VARIABILITY IN INFLORESCENCES IN VARIOUS VARIETY TYPES OF COMMON SUNFLOWER ( HELIANTHUS ANNUUS L.)

In the fields of the Przybroda Experimental Station of the August Cieszkowski Agri- cultural University of Pozna& selected features of inflorescences were compared in two hybrid varieties and one population variety of common sunflower. The scope of biometric measurements included the diameter of the flower head and its sterile part, the degree of inclination of the inflo- rescence and the thickness of the receptacle. On the basis of the obtained data the area of the flower head and its sterile part were calculated together with their percentage. Moreover, changes were investigated in the diameter of the inflorescence during its maturing. The population sun- flower variety produced the smallest flower heads, which were characterized by the biggest sterile part. All the flower head features analyzed in this variety were characterized by the highest values of standard deviation, but the coefficient of variation was frequently the highest in hybrids. Indi- vidual variation had the highest effect on all the analyzed characters of the inflorescence.