Effect of alternative fungicides and inoculation strategy on yeast biodiversity and dynamics from the vineyard to the winery

Fungi and oomycetes found in vineyards cause diseases such as powdery and downy mildew. Consequently,
conventional and alternative agronomical practices are widely used prior to harvest to protect grapes. Alternative
products are considered more eco-friendly and environmentally sustainable in comparison to conventional
chemical products. However, the effect of these alternative products on yeast ecology, from the vineyard to the
winery, is poorly understood. This study compared the effect of alternative and conventional chemical antifungal
compounds (copper and sulphur based) on grapes' mycobiota in the vineyard and during subsequent winery
fermentation using culture-dependent and -independent approaches. Culture-dependent data indicated a
treatment-dependent effect on the load and diversity of yeast populations on grapes. It was found that the
population of Hanseniaspora uvarum was higher on grapes previously treated with laminarin and copper,
compared to the other levels registered on grapes previously treated with the rest of antifungal products tested in
this study (including the untreated and conventional treatment controls). Concerning, wine quality, the chemical
composition was not correlated to the application of antifungal treatment in the vineyard. Understanding the
effect of different antifungal products on grape and wine microbial communities may help in setting up
guidelines for wine grape production. These guidelines, can be used to guarantee quality in the pursuit of a
sustainable competitive advantage in the market."