Comportamento produtivo da videira 'Niagara Rosada' em diferentes sistemas de condu??o, com e sem cobertura plástica, durante as safras de inverno e de ver?o

摘要

The Niagara Rosada is the most important table grape cultivar for growers from Jundiaí region (S?o Paulo, Brazil). Currently, aiming to increase the grower benefit some technological alternatives have been recommended such as training system in a Y shape on replacement to unilateral single cordon with three vertical catch wires; application of off-season pruning that allows to obtain two harvests per year (summer and winter) and the use of plastic overhead cover to protect the vine's clusters against hailstorm and diseases occurrence. Therefore a field trial was carried out aiming to characterize the influence of the "Y" trellis system and the use of plastic overhead cover on yield and cluster size of 'Niagara Rosada' table grape. The obtained results during the growing seasons: summer (2008 and 2009) and winter (2009 and 2010) showed that the Y shaped system allows obtaining higher yields and larger size of clusters when compared to the vertical trellis system. The plastic overhead cover on the Y shaped system increased yield and cluster weight. It was also found that yield and cluster weight were higher for the summer growing season when compared to the winter crop.