Harnessing biocontrol: Natural solutions for Downy Mildew management in northwestern Spanish vineyards

Balancing sustainability and productivity: Striving for sustainable vineyard fertilisation

Galicia, situated in an area of Spain with particularly favorable climatic conditions, is prone to attacks by the Plasmopara viticola fungus, commonly known as downy mildew. This fungus poses a severe threat to vineyards each year, causing damage to shoots, leaves, and grapes, thereby diminishing both the quality and quantity of the harvest. Consequently, winegrowers are compelled to apply numerous treatments using conventional products, resulting in environmental damage that adversely affects both the vineyard and the soil used for viticulture.

In this trial, alongside implementing rational vineyard management practices concerning canopy control, we conducted tests using various bioproducts over three growing seasons. These tests aimed to assess the efficacy of these bioproducts in combating downy mildew compared to conventional chemical treatments. We adjusted our approach each year based on the results obtained.

While the initial trial outcomes did not meet our expectations, in 2023, we observed a promising response from the vines against downy mildew when using one of the biocontrol products, in contrast to those treated with conventional chemicals. Moreover, this year marked one of the most aggressive in terms of fungal attacks, with early onset and prolonged activity into the summer months. Our weekly monitoring revealed that utilising the biocontrol product until at least the flowering stage resulted in no greater incidence of mildew compared to vines treated with conventional methods.

Though this positive outcome was only observed in the final year of the trial, and further experimentation is necessary to draw reliable conclusions, these findings are encouraging. They suggest that even in challenging growing seasons such as this, it is possible to significantly reduce the reliance on conventional treatments without sacrificing the quality or productivity of the vineyard.