Qualidade de frutos de pitaya em fun??o da época de poliniza??o, da fonte de pólen e da colora??o da cobertura

摘要

The pitaya (Hylocereus undatus) is a cactaceae vegetative propagated, that results in little or no variability in commercial plantations. Due to several studies shown that the specie is auto or relatively self-incompatible, this study was conducted with the objective to check the efficiency of self pollination in red pitaya and utilizing pollen from H. polyrhizus and Selenicereus setaceus, and the effect of time and the plastic screen cover color, on fruit quality. The research was realized at the Faculdade de Ciências Agrárias e Veterinárias - UNESP, Jaboticabal Campus, Brazil, in a completely randomized design, factorial 3 X 2 X 2 (three pollen sources X two environment for cultivation - under plastic screen, black and white, with 50% of shade X two periods) and four replicates for each pollen source, in each of the coverage. The flowers were emasculated in two periods (March and April) and hand pollinated. The variables evaluated were percentage of fruit set and physical and chemical characteristics (length, diameter, total weight, flesh weight, skin weight, percentage of flesh pulp, peel thickness, pH value, total soluble solids content (oBrix), ascorbic acid content, titratable acidity, ST/AT ratio) and the period from pollination to fruit ripening (days). There was no fruit set in auto-pollinated flowers, although cross-pollinated flowers with H. polyrhizus and S. setaceus pollen the fruit set was 100%. It can be concluded that is necessary mixing plants of H. undatus with different species (H. polyrhizus or S. setaceus) in order to occur fruit set, and the use of H. polyrhizus pollen as donor provides heavier fruits and with less acidity. The environmental conditions occurring during fruit development at the evaluated period, influenced fruit quality.