Determining the Optimal Parameters of a Precise Vacuum-Cylinder Metering Device for Sowing of Iranian Lentil Seed

The main objective of this study is to investigate the performance of cylinder-type vacuum precision seeder and to find its optimum performance point. Mean seed spacing, Miss and Multiple indices of lentil seed were used to evaluate the optimum performance of metering device. In this study, the effect of vacuum pressure (30, 50 and 80 mbar), seed hole diameter (2, 3 and 4 mm) and conveyor speed (2, 4 and 6 km/h) were investigated on the metering device performance by using grease belt made and all assessments were conducted in a completely randomized design. Results showed that the optimum performance point of seed whole diameter, vacuum pressure and speed were determined as 3 mm, 50 mbar and 2 km/h. In this optimum point, the Miss Index, Multiple index and mean seed spacing were obtained as 6.55%, 8.82% and 6.18 cm, respectively. Maximum deviation of actual and nominal mean seed spacing was obtained at the seed hole diameter of 2 mm and grease belt speed of 6 km/h. The acceptable performance of metering device was obtained in the low speed of grease belt, medium seed hole diameter and medium vacuum pressure.