Physical Properties of Vetch Seed

The physical properties of vetch seed were evaluated as a function of moisture content. The average length, width and thickness were 5·19, 4·33 and 3·63 mm, respectively, at 10·57% dry basis (d.b.) moisture content. In the moisture range from 10·57 to 20·63% d.b., studies on rewetted vetch seed showed that the thousand seed mass increased from 55·47 to 59·03 g, the projected area from 23·52 to 29·05 mm2, the sphericity from 0·837 to 0·859, the true density from 1286·2 to 1369·9 kg m−3, the porosity from 33·08% to 39·68% and the terminal velocity from 9·94 to 10·33 m s−1. The static coefficient of friction of vetch seed increased the linearly against surfaces of four structural materials, namely, rubber (0·350–0·387), aluminium (0·319–0·367), stainless steel (0·202–0·328) and galvanised iron (0·312–0·361) as the moisture content increased from 10·57 to 20·63% d.b. The bulk density and the shelling resistance decreased from 860·8 to 826·2 kg m−3 and from 148·73 to 62·68 N, respectively, with an increase in moisture content from 10·57 to 20·63% d.b.