Abstract:

Chilling requirement for bud dormancy and caloric requirement for blooming of 12 Peach varieties grown in southwestern Zhejiang were studied. With the use of Utah model, results showed that: among the 12 peach varieties, those with low chilling requirement (550-650 cu) were Amygdalus persica 'Chunmi’, Prunus persica 'Chaohong’, P. persica var. nectarine 'Zhongyoutao11, P. persica var. nectarine 'Zhongyoutao7’and Prunus persica var. nectarine 'Zhongyoutao4’, those with middle chilling requirement (650-800 cu) were P. persica var. nectarine. 'Liyou5’, P. persica 'Cangfangzaosheng’, P. persica 'Yanhong’, P. persica var. nectarine. 'Liyou3’and P. persica 'Zaofengwang’, and those with high chilling requirement (900~950 cu) were P. persica 'Xinchuanzhongdao’and P. persica 'Chiyue’. Large differences of caloric requirements for blooming were found among different varieties grown in the same area, but small differences were found within the same variety in different years. A two-year consecutive experiment showed: the low caloric-requirement (400-500 d·℃) varieties were P. persica 'Chiyue’and P. persica var. nectarine 'Liyou3’, the middle caloric-requirement (500-600 d·℃) varieties were P. persica 'Xinchuanzhongdao’, A. persica 'Chunmi’, P. persica var. nectarine 'Liyou 5’, P. persica var. nectarine 'Zhongyoutao4’and P. persica var. nectarine 'Zhongyoutao7’, and the higher caloric-requirement varieties (600-700 d·℃) were P. persica 'Zaofengwang’, P. persica 'Cangfangzaosheng’, P. persica 'Yanhong’and P. persica var. nectarine 'Zhongyoutao11’, and the highest caloric-requirement varieties which need 700-800 d·℃ were P. persica 'Chaohong’. There was a significantly negative correlation in power function between chilling requirement and caloric requirement of the 12 peach varieties.

Key words: Peach, bud, chilling requirement, caloric requirement