Leaf bud endodormancy release in peach trees: evaluation of temperature models in temperate and tropical climates

Abstract

A biological test (‘single node cuttings’ test) was used to study the endodormancy dynamics of the leaf buds of three peach tree varieties in tropical and temperate climates over 3 years. Results showed evolution in the growth capacities of the leaf buds throughout endodormancy in both climates and it was thus possible to determine dates of endodormancy release. With these dates and hourly temperature data, the chilling requirements of the varieties were calculated by different temperature models reported in the literature. All these models proved inaccurate: for each variety, the computed chilling requirement shifted according to the orchard location and year of study. Possible reasons for their inaccuracy are reviewed and discussed.