STUDIES ON APPLE BRUISING .1. ESTIMATION OF INCIDENCE AND SUSCEPTIBILITY DIFFERENCES IN THE BRUISING OF 3 APPLE CULTIVARS

Bruising in ''Aroma'', ''Cox's Orange Pippin'' and ''Ingrid Marie'' ap ples grown in a Swedish research orchard were studied during two seaso ns-1992, 1993. Incidence was recorded by dropping fruits from 0, 5, 10 , 15, 25 and 30 cm. Bruising increased with increasing drop heights, a nd dropping from higher than 10 cm caused more large bruise areas. The diameter of some bruise areas increased during storage for 2 months. Aroma was the more sensitive cultivar and Cox's Orange Pippin was the more resistive against bruising. In order to compare bruise quantifyin g methods, we studied number, diameter, weight and volume of bruise. W e found that the bruise weight parameter ((bruise weight/fruit weight) x 100) was the most accurate method owing to the correspondence betwe en this parameter and impact energy.