Evaluation of Physical Properties of Maize and Pigeonpea Seeds for Seed Metering Mechanism

Abstract

Physical properties of seeds such as size, shape, bulk density, angle of repose and thousand seed mass are important design parameters for seed metering mechanism. Some of the physical properties of maize and pigeonpea seeds were determined as they are crucial factor for effective planting. The average values of length, width, thickness, geometric mean diameter, sphericity, bulk density, angle of repose and thousand seed mass of maize were found as 9.79 ± 0.33 mm, 8.03 ± 0.39 mm, 4.16 ± 0.32 mm, 6.89 ± 0.26 mm, 0.70 ± 0.03, 0.76 ± 0.01 g/cm3, 26.54° ± 0.60 and 223.91 ± 1.50 g respectively at moisture content of 10.90  ± 0.03% on dry basis while similar values for pigeonpea were 6.94 ± 0.31 mm, 5.61 ± 0.30 mm, 4.99 ± 0.27 mm, 5.79 ± 0.19 mm, 0.82 ± 0.03, 0.82 ± 0.01 g/cm3,  28.36° ± 0.44 and 136.64 ± 1.56 g respectively at moisture content of 11.24  ± 0.04% on dry basis. The determined properties were found relevant to the design of the components of planter. The size of cell and delivery tube were relevant to linear dimensions while bulk density and angle of repose were relevant to hopper design.