Estimation of chilling requirement and comparison of models for prediction of end-dormancy completion among Prunus species
The chilling requirement were monitored in apricot (Prunus armeniaca), mume (P. mume), peach (P. persica), plum (P. salicina), and plumcot (P. salicina × armeniaca) during three consecutive years (2014-16) in Wanju, Republic of Korea. One year old shoots were incubated at 25°C of temperature and 16 h of light photoperiod condition. The breaking of endo-dormancy was considered when 50% of flower buds protrude after 14 days. Three different chilling requirement models, chilling hours model, Utah model, and dynamic model, were adapted and compared. The end-dormancy breaking of Prunus species were ranged from mid-December to mid-February. Nanko mume showed the lowest chilling requirement with 600 chilling hour (CH), 500 chilling unit (CU), and 30 chilling portion (CP), and the endo-dormancy was broken around December 14th. Soomee peach showed the highest chilling requirement with 2000 CH, 1050 CU, and 70 CP, and the endo-dormancy was broken around February 15th. The full bloom date and chilling hours model (R2=0.69**), Utah model (R2=0.72**), and dynamic model (R2=0.72**) showed significant positive correlation. The Utah model and dynamic model showed lower variation between years than chilling hours model in this study.
Kwon, J.H., Nam, E.Y., Yun, S.K. and Kim, S.J. (2020). Estimation of chilling requirement and comparison of models for prediction of end-dormancy completion among Prunus species. Acta Hortic. 1290, 231-236
flowering date, mume, apricot, plum, peach