Evaluation of a Planter Equipped with Vertical Rotor Cell-Type Metering Mechanism for Sowing of Pearl Millet

Millets, particularly pearl millet (Pennisetum glaucum), are important crops in arid and semi-arid regions due to their drought tolerance and nutritional value. Efficient planting methods are key to optimizing yields and minimizing resource usage. The adoption of planters, especially those incorporating advanced mechanisms like vertical rotors with cell-type metering systems, is increasing as these improve seed distribution accuracy and reduce labour-intensive manual sowing. A tractor-operated multi-crop planter with a vertical rotor and cell-type metering mechanism was evaluated for its performance in pearl millet sowing. The planter, designed for precision planting, had a working width of 2.25 m and maintained a row to row spacing of 450 mm. Key engineering properties of pearl millet seeds, such as size, shape, geometric mean diameter, moisture content, and angle of repose, were examined to ensure compatibility with the metering mechanism. The planter was tested in both laboratory and field conditions at various forward speeds (2 to 4 km h-1), and using different furrow openers (12 mm inverted T-type, 30 mm and 55 mm shovel types). Results showed better performance at lower speeds (2.0 to 2.5 km h-1), with a consistent seed placement depth of about 20 mm, ensuring uniform crop emergence. The quality feed index (QFI) reached up to 94.80%, while the missing index (MI) and multiple index (MU) remained low, reflecting minimal errors in seed distribution. The planter's fuel consumption ranged from 2.62 to 3.51 l h-1, and field capacity varied between 0.33 and 0.50 ha h-1. The best (optimal) performance was observed at 2.5 km h-1 with a 30 mm shovel-type furrow opener, achieving a sowing depth of 20.4 mm, QFI of 94.16%, field capacity of 0.40 ha h-1, and fuel consumption of 2.97 l h-1. The operational cost was Rs. 705 per hour or Rs. 1765 per hectare, making it economically viable for small to medium-scale farmers.