The purpose was to found out relevant variables and appropriate stages to early highlight significant genetic differences and effects of location in apricot. Quantitative growth and branching variables were studied in young grafted trees for 4 varieties in 3 locations of French growing area. In addition flowering resources were evaluated in the adult stage. The contrasting traits in vigour, size and form between adult trees of the 4 varieties were in agreement with the quantitative genetic differences recorded in early development. The low adaptability to Mediterranean climate of ‘Bergeron’ and ‘SEO’ resulted from different flowering behaviours. Also, unexpected differences between the Languedoc and Roussillon coastlines were recorded as regard the effects on flowering