Moisture Dependent Selected Engineering Properties of Deenanath Seeds in Relation to Development of Processing Machinery

Propagation of grasses through seeds is important in view of vigour and germination. Various grasses as Pennisetum pedicellatum Trin., Cenchrus ciliaris L., Chrysopogan fulvus have lower vigour and germination, due to which they need specific operations as defluffing, separation of true seeds, cleaning and grading by specific machines. In designing a machine for a specific use, physical properties and their behaviour with moisture play an important role. A study was conducted to assess the effect of moisture content at five levels [6.88 - 19.23 %, (d.b.)] on selected physical properties of defluffed Deenanath grass seed. The length, width, thickness, arithmetic mean diameter, and geometric mean diameter of defluffed Deenanath seed increased from 2.30 mm to 2.56 mm, 0.71 mm to 0.96 mm, 0.47 mm to 0.63 mm, 1.16 mm to 1.38 mm, and 0.90 mm to 1.15 mm, respectively, with increase in moisture content 6.88 % to 19.23 %. Bulk density, true density, and porosity decreased from 652.16 kg.m^-3 to 585.78 kg.m^-3, 852.63 kg.m^-3 to 792.71 kg.m^-3, and 25.62 % to 24.97 %, respectively, with increase in moisture content from 6.88 % to 19.23 per cent. The aspect ratio, sphericity, surface area, volume, and thousand-seed mass of the seed were in the range of 30.91 - 37.51 %, 0.39 - 0.45, 2.58 - 3.23 mm², 3.71 - 4.97 mm³, and 0.480 - 0.523 g, respectively. Linear relationships with correlation coefficients higher than 0.90 were observed for the physical properties over the experimental range of moisture content.