ABSTRACT

The tractor-drawn single row ginger rhizome harvester was the designed, fabricated and its performance was evaluated in terms of effective field capacity, field efficiency, and percentage rhizome damage. It consists of two main units; the rectangular support component and the digging component. The rectangular support measures 900 mm by 700 mm provided the support of which the digger and the three-point linkage are attached. The digging component comprises a V-shaped digger blade with a length of 670 mm, a width of 50 mm, and a thickness of 5 mm.  The harvester was operated at forward speeds of 0.63 m/s, 0.8 m/s, and 1.8 m/s, rake angles of 16o and 32o, and depth of cut of 8 cm, 10 cm, and 12 cm in a split-split plot design. The harvester's draught was measured using an electronic dynamometer; an average draught force and power were evaluated and recorded as 0.856 kN and 1.19 kW, respectively. Other machine parameters were field capacity, theoretical field capacity, and efficiency obtained ranges from 0.0225-0.0655 ha/h, 0.318-0.90 ha/h, and 68-95%, respectively. Hence, a split-split plot was used to analyse the interaction of speed, depth of cut, and rake angle.  Analysis of Variance showed significant effects on harvesting ginger rhizomes, and no significant effects were demonstrated in other parameters at p ≤ 0.05.  Response surface was used to obtain the optimum value of speed as 1.3 m/s and depth of cut of 8cm at rake angle either 16o or 32o. Finally, the ginger harvester offered minimal bruise to the ginger rhizomes of approximately 0.5%, thus easy to operate, reliable, and recommended for farmers' use.