THE BEHAVIOR OF VEGETABLE SEED PICK-UP USING A VACUUM SEEDMETERING UNIT (VSMU)

This study aimed to evaluate the performance of a vacuum seed-metering unit (VSMU) developed for sowing vegetable seeds in trays under different vacuum pressures. Laboratory experiments were conducted using three seed types with markedly different physical and geometric properties: pepper, Armenian cucumber, and okra. Metering performance was evaluated in terms of the accuracy, miss, and multiple indices. The results showed that seed physical and geometric properties affected the optimal vacuum pressure, which was 1.52, 7.5, and 8.5 kPa for pepper, Armenian cucumber, and okra seeds, respectively. The corresponding accuracy indices were 93.54%, 91.25%, and 96.04%. Seeds with a relatively large mass, such as okra seeds, or low sphericity, such as Armenian cucumber seeds, required higher vacuum pressures than the flat, approximately circular pepper seeds. The developed VSMU therefore demonstrated its ability to handle seeds with diverse physical and geometric characteristics and achieve accurate seed metering.