Was studied the effects of three defoliation dates (FL - full bloom, BC – pepper corn size pepper corn sizepepper corn sizepepper corn size pepper corn sizepepper corn size pepper corn sizepepper corn sizepepper corn sizepepper corn size, P - veraison) and three intensities (ND – non-defoliation, 1L - defoliation on one side of the canopy and 2L - defoliation on both sides of the canopy) on leaf area, canopy structure and microclimate, bunch rot, yield, must and wine composition. The basal leaf removal was handmade and consisted on removing a strip of 35 to 40 cm height in the fruit zone. The trial was carried out in 2011 on a vineyard of Sauvignon variety, located at Quinta do Gradil, in the Lisbon wine region. The most intense defoliation (2L) in any date induce a significant reduction onto exposed surface area, leaf layer number and consequently an increase in porosity, clusters exposure and light interception at fruit zone compared to the non-defoliated vines (ND). These results induce a reduction of bunch rot incidence (except P). Related to ND, the most intense defoliation (2L) significantly reduced the yield, at all dates (except veraison), without changes on the must or wine composition. The wines from the leaf removal treatments (except FL2L and P1L) were preferred in the sensorial analysis, especially the BC2L and P2L wines.

Mestrado em Engenharia Agronómica - Hortofruticultura e Viticultura - Instituto Superior de Agronomia