干旱区生态环境知识资源中心

Fruit growth and ripening, and the effect on fruit quality of various storage temperatures, were studied with Hylocereus undatus and Hylocereus polyrhizus plants growing in Beer-Sheva (Israeli Negev desert) under greenhouse conditions. Fruit growth was sigmoidal with a strong decline in growth rate after the onset of peel colour change. The first change in peel colour was recorded 24-25 days after anthesis in H. undatus and 26-27 days in H. polyrhizus. In both species, the peel turned fully red 4-5 days after the first colour change (mean temperature for the study period was 26.6 +/- 2.1 degrees C). The slow growth phase was characterised by a decrease in the proportion of peel and concomitant increase in that of pulp, increase in the concentration of soluble solids and soluble sugars and a decline in firmness and the concentration of starch and mucilage. The surge in acidity prior to colour change indicated the beginning of the ripening processes. For H. polyrhizus, which has a red-violet pulp, the increase in pulp pigment paralleled the development of peel colour. Fruits were non-climacteric, and when harvested at close to full colour, they retained market quality for at least 2 weeks at 14 degrees C or 1 week at 20 degrees C. Storage at 6 degrees C is not recommended, because transfer from that temperature to room conditions caused fruits to lose their firmness and flavour rapidly. (C) 1999 Elsevier Science B.V. All rights reserved.