A Conceptual Model Of Changes In Deep Supercooling of Dormant Sweet Cherry Flower Buds

Abstract

Abstract A conceptual model of sweet cherry (Prunus avium L.) flower-bud deep supercooling during dormancy is presented. The extent of deep supercooling exhibited by the flower buds is expressed as the temperature of the median low-temperature exotherm (LTE50). The model calculates the LTE50 hourly, using air temperature, chill unit accumulation, and the previously calculated LTE50 in the decision pathways. An initial and updated LTE50 are determined experimentally by differential thermal analysis (DTA) in order to start the model at the beginning of the dormant season and to update it at periodic intervals. The model has been tested and validated. This model will overcome the delay in direct measurement and provide orchardists with a method of estimating critical flower-bud cold-hardiness temperatures for use in freeze-protection decisions.