Evaluation of three seed distribution mechanisms

Abstract

Three seed distribution mechanisms, conic, spiral, and helical shaped, assembled on three manual seeders were evaluated with regard to sowing density (number of seeds per meter), distribution uniformity (acceptable spacing), slippage and forward velocity. Maize, soybeen, and wheat seeds were used in the evaluation tests. The percentage of acceptable spacing (0.5 - 1.5 nominal spacing) varied from 32.8%, for the spiral mechanism, to 54.8%, for the conic mechanism, both using maize seed. The soybeen sowing density varied from 454,167 to 491,667, for a target density of 450,000 seeds/ha; with maize, it varied from 55,833 to 70,000, for a target density of 60,000 seeds/ha; and with wheat, it varied from 3,920,000 to 4,111,100, for a target density of 3,770,000 seeds/ha. The driven wheel slippage varied from 0.3%, for the spiral type, to 0.5% for the helical and conic shaped.