Grading Chinese potatoes (koorka) based on their size has for long been a major headache to farmers, given the time and labour charge involved in it. Now, the Central Tuber Crops Research Institute (ICAR-CTCRI) in Thiruvananthapuram has been granted a patent for a power-operated, size-based Chinese potato grader and a method of grading.
The grader, which cuts down labour and cost significantly, works on the principle of rotating motion of the unit through a prime mover. It sorts the tubers into four different size classes; small (below 20 mm diameter), medium (20.1-30 mm), large (30.1-40 mm) and very large (above 40 mm), according to the CTCRI, an institute under the Indian Council of Agricultural Research (ICAR).
The patent has been granted by the Indian Patent Office.
“Farmers resort to manual grading which requires 50 man days of labour for sorting tubers harvested from one hectare. This machine needs only two man days for sorting the same quantity,” T. Krishnakumar, the CTCRI scientist who is the lead inventor of the technology, said. Other scientists involved in its development are M.S. Sajeev, Principal Scientist, C. Pradeepika, Scientist, R. Muthuraj, Principal Scientist, and D. Jaganathan, Senior Scientist.
CTCRI took up this project based on a needs-assessment survey of Chinese potato growers considering the very high expenditure on manual grading which significantly reduces the profit of the growers who are mostly resource-poor people concentrated in the districts of Tenkasi and Tirunelveli in Tamil Nadu and Thrissur, Palakkad and Ernakulam in Kerala.
The machine can grade/sort one tonne of tuber in an hour for which the average cost including labour is ₹150 whereas manual grading of the same quantity costs ₹1,500. The grader consumes 0.75 kW per hour electricity, with an average power cost of ₹5 per hour, the CTCRI said.
CTCRI has commercialised the technology by issuing a non-exclusive license to M/s Stoneheat Technologies, Rajapalayam, Tamil Nadu.
