• NEIKER is investigating the possibility of alternating natural products with chemicals to control mildew and promote more sustainable viticulture.

 

Mildew, a disease that affects the green parts of the vine, such as leaves, young shoots and bunches, represents one of the main challenges for the Basque wine sector. The combination of abundant rainfall and high humidity levels in the Basque Country favours its appearance and spread each season, forcing winegrowers to apply frequent treatments and adjust their management practices to avoid losses in production and grape quality.

With the aim of offering new tools to combat this disease, NEIKER began to study the use of biostimulants and biofertilisers, natural products that can supplement vine nutrition and improve their ability to respond to stressful situations.

To test their effectiveness, trials were initially conducted under controlled conditions, which allowed the plants’ response to mildew to be evaluated without the influence of external factors. These tests showed that some of these products could limit the spread of the fungus and improve the vine’s defence capacity.

Based on these findings, the treatments were applied in commercial vineyards to study their behaviour under real growing conditions, where the effectiveness of the biostimulants proved to be more variable. ‘In the vineyard, elements come into play that cannot always be controlled, such as rain or heat, which can degrade or wash away the treatments,’ explains Ana Díez, a researcher in the Department of Plant Production and Protection at NEIKER.

These observations led the centre to develop a combined strategy designed to optimise mildew control and progressively reduce the use of chemical fungicides.

Specifically, the strategy consists of alternating applications of fungicides, which act directly on the fungus, with biostimulant products, which strengthen the plant and improve its natural resistance. The planning of each treatment must be adjusted to the vegetative cycle of the vine and the climatic conditions of each season, so that the products are applied only when necessary and in the appropriate dose.

‘The idea is to apply biostimulants at stages where they can strengthen the plant’s natural defences, while fungicides cover the moments of greatest risk of infection. This maintains crop protection and progressively reduces the use of chemicals,’ says the researcher.

 

Impact on sustainability

This strategy also has implications for the sustainability and economy of the vineyard. Reducing chemical applications decreases the presence of toxic substances in the soil and water, preserves microfauna and can reduce residues in the food chain.

In addition, it allows the wine sector to access markets that value sustainability criteria and facilitates the transition to organic production. In the context of the Basque Country’s Designations of Origin, such as Txakoli and Rioja Alavesa, these practices reinforce the image of agricultural sustainability and allow wine consumers to be informed of the sector’s alignment with green policies and environmental awareness.

In order to bring this knowledge to the sector, the centre is planning to organise workshops with visits to commercial vineyard plots, where technicians and winegrowers will be able to observe at firsthand how the combinations of treatments work and how they are integrated into the daily management of the crop.

‘This experience connects the results obtained in the laboratory and on commercial plots with everyday practice, facilitating the incorporation of these tools into the usual management of vineyards and promoting more sustainable and efficient management,’ concludes Díez.