In the present study it was evaluated the aerial dispersion rate of Plasmopara viticola spores during 2005/06 and 2006/07 seasons and their relation with microclimate under covered and conventional cultivation of grapevine. A commercial vineyard of Moscato Giallo cultivar (Vitis vinifera L.) in Flores da Cunha, RS (29° 06'S, 51° 20'W, 541 m) was used. It comprised twelve rows of plants covered with a transparent plastic (raffia type - 160 µm) and five uncovered rows of plants, each row with 35m of length. The microclimate was evaluated, in terms of air temperature, air relative humidity, wind speed and pluvial precipitation above the canopy in both treatments. Two spore traps were installed in each treatment by using transparent tapes with gelvatol. Every week, the tapes were retrieved and mounted on slides for microscopy, randomly selected 20 days in each treatment and season, where the number of trapped spores was determined. The covered vineyard showed the highest amount of aerial dispersion of spores Plasmopara viticola. Regardless of the cultivation in the afternoon period, it was observed higher dispersion.
plasticulture; Vitis vinifera; disease management; fungal diseases; mildium
