Spray-drift reduction in Europe

Fruit growers are subject to increasingly strict drift-reduction regulations. What are their options for compliance? By Anna Mouton.

“We need plant-protection products to control insects and diseases, but in Europe, we feel a lot of pressure from the government and society,” said Dr Marcel Wenneker. “So, spray-drift reduction is mandatory in all Dutch orchards.”

Wenneker is a senior crop-protection researcher at Wageningen University and Research in the Netherlands. He has worked on spray-drift control for more than a decade.

“In the Netherlands, we do all our spraying with axial fan and crossflow sprayers,” he said. “In the old days, we used excessive airflow and fine droplets, which caused a lot of drift.”

But the old days are over. Public concerns about drinking-water contamination, human exposure, and environmental damage are driving regulatory changes with direct impacts on growers, as Wenneker outlined at the 2026 Hortgro Technical Symposium.

The regulatory framework

Spray-drift reduction doesn’t only affect growers. When applying for a crop-protection product registration, companies must demonstrate that spray drift doesn’t jeopardise surface water, bystanders, residents, non-target organisms, or neighbouring crops.

“I specifically mention neighbouring crops, because the aim in the Netherlands is that 15%–30% of production should be organic,” explained Wenneker. “If chemical pesticides drift from an integrated field or orchard into an organic orchard, residues will cause a big problem.”

In Europe, spray drift from orchard, vineyard, and boom sprayers is measured according to a standard (ISO 22866:2005) that specifies field trial layouts, weather conditions, sampling protocols, tracers, and airborne and sediment drift measurements.

Drift is usually reported as downwind ground deposition, airborne spray concentration, and percentage drift relative to the applied dose.

“Within Europe, the standard is harmonised, but the implementation can differ between countries, mainly due to the crop-free zone,” said Wenneker. “In the Netherlands, we have a 3-metre crop-free zone because we try to use as much land as possible.”

In most European countries, sprayers and nozzles are classified into 50%, 75%, 90%, 95%, and 99% spray-reduction groups, mostly based on field trials. For example, in the Netherlands, these classifications are based on relative reductions compared to a reference sprayer.

Drift-reduction classes also influence pesticide labels and buffer zones.

Drift-reduction technologies

Recognised drift-reduction technologies in the European Union include air-inclusion and low-drift nozzles; tunnel, sensor-controlled, recycling, and shielded sprayers; crossflow air adjustment; reduced fan speed; and lower spray pressure.

“We have a list of 50 drift-reduction technologies that are approved in the Netherlands,” said Wenneker. “In many cases, you have to combine mitigation measures, especially if you want to achieve 95% or 99% drift reduction.”

He described how drift-reduction technologies are assessed in the field. The candidate reduction measure is compared with a reference sprayer. Similar to the standards for determining sprayer performance, trials are conducted in accordance with ISO22866:2005.

The reference sprayer is a Munckhof crossflow sprayer with Albuz ATR Lilac hollow-cone nozzles at 7 bar spray pressure (producing very fine droplets). The reference application is performed at a PTO speed of 540 rpm, a forward speed of 6.4 kph, maximum air assistance of 21 metres per second, and a spray volume of 200 litres per hectare.

“We started a nozzle classification system for drift reduction because we know it’s easy to control drift with a coarse droplet,” said Wenneker. “Every fruit grower can use low-drift nozzles, and they can be mounted on nearly every sprayer, so it’s a cheap way to control drift.”

Extensive laboratory testing showed that nozzles can be classified by the volume fraction of droplets smaller than 100 microns, with droplet size correlating with spray drift in field trials.

“It took us about 15 years to convince growers that the biological efficacy is as good when applying coarse droplets as when applying fine droplets,” commented Wenneker. “We did numerous trials, and we can even achieve the same efficacy with 200–300-micron droplets.”

However, nozzles alone will only reduce drift by 90%–95%. To further limit spray drift, growers can, for example, mount air-injector (flat-spray) nozzles on three-row sprayers, thereby reducing drift by almost 97%.

Drift reduction in the Netherlands

The Netherlands has extremely stringent requirements for drift reduction. Regulations currently mandate 75% drift reduction in all orchards, 90% reduction along waterways, and up to 99% reduction for some pesticides.

To reduce drift, sprayers are also evolving technologically, for example, by measuring and adjusting their output based on wind speed and direction, or by incorporating LiDAR (Light Detection and Ranging, a laser-based remote sensing method) for gap detection.

“The problem is that every sprayer manufacturer wants to have 99% drift reduction,” said Wenneker. “Every test to get their sprayers approved costs about EUR50 000, so it’s difficult for them to get a return on investment.”

More advanced, approved sprayers are expensive and potentially more complicated for growers to operate (as though calibrating spray applications isn’t already complicated enough).

Nonetheless, spray-drift reduction is here to stay. “If growers do not comply, then they will no longer have products available to protect their crops,” said Wenneker.

Furthermore, non-compliant European growers could face penalties, and subsidies and certification schemes may be impacted.

Wenneker believes that precision applications are the future. As sensors, software, and variable-rate applicators become mainstream, it’s possible to envision a day when autonomous sprayers patrol orchards, identify pests and diseases, and target spot treatments only where needed.

Meanwhile, his team’s research can help South African growers. “If the regulations become stricter in South Africa, contact us,” he offered. “Take advantage of all the work we’ve done, and let’s see what the easiest way is for you to comply.”

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Watch this presentation on the Hortgro YouTube channel.