Fruit Position on Tree Canopy Affects Fruit Quality Traits in ‘Sanguinelli’ Blood Oranges

Abstract

In modern orchard systems, the tree canopy is designed to ensure homogeneity in fruit quality. However, even in those crops there are some variables that affect the fruit maturation process and fruit quality properties. The aim of this work was to determine if canopy layer (upper vs. lower), fruit shoot position (grouped vs. individual) and orientation (west vs. east) affect fruit quality attributes of ‘Sanguinelli’ blood oranges. Thus, different quality traits, such as weight, internal colour (IC), external colour (EC), total soluble solids (TSS), titratable acidity (TA) and maturity index (MI) were determined for this purpose. Results showed that fruit weight, internal colour, TA and MI were influenced by the number of fruits per shoot. In this sense, the highest values of weight, IC and MI were found in the grouped fruits, while the highest values in TA were in the individual fruits. Regarding the EC and TSS, they were strongly related to the canopy layer, since the highest values were found in fruit located at the upper parts of the canopy. On the contrary, the orientation did not have a significant effect on fruit quality properties. Therefore, consistent differences in quality traits of ‘Sanguinelli’ blood oranges fruits were observed depending on canopy layer and number of fruits per shoot.