1Agricultural Energy and Power Division, Central Institute of Agricultural Engineering, G.T.B. Complex, T.T. Nagar, Bhopal-462 003, (M.P.).
2Central potato Research Station, Jalandhar-144 003 61.
Prototypes of hand and power-operated oscillating sieves potato size-graders and flat belt feed conveyor attachment were developed and used satisfactorily at the Central Potato Research Institute, Shimla for the past few years for sorting seed potato tubers. The construction, method of operation, field performance and economics of these size-graders have been given in this paper. On an average these size-graders sorted out 20 to 28 q/h of seed potatoes into 3 to 5 size grades employing 9–12 attendants. The sizing efficiency ranged from 80 to 90 per cent and average tuber damage was within 2%. The cost of operation of power grader was found lower particularly for higher annual use.
