Safe and Low cost Ripening Technology of Fruits, an IIHR Technology

IIHR is the Premier Centre in India under ICAR that serves as a repository of scientific information pertaining to Horticulture. They also act as a center for training and up-gradation of scientific manpower in modern technologies for horticulture production. They actively undertake basic and applied research developing strategies to enhance productivity and utilization of to undertake basic and applied research for developing strategies to enhance productivity and production of horticulture crops.

Many Farmer Centric technologies as many as 150 of them have been developed for the farmers here at the Institute and they have been conducting regular workshops to impart training to the farmers on all these aspects. At Present in the COVID-19 Crisis, they also have been very active in establishing value chains for the farmers whom they were associated with.

A Safe and Low Cost Ripening Technology of Fruits is been developed by IIHR and this is a simple method for enhancing the ripening process by exposing the fruits to ethylene gas released from liquid ethrel/ethephon. It does not require any sophisticated equipment. It can be used by commercial growers, traders and retailers as an alternative to banned calcium carbide method says Dr. D.V. Sudhakar Rao, Principal Scientist, Division of Post Harvest Technology, Indian Institute of Horticultural Research (IIHR), Bangalore.

Natural ripening of fruits harvested at mature green stage is slow leading to high weight loss, desiccation and in some cases uneven ripening. Traders still widely use banned chemical agents like calcium carbide for enhancing the ripening of fruits. Ethylene gas is commercially used in modern ripening chambers which requires huge investment and may not be economical for small farmers or small traders. This is a simple method wherein small quantity of alkali is added to liquid ethrel to release the ethylene gas and the fruits are exposed to this liberated gas in air-tight portable plastic tents or airtight rooms.

The Method

• lace the mature fruits in ventilated plastic crates and put them inside an air-tight plastic tent/chamber/room

• Take the Required (2 ml per every 1 cum room size) quantity of ethrel into a container and place it inside the tent/room

• Add the required quantity (@ 0.25 g per every 1 ml ethrel used) of sodium hydroxide (caustic soda) for releasing the ethylene gas from liquid ethrel and seal the tent airtight immediately

• If required, a small battery-operated fan can be placed inside the tent/room for uniform circulation of released ethylene gas

• Open the tent after 18-24 hours of exposure and shift the crates to ambient temperature or low temperature of 20-24°C (only in the case of Robusta and Grand naine bananas) for completing the ripening process.

Note: The tent/room should be filled with fruit crates up to approximately 70% of the room size. The above quantity of ethrel is for 39% purity which is commercially available in the market. Reduce the quantity accordingly when using high pure ethrel.

Important: The tent or room should be sealed immediately as soon as possible after adding caustic soda. Otherwise, the liberated ethylene gas will escape from the room

Mango fruits thus exposed will be ripened in 5 days at ambient temperature as compared to 10 days in non-treated fruits. Similarly, banana bunches/hands can be ripened in 4 days at ambient temperature and 6 days at 20°C. For the ripening of papaya and sapota, the quantity of ethrel can be reduced to half of that recommended for mango and banana.

Tent Size and capacity:

1 cubic meter (1 m x 1 m x 1m) tent can accommodate 200-250 kg mangoes

4 cubic meter (1.6 m x 1.4 m x 1.8 height) tent can accommodate 1 tonne of mangoes

1 cubic meter size ripening tent

1-tonne capacity 4 cubic meter size ripening tent

For further information please contact: Director, IIHR (080-28466420 to 23) or Dr. D.V. Sudhakar Rao (9900820270), Principal Scientist, Division of Post Harvest Technology (080-28466420 ext 373), Indian Institute of Horticultural Research (IIHR), Bangalore-560089

Content Courtesy: IIHR