Ergonomic Comparision Of Two Groundnut Harvesting And Shelling Methods
Ugwu K.C, Oluka S.I
Key words: Harvesting, Groundnut, Ergonomics, shelling, heart rate, Anthropometry
ABSTRACT: An ergonomic study on groundnut production was carried out with five farmers used as subjects. Two harvesting techniques were investigated. Harvesting method I involved involved plucking of the pods from the plant on the field while harvesting method II involved uprooting the whole plant (including pods) after which the pods were plucked from the plants in a sitting posture. Mechanical shelling was performed and compared with manual shelling. The parameters measured on the subjects included heart rate, body temperature, blood pressure, and anthropometric measurements at each working postures. The area of groundnut plots harvested together with the weight of groundnut shelled as well as the time spent in each case were all measured. The field capacities, energy expenditure rate, shelling capacity, spinal extensor muscle force as well as the total reaction on the lumbosacral joint were determined for both harvesting methods. Results obtained indicates that, for harvesting methods I and II, energy expenditure rates for harvesting are 5.3kJ/min and 3.7kJ/min, energy expenditure rates for shelling are 4.5kJ/min and 5.3kJ/min, field capacities are 36m2/h and 44m2/h, shelling capacities are 65kg/h and 12kg/h, spinal extensor muscle forces for harvesting are 2.9kN and 2.6kN while that of shelling are 0.5kN and 1.5kN, total reaction on lumbosacral joint during harvesting are 3.1kN and 2.7kN while that of shelling are 0.9kN and 2.0kN. Generally, harvesting method I produced higher values in field capacity, increase in energy expenditure rates, spinal extensor muscle forces and total reaction on lumbosacral joint than harvesting method II, while mechanical shelling produced higher values in shelling capacity and increase in energy expenditure rate, but lower values in spinal extensor muscle force and total reaction than manual shelling. These lower values obtained for the parameters associated with harvesting method II and mechanical shelling mean lower physiological stress which is good for the subject. It is therefore recommended that harvesting method II (uprooting the groundnut plants first and later pluck the nut in a sitting position) and shelling mechanically is a suitable combination of operations that can be adopted in groundnut production whenever a mechanical harvester is not available.
 Davidson S. (1968); The principles and practice of medicine including supplement on tropical disease. The English language book society, pp. 138 154.
 Ettema J. H. (1967); Arbeidsfysiologische aspecten van mentale belasting. Assen Cited from Zander; (1972) pp. 65.
 Hammos, R.O (1994); The Origin and History of Groundnut in Smart, J Edition The Groundnut Crop: a Scientific Basis for Improvement , Chapman and Hall, New YorkUSA.
 Leveau,B (1977); Biomechanics of Human Motion 2nd Edition, W.S Sauders Company, Philadelphia.
 Nwuba, E.I U and Kual R.N. (1986); The Effect of Working Posture in the Nigerian Hoe Farmer, J.A.E.R vol. 33 pp 179-185.
 Shankarappa, T., Robert, E.R and Virginia, N (2003); World Geography of Groundnut,Distribution, Production use and Trade, Available at http://www./anra.anthro.uga.edu/peanut/ nowledgedatabase(accessed April 20, 2010).