Are the chilling temperatures the only climatic factor to overcome endo-dormancy in the temperate fruit trees? Which other climatic factors can affect the endo-dormancy and the effect of the chilling temperatures?

摘要

The endo-dormancy of buds is a characteristic physiological behavior of temperate plants. Endo-dormancy affects the growth and reproduction and its overcoming happens when the buds are exposed to useful chilling temperatures for a spell mainly. The accumulation of chilling temperatures is enough in the temperate zones; instead, there is a shortage in tropical and subtropical zones creating some setbacks for the commercial production of temperate fruit trees. The studies carried out in those zones demonstrated that some other climatic factors (sunshine, rain, fog, etc.) affect the endo-dormancy duration. The application of some cultural practices (e.g., shading) on the intensity of light (solar radiation) and the length of daylight (photoperiod), bathing and sprinkling shoots during the rest season can decrease the chilling requirement and advance the bud burst of temperate fruit trees. That has allowed the improvement of the growing and production of these fruit trees in tropical and subtropical zones particularly in the orchards placed at high altitude.