Highbush blueberries need sufficient chilling exposure to induce bud break and flowering, which limits their cultivation in warm areas as well the profitability of protected greenhouses. Hydrogen cyanamide (H2CN2, HC), gibberellic acid (GA3), ethephon (CE), mineral oil (MO), potassium nitrate (KNO3) are often applied deciduous fruit trees advance set. In this study, experiments were conducted n...