the heart of hydraulic spraying, Tom stated. Choice of nozzle must be influenced by the crop and what the target is in that crop. It takes more water to get good coverage on crops with big canopies, such as potatoes.

Different water volumes may be required for different tasks, such as pre-emerge herbicide, and nozzles are a primary water volume control mechanism. Just as there is no best water volume, neither is there a single best nozzle.

Over the years, spray application has drifted away from the hollow cone towards increasingly efficient fan jets which have been engineered to give better application efficiency and decreased risk of drift.

While Syngenta was instrumental in the development of the Amistar nozzle, many other similar nozzles have since been brought to the market and are popular with professional sprayer operators – the Defy and Guardian Air nozzles being just two examples.

While efficiency of spray application is the major objective, drift reduction has become increasingly important. Different nozzles are now designated as having either 75% or 90% drift reduction capacity.

But large drift reduction will generally mean bigger droplets and Tom said that this can affect the ability to hit the target. All decisions on nozzle choice are a compromise.

Water rate is also a factor in spray application and chemical delivery. This must be job-specific. Tom said that 100 to 130 litres/ha of water is adequate for most spray jobs on cereals, but others such as blight and some brassica sprays may need well in excess of 200 litres/ha.

A good rule of thumb is that the smaller the target you want to hit, the less water you should use, as you will have smaller nozzles and smaller droplets. With less water you have finer droplets to put more chemical on the target. But compromise may again be necessary in dense canopies.

Liquid pressure is another tool in the droplet size balance. Higher pressure makes smaller droplets, as the energy causes greater atomisation. But increased atomisation of the fluid increases the risk of drift, so a careful balance is needed.

Boom height above the crop is an important consideration here, Tom stated. Where a boom is carried at 0.8m above the crop versus the recommended 0.5m for a boom fitted with 110° fan nozzles, the risk of drift is four times higher.

Spray legislation

The EU has set limits for the maximum concentration of pesticides in water and these provide the background against which legislation is based.

Kenneth Conroy from the pesticide registration and control division (PRCD) of the Department of Agriculture told us that keeping pesticides out of water is important to ensure their continued availability in the market.

The Drinking Water Directive sets a maximum legal limit of 0.1 parts per billion in drinking water (one part per 10bn). This is not a health-based limit, but an arbitrary value set to ensure the virtual absence of pesticides in drinking water.

This is a very low limit, equivalent to one second in 317 years. It is highly sensitive and one foil seal contains enough pesticide to breach this limit along 30km of a typical stream with 1m width and 0.3m depth.

Pesticide levels in water are also set by the Water Framework Directive as environmental quality standards (EQS). These set maximum concentration limits for individual substances, but these are science-based to protect aquatic species and apply to all water bodies.

If products appear in drinking water, a review process could result in further restrictions in the product use or its removal from the market. So every effort must be made to prevent chemical getting into water.

Kenneth said that there are two main sources of contamination:

Problems at point sources are really a matter of better hygiene and methodology during filling and washing. Reducing diffuse losses are mainly about good spray practice and minimising spray drift.

The best starting point is to read the product label. The label is important because it specifies the distance needed between the application zone of each active and any water-carrying system – open drain or watercourse.

Every plant protection product has a fixed buffer zone to help prevent access to water. The size of the buffer (from one to 60m) reflects the potency of the specific active to aquatic organism. Products that are more potent have a bigger buffer zone.

Kenneth said that the Department put in place its national action plan for pesticides in 2013 and its purpose was to decrease the impact of pesticides on society. As part of this, staff at PRCD have developed the new STRIPE initiative, which is designed to decrease pesticide risk and exposure.

STRIPE effectively decreases the spray buffer distance to make full use of the field. Where a grower is using less than the full recommended rate of a product, its concentration in any drift will be lower and so reduced rates present less risk to water. Also, the use of nozzles with proven reduced drift capacity further decreases the risk of product moving to water bodies.

These two factors together – reduced rates and drift-reducing nozzles – form the basis of the STRIPE initiative to effectively minimise the buffer requirement.

This enables field margins beside water bodies to be sprayed much closer to the drain or river and thus minimise any problems that could emerge from there. The specific details of the initiative can be found on the Department's website.

For example, Frelizon has a 10m buffer requirement. But if used at half-rate, coupled with using 75% drift-reducing nozzles (Amistar nozzles), take this back to just 1m.

Where a product does not show a buffer requirement on its label, Kenneth stated that a minimum of 1m should be assumed for all products. Also, where there is a mix of products in the tank, the buffer requirement is set by the product with the highest buffer requirement.

While the flexibility provided by STRIPE applies to water bodies, it does not apply to safeguard zones near water abstraction points.

Sprayer testing

Under new pesticides legislation, all sprayers with a boom width of greater than 3m must be tested to a recognised standard by trained personnel.

Donal Lynch of PRCD explained that this is to ensure that spray application equipment be of a required standard to ensure maximum spray efficacy while protecting the environment.

All sprayers must be tested by November 2016 and every five years thereafter up to 2020. After that, the test must be repeated every three years. New sprayers must be tested after five years, but this may well decrease to three years also after 2020.

