Phenological stages and fruit development in the Mexican plum ecotype 'Cuernavaquena' (Spondias purpurea L.)

摘要

Introduction - Spondias purpurea L. or Mexican plum is a fruit tree of Mesoamerican origin with significant potential as a large-scale agricultural crop, yet little information about its phenology and fruit development is currently available. Materials and methods - The phenological stages that occurred during a one-year cycle of fruit production were assessed in trees of the ecotype 'Cuernavaquena', along with changes in fruit dimensions, weight (fruit, peel, pulp, and seed), color (L*, C*, and h), and total content of sugars, phenols, and carotenoids. Results and discussion - The following six phenological stages were easily distinguished: 1) flowering; 2) fruit setting; 3) fruit development; 4) leaf emergence; 5) fruit ripening; and 6) leaf abscission. The fruits presented a double sigmoidal growth curve typical of drupes. During their development, the epicarp color changed from an opaque green (L*= 41.1, C*= 22.6, h= 109.1) to a light and vivid yellow (L*= 45.6, C*= 39.2, h= 87.5), while sugars increased to 79.9 mg g(-1) f.w. by harvest time. Total phenols in the mesocarp and epicarp decreased to 266.7 and 641.8 mu g g(-1) f.w. respectively, favoring an overall reduction in astringency. In these same tissues, carotenoids increased to 50.8 and 27.0 mu g g(-1) f.w. respectively, facilitating the establishment of a visual harvest index. Conclusion - The identification of distinct phenological stages along with the growth curve will permit better agronomic management of S. purpurea L. Additionally, the chemical composition of its fruits suggests they can supply significant amounts of energy, as well as molecules with a high antioxidant capacity, to the human diet.