Dormance et croissance des bourgeons du platane hybride (Platanus acerifolia) en milieu urbain

The purpose of this study is to analyse the physiology of Platanus acerifolia buds, especially latent buds that are exploited by urban prunings. Biological and biochemical tests have allowed us to observe the following: (i) The dormancy of the 1-year-old twig buds is weak and characterized, in November, by a mediobasitonic gradient of bud bursting ability. During the dormancy period, the latent buds have the same capacity to bud break as buds from the proximal part of 1-year-old twigs. The dormancy of the latent buds is weak but accentuated with bud ageing. (ii) The inhibition of the 1-year-old twig proximal buds is particularly detected during the dormancy period. Whatever the month, the latent buds are not able to develop unless the axis and the more distal buds above them are eliminated. (iii) The buds keep their intracellular properties (5,5′-dimethyloxazolidine-2,4-dione accumulation) if the axis above them is intact. (iv) The growth of the hybrid plane tree is characterized by a weak acrotony as wel...