Sustainable, Chemical-free Nematode Control in Senegal

After persistent loss of yield due to nematodes, and a desire to move towards a more sustainable agriculture, these growers in Senegal looked to the Aqua4D system after having seen its successes in other countries. In particular, they wanted to analyze the efficacy of Aqua4D in reducing the population of Meloidogyne nematodes, whose attacks their green beans are particularly sensitive to.

As the main goal was to go to explore chemical-free alternatives to nematicides, they decided on a direct comparative study: comparing Aqua4D and the Rugby 20EC nematicide literally side by side.

On 1 hectare of land, two plots were to be treated by Rugby, and two plots treated using the Aqua4D system. On the last count prior to the study, both Meloidogyne and non-parasitic nematodes had been prevalent in both the soil and the root area – between 100 and 200 per 100g of soil, in fact.

These nematodes affect root development and hence productivity and yields of green beans. So the parameters to be measured were root mass, nematodes in the soil & root area, and net weight of yields after the studied period.

The Science

The Aqua4D system does not eliminate nematodes in an invasive way, as chemical nematicides do. There are absolutely no chemicals used here, and nothing is added to the irrigation water. Instead, Aqua4D uses an innovative treatment to rearrange the structure of water molecules.

Crucial fact: the nematodes are not killed or harmed – they’re distracted away from the roots, meaning they can then no longer harm the roots or lay eggs there. And healthy root growth means healthy plants, which ultimately means higher yields.

This change to the physical structure of water increases absorption in soil, but significantly in this case, the same treatment also has the effect of repelling nematodes away from the root area (more info here).

What effect would the Senegal grower see on his nematode problem and his plants?

The Method

 – Rugby 20EC nematicide (containing the cadusaphos pesticide) applied in a 24L total dosage across 25 days.

– Aqua-4D device installed as part of the existing irrigation system, and used throughout normal irrigation processes.

– Plots included both the Paulista and Processor variety of green beans

The Results

Several variables were measured mid-cycle and at the conclusion. As the plots were side by side, it ensured that the only difference was the application of Rugby nematicide / Aqua4D respectively.

The end results (available here as PDF, in French) were beyond the wildest expectations of the grower. It showed a conclusive victory for the Aqua4D system, which came out top in almost every aspect.

Firstly, and most importantly in this case, was the consistently steady decrease in the Meloidogyne nematode population in the soil, from 30 per 100g of soil to just 7 per 100g at the end, significantly less than in the Rugby plot.

Crucially, the root mass was much higher in the Aqua4D treated plots – indeed, on average almost double the mass. Why? Mainly because the root system was able to develop healthily, strongly, and with more hairy roots, due to the reduced presence of nematodes.

Meanwhile, in the root area – where most nematodes are normally found – the results showed a clear difference, with significantly less parasitic nematodes present in the Aqua4D plot at all stages (7489 at conclusion, compared to 34,367 in the Rugby plot)

Of course, when the roots are not under attack they can flourish to their full potential, resulting in healthier plants and – most significantly from the grower’s perspective – higher net yields. Indeed, measured in kilograms per hectare, the Paulista variety in particular yielded a massive 2202.15 from the Aqua4D treated plot, compared with 1263.97 from the chemically-treated plot.


The Aqua4D system came out on top against the Rugby nematicide in reducing the parasitic nematode populations in both roots and soil, which had a knock-on effect on the average root mass and consequently the final crop yields.

While the results show that the chemical nematicide had a quick impact, its efficacy over time fell away, and by the end of the cycle the Aqua4D system had steadily increased its gains. This is in line with the fact that Aqua4D gently nudges the nematodes away from the root area, so that they do not lay eggs and hence the population steadily decreases.

Moreover, a crucial difference from a practical perspective was also that the Aqua4D system was installed “plug-and-play” as part of the existing irrigation system. In contrast, the less effective chemical nematicide needed to be applied on three different occasions, requiring more product and more labor on the part of the grower.

So in Senegal, as in Switzerland, as in Argentina, and many other countries, the Aqua4D system has once again come out on top compared to invasive and unsustainable chemical nematicides, paving the way to efficient and sustainable agriculture.

  • Senegal
  • Nematodes

  • Water savings

After Aqua4D treatment: nematode-free hairy roots