Phenological characterization and temperature requirements of Annona squamosa L. in the Brazilian semiarid region.

The phenological growth stages of various species of monocotyledonous and dicotyledonous plants can be uniformly coded using the Biologische Bundesanstalt, Bundessortenamt, und Chemische Industrie (BBCH) scale. The aim of the present study was to determine the duration of different phenological stages and the temperature requirements of the sugar-apple, Annona squamosa, during two crop cycles in the semiarid region of Brazil. Phenological stages were divided into eight of ten possible principal stages: (0) bud development, (1) leaf development, (3) shoot/branch development, (5) inflorescence emergence, (6) flowering, (7) fruit development, (8) fruit maturity and (9) senescence and the beginning of dormancy. The phenological cycle of the sugar-apple from having closed leaf buds to the fruit ripening stage lasted 149 and 164 days with temperature requirements of 1684.5 and 1786.7 degree days (DD) for the first and second crop cycles, respectively. The results provided important information that will inform the correct timing for crop management practices.