Changes in primary and secondary growth as influenced by crop load in ‘Fantasmet’® apricot trees

SummaryThe effect of crop load on the growth dynamics of individual shoots was analysed in apricot trees in the third growing season, comparing their development at two initial locations along the bearing branch. Growth dynamics were observed throughout the growing season, from April to August, and took into account both primary growth (i.e..number of expanded leaves) and secondary growth (i.e. basal diameter increment). Crop load influenced primary growth rhythmicity and more precisely growth resumption within the growing season. The length of the growing period and the number of expanded leaves were more signi®cantly reduced on shoots originated from a proximal position along the branch than in a distal position. Thus, crop load enhanced the acrotonic distribution of branching. The allometric relationship between the basal diameter and the number of expanded leaves per shoot was not dependent upon shoot type, location or crop load treatment. Arguments are provided supporting the hypothesis that cambial ...