The vine plant and grapes may be affected by a series of diseases of which the most well-known are grey rot, downy and powdery mildew, which are mostly prevented by chemical applications. The awareness of secondary effects of pesticide use on the environment and human health is driving the research towards the use of alternative and environmentally-friendly products for plant disease managements. The proposal WINELAND aims at developing and testing a new natural product, mainly composed by tannins and smectites, to improve the control of common, key plant diseases, without any detrimental effect on the microbial biodiversity in conventional and organic vineyards. The attention will be devoted to these natural derived substances which can legally be added during wine-making process, and which showed antimicrobial activity in some preliminary studies. At first, the experimental strategy will be outlined to evaluate, in vitro and in vivo, the antimicrobial activity of the compounds against the three major pathogens affecting grapevines, i.e. Botritys cinerea, Plasmopara viticola and Erysiphe necator. Concurrently, their influence on indigenous grape berry microorganisms will be evaluated by in vitro trials using as targets moulds, yeasts and bacteria of technological significance in grape and wine production. Then, open-field grapevines treatments with the designed product will be carried out in conventional and organic vineyards. The impact of this product on the microorganisms present on the vines samples will be determined by culture-dependent and culture-independent (metagenomics) approaches. Finally, the effect of the new treatment in the vineyards on the microbial composition, the must fermentation kinetics and the quality of the final wine will be investigated. The natural product optimized in this project will be, then, marketed by the Company, answering the growing global demands requiring healthy products and eco-compatible strategies.