This study aimed to the influence of two techniques, early defoliation and cluster thinning, in the agronomic behavior of Aragonez, its effects on yield, health and quality of grapes. The trial was conducted in 2013, on a vineyard of Quinta do Pinto, in Lisbon wine region, Portugal. The treatments studied were defoliation at flowering (ED), defoliation at the end of pea size and cluster thinning at verasion (D&T) and a non-defoliated and non-thinned treatment was used as a control. The early defoliation consisted of the removal of 6 basal leaves from all shoots one week before flowering while D&T consisted of a defoliation of about 3 basal leaves only in the east side of the canopy at the end of pea size and bunch thinning of all second order clusters at veraison. The early leaf removal caused significant changes in the structure of canopy, by reducing leaf area, the exposed leaf surface and increased cluster exposure, thus improving the microclimate covered. This improvement was reflected in the decrease of botrytis. This treatment also caused a decrease of 57 % in yield compared to the control, however no significant differences in the quality of the grapes to harvest.

Mestrado em Viticultura e Enologia - Instituto Superior de Agronomia / Faculdade de Ciências. Universidade do Porto