you can access  article available on http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2638997/

and 

http://e-collection.library.ethz.ch/eserv/eth:6746/eth-6746-02.pdf

This study will support your question. Find this paper from google search 

The Physiology of Chilling Temperature Requirements for Dormancy Release and Bud-break in Temperate Fruit Trees grown underMild Winter Tropical Climate: A review on Global Perspectives

Abstract

Until recently, the cultivation of temperate fruits in tropics and subtropics were subject to temperature variations in winter months that can seriously hampered the production and would result in prolonged dormancy, protracted flowering and delayed defoliation. The period of adequate low temperatures is insufficient to properly satisfy the natural cold or chilling requirements of these crops.Up to date, there are many validated methods for the characterization of the number of chill-hours (CH) to test the physiological behavior of temperate fruits trees grown under tropical and sub-tropical conditions, but most of these models used showed varying results as it was posed by high temperature fluctuation.All the existing modeling approaches are purely empirical, and there is a limitation in their application from one regionto the other, indicatingthat their accuracy differs substantially. This requires model comparisons for specific location, i.e. by using more than one model to avoid the potential mis­leading in application and for better estimation of chill hours without biases.Currently, very little information is available on the chill unit requirements, chill models, varieties and species of temperate fruits grown in the tropics and sub-tropics in respectof the changing climate. Winter chill must be studied more than many other weather dependent processes because the historical trends in chill hour requirements has generally declined  across all locations in the globe as indicated by many research reports from different regions. Thus, changes in global climate can have a profound effect on timing of dormancy requirement and its  release  for most of the temperate crops grown under tropical conditionsarestill remains as a research gap and subject of debate for many researchers involved in the present climate change scenarios.This review also indicates us in identifying chill thresholds from the literature, identifying the impacts of climate change in chilling requirements of different regions and providing information on some climate change adaptation strategies.

I suggest you contact Professor Dan Gerling of Tel Aviv University.