Flower removal time and fruit quality in cactus pear (Opuntia ficus-indica Mill.)

To understand the influence of "scozzolatura", or first flower removal, and, in particular, of flower removal time on fruit quality, a two-year experiment was performed in a commercial orchard of 'Gialla' cactus pear cultivar. Plants were 30 years old, unwatered and trimmed to bush shape. The orchard was located at Sarroch, in Southern Sardinia. Three groups of ten plants each were arranged, where early flowers were removed on the Ist of June, on the 20th of June and on the 10th of July. Ten plants were left undisturbed to provide control fruit. Flower removal delayed fruit ripening by about two, three and five months respectively for the first, second and third date of pruning. The following quality parameters were observed in control and late-ripening fruit: mean weight and volume; pulp and peel color; fruit firmness; peel thickness and relative weight of peel, pulp and seeds; pulp acid, sugar and total soluble solid content. The latest ripening fruit showed greater weight and firmness, and relative weight of seeds, but also lower fruit color, sugar and total soluble solid content compared to control fruit. Fruit yielded after the first and second blossom removal appeared to have the best quality characters.