Comparative evaluation of manual cassava harvesting techniques in Kerala, India
Keywords:cassava, field capacity, drudgery, coppiced, efficiency
Abstract: In India, cassava is consumed as a secondary staple along with the main staple, rice, and many rural poor consume it as the staple in different forms of preparations. Though harvesting is known to be one of the most difficult and cost-intensive field operation in cassava cultivation, mechanisation of cassava harvesting is still very low in most cassava growing areas of India due to topographic constraints, methods and scale of cultivation. The most viable solution to overcome these constraints is to promote the use of more efficient manual harvesting tools. Thus, the main objective of this study was to field evaluate the efficiency of four manual cassava harvesting techniques under different land preparation methods in terms of field capacity, level of drudgery and root tuber damage or breakage. The study also sought to investigate the effect of cassava agronomic parameters on uprooting force requirement. Field study was carried out at the Central Tuber Crops Research Institute (CTCRI) research field (under upland mound method) and at Chenkal village on farmers’ fields (under lowland flat method); both in the Kerala state of India. Harvesting was done using the CTCRI lever, prototype harvester, hoe and manual uprooting (control) techniques. Results from the study showed that the use of manual harvesting tools is preferable on relatively dryer soils, whereas manual uprooting technique is best suited for soils with relatively higher moisture contents. However, best efficiency of manual harvesting is achieved when cassava plants are coppiced before harvesting. Also, cassava uprooting force requirement, to a greater extent is influenced by root tuber yield, root depth and number of root tubers per plant, especially under upland mound land preparation method. It is however recommended that a user performance assessment and economic feasibility analysis of the prototype harvester and CTCRI lever be conducted with farmers to facilitate future design modifications, where necessary and to support future adoption. As a design recommendation, the pressure at the fulcrum for both the CTCRI lever and prototype harvester should be reduced to avoid sinking during harvesting in soils with relatively higher moisture contents.
Keywords: cassava, field capacity, drudgery, coppiced, efficiency