effect of mechanical pruning on the yield and quality of ‘fortune’ mandarins

Abstract

This work compares mechanical pruning followed up by hand pruning versus manual pruning in the case of ‘Fortune’ mandarins. Yield and fruit quality were measured over a three-year period. Two mechanical pruning intensities were tested, these intensities being measured as the width of the row middles left free after mechanical pruning. Although there were differences in biomass and diameter of the branches that were cut, no differences were observed between the two mechanical pruning intensities in terms of yield or fruit quality. In all pruning treatments, fruit size reached the highest category. The pruning treatments consisted in: (i) hand pruning every year, (ii) mechanical pruning followed up by hand pruning every year, and (iii) alternating the two previous methods over the years studied. On analysing the accumulated fruit production of the three years, it can be observed that there were no significant differences in yield when mechanical pruning was alternated with hand pruning over the years. When only mechanical pruning was used for the three years, however, a 22% reduction in yield was observed with respect to the treatment involving hand pruning alone. From the economic point of view, mechanical pruning shortened the time needed to complete the follow-up hand pruning by 13% with respect to just hand pruning, but this reduction in labour does not offset the cost of the mechanical equipment.