Sormac investigates new solutions in the fight against aphids

The phasing out of plant protection products for aphid control presents a growing challenge for both growers and vegetable processors. Aphids not only cause damage during cultivation but also lead to quality issues during processing. That is why, at its laboratory in Venlo, Sormac – together with Vertify – is researching various mechanical and filtration techniques to remove aphids effectively and completely without the use of chemicals. 

To ensure all research is reliable and reproducible, Sormac has developed a standardised counting method, which allows the presence of aphids to be measured objectively and comparably. 

Ban on aphid control products

Within the European Union, plant protection products for aphid control have not been available since 30 October 2024, and their use will not be permitted from 30 October 2025. Their authorisation was withdrawn due to negative effects on beneficial insects and bees, threatening biodiversity and sustainability goals. 
In the United Kingdom and other countries outside the EU, these products are still permitted for the time-being, but reassessments are underway in those countries too.

Why aphids are becoming a growing problem

As chemical control agents are phased out, aphids are increasingly being found during quality inspections, both on the produce and in the washing water.

Their rapid lifecycle makes aphids particularly difficult to control: within just seven days, an egg develops into a nymph which, at temperatures above 10°C, becomes an adult aphid in approximately seven to ten days. This can occur within the usual shelf-life period, even inside the packaging. Nymphs moult several times, leaving behind pale skins on the produce. Both adult aphids and nymphs have a piercing-sucking mouthpart (rostrum/stylet) which allows them to feed on plant sap. They use this mouthpart to latch onto the crop, making removal difficult. 

Standardised counting method for objective measurement

The changing situation calls for a universal counting method that makes the effect of processing steps reliable and reproducible. Sormac has developed a standardised guideline for this purpose.

With this method, the presence of aphids is expressed as the number of aphids per 100 grams of produce, measured on full lettuce heads. To obtain a representative picture of reduction throughout the process, samples are taken at the start, middle, and end of each production run. 

Want to know more about the counting method? Request the guideline here.

Sormac researches effective solutions for aphid reduction

In addition to developing the counting method, Sormac is investigating several techniques to remove aphids as completely as possible.

1. Flotation washers
Research shows that 90% of aphids can be removed using flotation washers with turbulence, such as the Sormac Spiral Washer SW and the Sormac Lettuce Washer PULSTAR. A combination of water flow, air injection, and gentle mechanical movement ensures a high removal rate. 

2. Effect of agitation, washing and spraying
Mechanical agitation, strong water movement, and targeted spray patterns increase the likelihood that aphids and nymphs detach from the produce.

3. Additional washing phase and supplementary techniques
Introducing a second washing phase, possibly combined with a flycatcher or a final spray installation, have a clear added benefit.

4. Filtration and water management
Proper filtration of washing water is crucial to quickly and completely separate aphids, shed skins, and organic material. This reduces contamination and prevents secondary cross-contamination.

Sormac is currently optimising these techniques further to improve removal efficiency.

Working together for clean, safe produce

Changing European legislation is accelerating the demand for sustainable, mechanical solutions. Thanks to in-depth expertise in washing, drying, and inspection, Sormac contributes to a future in which aphids are removed hygienically and effectively without reliance on chemical pesticides.

In addition to internal R&D, Sormac partners with major players in the sector and participates in government initiatives focused on sustainable aphid control in vegetable processing. The counting method forms the foundation: a clear, uniform baseline to clearly define the problem and develop technologies that are demonstrably effective. 

Want to know more?

If you have questions about aphid removal research, the technologies Sormac is developing for cleaner and more sustainable processing, or would like to receive the counting method, please contact one of our specialists.