Design Analysis of a Manual Cassava Harvesting Tool

Abstract

Mechanisation for cassava harvesting is still very low in most cassava growing areas of India due to topographic constraints society of labours. The man-machine system of cassava harvesting is still a major challenge to many small-scale farmers who rely on indigenous tools and implements. Cassava is the most widely cultivated root crop and in southern states of India (Kerala and Tamil Nadu) and is grown across a broad range of agro-climatic conditions. Cassava can be cultivated under both irrigated and rainfed conditions. Under irrigated conditions, this crop can be cultivated throughout the year whereas under rainfed conditions; May-June is the best time before monsoon season starts. Our farmers are not able to buy a tractor or large harvesting machine, hence manual harvesting tools help them for harvesting. Manual cassava harvesting is difficult and full of drudgery especially during the dry seasons when the soil moisture content is low; mechanized alternatives are way beyond the reach of poor farmers. These includes manual devices such as cutlasses and hoes and semi mechanized devices such as prairie mouldboard ploughs. Ridges are used to split the ridge along the crest and pulling by using specially designed blades to cut below the tubers. Generally, animal and tractor drown single disc ploughs are used to harvest cassava. The major components of the harvester include a support stand, lifting arm, lifting medium and the clamp. Best efficiency of manual harvesting tool is achieved when cassava plants are coppiced before harvesting. Some of the design considerations include ease of reproducibility and ability to lift the cassava with minimal damage. The most difficult and cost intensive field operation in cassava performance may be poor, if ergonomics are not given attention. The improper posture during the work and heavy demand on workers biological system, equipment operation cause clinical or anatomical disorders and will affects the health. Design analysis were conducted based on girth diameter of cassava stem in the range of 20.80 to 50.67 mm, at depth ranging from 179.67 to 276.87 mm. The soil resistance was recorded as 1.13 to 4.08 Mpa. The average force required for uprooting was about 150 kgf. Also observed that rod section was superior over pipe section of the handle of the harvesting tool.