2014 Volume 60 Issue 3 Pages 206-212
Seed singulation accuracy tests of the device described in the first report (2014) were carried out to determine the effects of the angles of inclination of the discs, seed-releasing speed (times/s), and seed aspect ratio (length/thickness) of dent corn (Zea mays L.) seeds. Moreover, to verify the suitability of the device for guiding released seeds to the ground, we performed release accuracy tests with a trial structure constructed by assembling the device and a slit. The results of the seed singulation accuracy tests showed that the single-seed-separation ratio was approximately 98% when the angles of inclination of the discs ranged from 42° to 58°. Seed-releasing speeds in the range of 4-12 times/s were found to have a negligible effect on seed singulation. Furthermore, the seed singulation ratio decreased as the seed aspect ratio increased. The release accuracy test results showed that when the seed-releasing speed was set to 4-12 times/s and the tractor speed and seed spacing were assumed to be 2.16 m/s and 18cm, respectively, the standard deviation of the seed spacing that calculated by using the time taken and the horizontal distance covered by a seed before it reaches the ground level was approximately 1.5-3cm. The tested apparatus was suggested to be suitable for practical use.
