Abstract:
In developing countries, most root crops are harvested by hand. Larger commercial producers may find a degree of mechanization an advantage, but the use of sophisticated harvesting machinery is most appropriate for industrial farming operations. In most circumstances, harvesting by hand, if done properly, will result in less damage to produce than will machine-harvesting. Hand-harvesting is common where fruit or other produce is at various stages of maturity within the crop, that is, where there is need for repeated visits to harvest the crop over a period of time. Machine-harvesting is usually viable only when an entire crop is harvested at one time. An existing collection and reception unit of the cassava harvester was modified and the performance evaluated. The modification made on the machine includes: replacement of the belt conveyor conveying the cassava tubers from the lifting unit to chain conveyor, change in the power source from electric motor to bolting directly to the flanges of the lifting unit of the harvester, introduction of a header to the design to pick the cassava tuber from the soil. The modified design includes a driven sprocket which receives transmission from the reduction gears of the lifting unit at ratio 19:1 to the P.T.O shaft with 2.0 km/h,4.0 km/h and 6.0 km/h speed of the harvester. The parameters varied were forward speed, angle inclination of the conveyor and speed of the conveyor, length of the chain, how the amount of soil that is sifted changes along the length of conveyor. The elevator height is adjusted with the help of adjustable shafts on both sides of the implement, it is based on the bouncing of tubers on the elevator due to variance in size, shape and structure, the height is changed to 35, 40, 45 and 50cm respectively. The elevator height at which there is no damage, no bruising loss, no bouncing of tubers on the elevator is found.
