The protected cultivation of grapes is an alternative to reduce the incidence of fungal diseases in regions with excess rainfall. The use of plastic covering on vine planting rows produces changes in the microclimate around the plant, due mainly to the absence of freely available water on leaves and berries. These changes hinder the development of fungal diseases, such as bunch rot - currently one of the biggest challenges in disease control in traditional grape growing regions like Serra Gaúcha - and reduce fungicide use. However, powdery mildew, whose incidence under high relative humidity conditions is usually low, must be closely monitored in protected cultivation. Also, fungicides must be used with caution as plastic covering reduces the incidence of ultraviolet radiation and rainfall on clusters, thereby increasing the residual effect of fungicides. The higher accumulation of fungicide on grapes directly affects their in natura consumption and compromises yeast fermentation during the winemaking process. In general, plastic covering is efficient in controlling fungal diseases and in reducing fungicide use, but it must be regarded as a new cultivation system as it requires distinct disease control compared to conventional cultivation. The used plastic covering must be regarded as crop residues, demanding specific precautions against environmental contamination.
plasticulture; grapevine; freely available water; fungal diseases; residues