A Comparative Study between Wild and Cultivated Varieties of Adlay Grains for Some Engineering Properties

: This study was carried out to complement the database of wild and cultivated Adlay grain varieties and to identify the similarities and differences between them. Results of the analyses determined that regarding the polar diameter (D p ), thickness (T), and coefficient of contact surface (C cs ), there were not any significant differences between wild and cultivated varieties (p>0.05); Otherwise there were significant differences on the properties of equatorial diameter (D e ), geometric mean diameter (D gm ), arithmetic mean diameter (D am ), frontal surface area (A fs ), transverse area A t ), sphericity (ø), shape index I s ), mass (M), volume (V), particle density (ρ p ), bulk density (ρ b ), and porosity (ε ) (p<0.05). In term of shape, the wild variety tended to be widened, while the cultivated variety tended to be lengthwise. Based on hardness and stickiness, the wild type was harder and stickier than the cultivated ones. The emptying angle of repose, filling angle of repose and the static friction of cultivated variety was relatively higher than that of the wild type. The mean total colour difference between the wild and cultivated variety was 6.952 ± 0.011.