Blueberry Chilling Model Dilemmas

Abstract

Several chilling models have been developed to estimate the chilling requirement for specific deciduous fruit crops and to predict the time of rest completion. While the early chilling models were developed primarily for deciduous fruit trees, others were developed subsequently for several other fruit-bearing plants, including blueberries ( Vacciniumsp.). Traditional chilling models for field-grown deciduous blueberries vary by genotype and location. However, as blueberry germplasm, cultural practices, and production systems evolve, different chilling models may be required to estimate chilling for these plants. Useful chilling models include a time of chilling inception, a temperature range where chilling is accumulated or negated with weighted values or other clearly defined calculations, and a phenological event when rest is considered completed within a specified period of time.