Determination of some operating parameters in chickpea sowing with pneumatic single seed planter.

In this study, the effect of different seed drop heights, sowing rates and forward speeds on horizontal seed distribution uniformity and single seed metering unit performance in sowing of chickpea seeds with single seed planter was investigated in laboratory conditions. In order to determine the horizontal seed distribution, the distances between successive seeds and ordinary deviation amounts of the seeds were measured on the sticky band. Multiple index, miss index and feed index were calculated to determine the single seed unit performance. The experiments carried out in seed drop heights of 100, 200 and 300 mm, sowing rates of 4, 6 and 12 kg da-1 and and forward speed of 0.5, 1.0, 1.5 m s-1. The experimental set up was randomized factorial design in three repetitions. According to the results, the height of seed drop, sowing rate and the increase of the forward speed had a negative effect on sowing quality and single seed metering unit performance. In all sowing rates, the seed spacing and deviation from row increased as seed drop height and forward speed increased. In terms of horizontal seed distribution uniformity, the best seed drop height 100 mm and the forward speed were 0.5 m s-1. Increased sowing rate worsened seed distribution uniformity. The best sowing rate values were obtained in 4 kg da-1 depending on horizontal seed distribution. Increased seed drop height and forward speed increased the miss and multiple indexes, while decreased the quality of feed index. The highest quality of feed index was obtained from 100 mm seed drop height, 4 kg da-1 sowing rate and 0.5 m s-1 forward speed as 90.46%, 92.49% and 92.86%, respectively. The lowest values obtained from 300 mm seed drop height, 12 kg da-1 sowing rate and 1.5 m s-1 forward speed as 84.81%, 78.41% and 82.82%, respectively. As a result, it was determined that low of seed drop height and forward speed and use of seed spacing greater than 50 mm improved seed distribution uniformity of the horizontal in single seed sowing of chickpea seeds.