`Durum wheat grain samples (n = 327) harvested during 1998 and 1999 in eigh
t different Italian agroclimatic areas and representative of the main Itali
an cultivars were analyzed. Image analysis of whole grains allowed five siz
e and shape descriptors (length of minor and major axes, perimeter, area, a
nd ellipsoidal volume) to be measured on 100 grains for each sample. By mul
tiple regression analysis, shape measures more valid to explain semolina yi
eld were identified. By combining these measures with test weight or 1,000-
seed weight, equations useful to predict semolina yield were developed.