Turmeric is a very popular spice in Bangladesh, and it is also widely used in rituals and as a medicine. Turmeric is grown across about a tenth of the country's area, and it makes up a large part of jhum cultivation across the wide hill areas.

There is great scope for growing turmeric on shaded flat land. The crop is grown on about 18,000 hectares nationwide, with total output of about 72,000 tonnes. Production can be raised further by expanding the area under turmeric varieties developed by BARI.

After harvest, turmeric is processed in stages: cleaning, sorting, boiling, drying, polishing and grinding. Boiling and drying 40 kg of raw turmeric gives 8 to 10 kg of dry turmeric. To get good-quality turmeric of the desired colour, it must then be polished before grinding. If polishing is not done properly, the skin mixes with the powder and spoils its quality and colour, and can even harm health. Farmers usually polish turmeric by beating it by hand in sacks. In hill areas, sacks of turmeric are tied in front of bamboo dhenki pounders to polish them. A modern machine would therefore be better.

• It can be made from locally available iron materials.
• It can be run by an electric motor of just 0.5 horsepower.
• One person can operate it easily.
• Polishing turmeric while still hot after sun-drying raises capacity and improves quality.

• It is made of MS angle bar, MS rod, MS sheet, MS flat bar, D-pulley, reducer gearbox and bearings.
• Grooved plates are fitted inside a hexagonal drum.
• The rotating hexagonal drum is 610 mm long, with an outer diameter of 690 mm and inner diameter of 590 mm.
• Machine size: 1,040 x 850 x 1,450 mm.
• Turmeric per batch: 30 kg.
• Weight of machine: 90 kg.
• Capacity: 65-90 kg an hour.
• Labour needed: one person.
• Price: Tk 30,000 (including motor).

Set the machine up on a flat, open place without shade. Before polishing, boil the turmeric as needed and dry it well. On the day the machine is used, drying it again in the morning sun and warming it slightly raises threshing capacity and quality. First, pour 30 kg of turmeric into the hexagonal drum with a basket and close the door tightly. Connect the motor to the power line with a cable. When switched on, the motor starts and the drum rotates. As it turns, the grooved inner surface cleans the outer skin and dirt from the turmeric, and the dirt falls out through gaps in the drum. One batch is polished in about 20 minutes. Open the drum door to take out the polished turmeric, then load a new 30 kg batch. After every use, clean the machine thoroughly, lubricate the rotating parts as needed and store it in a safe place.

Source: Jagonews24. First published in Bengali on The Agro News.