Some citrus species show irregular production over the years. Besides the irregular crop yield, alternate bearing may affect the fruit quality, a characteristic that is increasingly valued by the citrus market. The aim of the work was to evaluate the effect of crop load on fruit quality of 'Valência' orange trees. The experiment was carried out under field conditions with 'Valência' orange scions grafted on 'Cleópatra' mandarin rootstocks. In January 2007, half of the plants were defruited, while the other half remained intact. Plants that had their fruit removed showed in September 2007 more intense flowering, and therefore a high fruit load (HL, 752 fruits/tree) in 2008, compared to intact plants showed low fruit load (LL, 317 fruits/tree). The fruits harvested in December 2008 were analyzed considering weight, soluble solids, titratable acidity, peel thickness, juice percentage, number of seeds and peel color. In the next crop, in 2009, the evaluations of physical and chemical characteristics of fruits were carried out in the same trees but during four moments between fruit development and harvest in November 2009. Fruit harvest in 2008 had different individual weight with values of 172 and 158 g for LL and HL plants, respectively. The soluble solids, titratable acidity, percentage of juice, peel thickness and technological index was similar between treatments in 2008 and 2009. However as fruit production in HL plants was 2.2 times higher than in LL plants in 2008 (AC: 2,9 boxes/plant and BC: 1,3 boxes/plant), total soluble solids produced per plant was also higher. Crop load did not affect the sugar content (glucose, fructose and sucrose) in juice and skin color during fruit development. Although it reduced the fruit weight, the difference in crop load observed in 'Valencia' orange had no influence on fruit quality when considered the citrus industry as fruit destination.
Citrus sinensis; carbohydrates; orange; alternate bearing
