CHARACTERISATION AND INFLUENCE OF FLORAL ABORTION IN FRENCH APRICOT CROP AREA

In apricot, abortion of floral primordium through tissue necrosis (commonly called ‘floral anomalies’) can occur early and intensively from ‘dormant’ stage or later with necrosis limited to pistil at flowering stage. Under the climatic conditions of French Mediterranean growing area, some varieties are unfruitful or irregular due to a high susceptibility to floral abortion. Nevertheless, in the French breeding program focused on disease resistance and fruit quality, some susceptible varieties are necessarily used as genetic resource. Therefore investigations on floral abortion were performed during six successive years in Mediterranean regions more particularly. Results recorded from a large genetic variability in various climatic conditions allowed to characterise floral abortion regarding different features: main factors involved, relationship with tree architecture, occurrence of abortion during floral development, influence on annual and biennal fruit bearing.