As of now, this legislation only applies to boom sprayers of greater than 3m. However, Donal stated that all other pesticide application equipment will need to be tested in time. This includes pellet applicators, foggers, seed dressers, smaller sprayers, etc. All new sprayers must meet these uniform standards.

Sprayers that pass the test will be given a sticker and a certificate. These will be sent to the sprayer owner, but both of these must go with this specific sprayer in the event of sale.

A lot of details of the sprayer are captured during the test, including the serial number, the number on the pump, etc. If a major item like the pump has to be replaced, the testing agent should be notified so that the certificate can be amended in case of inspection.

The sprayer

“It is important to have sprayers in proper working order. A sprayer must be capable of mixing and keeping the different actives in the tank in solution, be capable of safely transporting the spray solution and then apply it accurately and evenly with minimum drift,” said Dermot Forristal of Teagasc.

This applies to both simple and sophisticated sprayers.

The nozzle is the critical component and they must all be at the same height off the ground, be set at the same angle and be stable in motion – you must have a good boom.

Dermot stated that the test covers the PTO, pump, tank, pressure gauge, controls, boom and nozzles. All of these must be tested.

PTO: This is critical. The shaft and cover must be in good condition and the anti-rotation chains fitted. All sprayers must be fitted with a shaft support device, even if one was not fitted when new.

Pump: The pump must have sufficient capacity to apply the spray through the biggest nozzle while visibly agitating the spray liquid in the tank. It must be within 90% of the manufacturer's flow rate.

Tank: There must be no leaks. All tanks must have a basket strainer fitted (many don’t). There must be a vent in the lid for pressure compensation. A liquid level indicator must be fitted and be visible. There must be a way to empty the tank. The induction bowl must work if one is fitted.

Controls: The pressure gauge is critical. It must be at least 63mm in size and show at least 0.2 bar resolution (many don’t). This will be checked for accuracy. The controls must be reachable and they must be working. As well as section controls, there must be a single on/off switch for the full boom. Flow meters must be tested and be within 5% of the actual flow rate. Section controls must work and show minimal pressure drop when activated (<10%). There must be at least two filters – one in the pressure flow and one suction filter. Any other filters fitted must also work.

Boom: Must be in good physical condition with all stabilisers and adjustments working. It must be lockable in the transport position. Nozzle spacing and orientation must be uniform. Nozzles should not spray on any part of the sprayer (except possibly boom stabilisers). Booms that are greater than 10m in width need to have the nozzles protected. The liquid pressure drop from the main gauge to the end of the boom must be less than 10%.

Nozzles: All nozzles in a set must be identical and all sets fitted to a boom must be tested. They must be within 10% of their rated output. Where nozzle filters are fitted, the same ones must be fitted to all nozzles. The same anti-drip device must also be fitted across the full boom width and there must be no drips after five seconds of shut-off.

Operators

Donal Lynch reminded us that all professional users of sprayers must be registered with the Department by 26 November 2015 and they must have the necessary training to register.

Anyone applying pesticides will need a registration number after that date. Continuous professional education will also be required on an ongoing basis.

Donal said that there are currently 500 users registered and there are a further 170 pending. He also said that an estimated 14,000 people already have the required training from past courses with Teagasc. But you will have to enquire from Teagasc if you are on that list.

In all instances, it is the person who operates the sprayer and applies the plant protection products that must be registered.

It is not enough that an operator be supervised by a registered user.

A practical perspective

Spraying under these new requirements will bring additional challenges, but they are all fundamentally good, according to Philip Reck, a previous sprayer operator of the year award winner.

Having sprayers in good working condition will help sharpen the application accuracy across the sector and this is important if we are to maintain access to our plant protection products.

Philip manages eight crops, uses 64 different plant protection products and sprays about 20,000 acres annually for Walter Furlong Grain Ltd in Wexford. He acknowledges the importance of having the sprayer in perfect working order and also the benefit of continuous training to help make the best use of all plant protection products.

Philip uses RTK precision farming technology to add further accuracy to the self-propelled Bateman RB 35 sprayer, which is fitted with a 4,000-litre tank and 30m boom. The technology activates the 10-section boom to turn each section on and off on short ground. This control technology can also be used to force the sprayer to avoid specific areas such as buffer or abstraction zones. The wide boom is also fitted with a Norac boom height control system.

At the moment, he is recording spray details manually to computer, with the recommendations coming from an independent consultant. Philip hopes to convert to a cloud-based system in the near future and to have a pad in the cab to record all relevant information live.

Philip maximises the use of drift-reducing nozzles with the Amistar nozzle featuring heavily to combine low volume and low drift. He used the Twin Cap for head sprays to attempt to achieve both front and rear ear coverage. All nozzles have to be variable rate and capable of maintaining their spray pattern as pressure drops or increases with changes in forward speed.

Philip will use the new STRIPE initiative to minimise the buffer requirements along water systems.

Buyers versus users

During discussion, it was established that this legislation imposes no restriction on the purchase of a sprayer. However, only a registered professional user can subsequently operate a sprayer.

Also, one does not have to be registered as a professional user to purchase chemicals. However, since January 2014, all pesticide sales must be logged and Department inspectors can subsequently follow up on where, how and who actually applied these products.