Frequency and intensity of pruning young 'Valencia' orange trees in orchards under organic culture system/Frequencia e intensidade de poda em pomar jovem de laranjeiras 'Valencia' sob manejo organico

This study evaluated the influence of frequency and intensity of pruning on young orchards, with organic management system, on the yield and fruit quality of 'Valencia' oranges. The trees were budded on Poncirus trifoliata rootstock and implanted in August, 2001, in Montenegro-RS. The pruning tested was: A--control, without pruning; B--annual pruning of 15%; C--biennial pruning of 15%; D--biennial pruning of 30% and E--three-year 30% pruning of the canopy volume. The experiment had a randomized complete-block design, with four-trees plots and four replications. The total fruit mass production was registered and the average weight fruit in the crops 2006, 2007 and 2008 was determined. The fruit quality, total soluble solids (TSS), total acids concentration (TTA) and ratio (TSS/TTA) were assessed. In orchards with fewer than seven years old, the pruning does not change the cumulative yield for three seasons, the fruit quality and its physical-chemical properties. The frequencies and intensities of pruning reduce the yield in the year after pruning.