By Md. Zakaria Hasan

Background: The Storage Challenge

Bangladesh produces approximately 3.6 million tons of onion annually, while the domestic consumption stands at 2.6 to 2.8 million tons. Despite having sufficient production to meet national demand, the country still imports 0.6-0.8 million tons of onion each year (Bangladesh Bureau of Statistics, 2024). This is primarily due to substantial post-harvest losses, with 30-40% of the harvested onions being damaged before reaching the market due to inadequate storage facilities. Of this loss, around 10-15% is due to moisture loss, while 20-30% is caused by rotting. The introduction of onion storage blowers can significantly reduce rotting losses-from 20-30% down to about 5%-offering a practical solution to enhance onion shelf life and reduce import dependency.

Early Innovation: BWDB's Prototype

Farmers in Bangladesh traditionally store onions in bamboo lofts ("chang"), causing high post-harvest losses-especially during the monsoon when humidity exceeds 80%. In 2020, the Bangladesh Water Development Board (BWDB), under the Southwest Area Integrated Water Resources Planning and Management Project (SAIWRPMP-AF) financed by Asian Development Bank, assessed the onion value chain in Faridpur and identified storage as a key constraint. To address this, BWDB adapted the blower storage system from India for local conditions. In 2021, the prototype was manufactured by Khan Agro, Khulna & RK Metal, Faridpur, and installed at Faridpur Sadar.

By 2022, BWDB demonstrated the initiative with installations at multiple sites, and from November 2022, CIMMYT joined by engaging Agriculture Based Light Engineering (ABLE) workshops to manufacture and market the technology. Since 2019 CIMMYT has been working to boost up private sector led local agricultural machinery manufacturing system through CSISA-MEA in Chattogram, Bogura, Jashore, Kushtia and Faridpur region. Following the conclusion of the BWDB project in June 2023, CIMMYT carried forward the initiative through Cereal Systems Initiative for South Asia-Mechanization Extension Activity (CSISA-MEA)

CIMMYT scientists continue to refine the specifications of the onion blower-such as optimum height, diameter, airflow, and sheet metal thickness-to ensure efficiency and durability. As part of AOW 2: Pathways to Scale in Agrifood Systems, CIMMYT and partners are working to scale affordable onion storage solutions across Bangladesh, enabling farmers to preserve quality and sell onions when market conditions are favorable

In 2023, CIMMYT partnered with two Agriculture-Based Light Engineering (ABLE) workshops through Joint Venture Agreement JVA-Ma Metal (Faridpur Sadar) and Shahin Engineering Workshop (Pangsha, Rajbari)-to manufacture and market onion blower machines. These collaborations included both technical guidance for manufacturing and business development support.

Building on this foundation, in 2024 CIMMYT expanded its engagement to seven manufacturers through JVA, further strengthening the production and marketing of onion blower machines. Support activities included demand-creation meetings with farmers, dealer linkages, distribution of promotional leaflets, and field demonstrations, ensuring both technology uptake and commercial sustainability.

The Bangladesh Water Development Board (BWDB) initially developed an onion blower machine with a 12 & 14-inch diameter and 80-inch height. With CIMMYT's technical support, Agriculture-Based Light Engineering (ABLE) workshops expanded the design to three sizes-12″, 14″, and 16″-while reducing the height to 72-74 inches to make the machines more affordable and cost-effective. To further enhance performance, CIMMYT also helped ABLEs introduce an expanded 19″ taper system, which significantly improved airflow. Building on these refinements, the Department of Agricultural Extension (DAE) is now promoting the improved design-featuring a 16-inch diameter, 72-inch height, and a 19-inch head taper system-through its projects, as formalized in an official circular.

Refining the Technology

Onion storage airflow machine showed strong potential to reduce post-harvest losses and improve storage conditions for Bangladeshi farmers. The system lowered temperature and humidity inside sheds, significantly reducing sprouting, fungal rot, and moisture buildup. This innovative method uses low-cost electric fans installed in a cylindrical metal housing placed at the center of the storage chamber to circulate air evenly through onion stacks. Continuous airflow prevents humidity accumulation, keeps bulbs dry, and maintains a cooler environment, cutting spoilage risks. After curing, onions are stacked with space for air movement, and the blower runs to maintain airflow-extending shelf life by several months. This allows farmers to store onions longer and sell when market prices are more favorable.

Enterprise Growth: Shahin Engineering Workshop

In 2023, guided by CIMMYT's technical support, Shahin Engineering Workshop in Pangsha, Rajbari began producing onion storage blowers, priced between BDT 15,000-20,000, to help reduce year-round onion spoilage. Production quickly scaled up-from about 40 units in 2023 to 250 in 2024 and reached 1,500 units by 2025.

To ensure product quality, CIMMYT trained the workshop owner to use tachometers for measuring RPM, anemometers for airflow, and wire gauges for sheet thickness. By 2025, the company had grown into a sizable enterprise with 34 employees, including 26 skilled technicians, 8 marketing officers, and a computer operator, achieving an annual turnover of more than BDT 30 million.

Through CIMMYT's facilitation, Shahin Engineering Workshop also established formal linkages with the Department of Agricultural Extension and became a key supplier to the Ministry of Agriculture's Rehabilitation Program-solidifying its role in reducing national post-harvest onion losses.

Technology Adoption and Promotion

"The Department of Agricultural Extension (DAE) now actively promotes this technology and recognizes CIMMYT's contribution. Mr. Tofajjal Hossain, Upazila Agriculture Officer, DAE, Pangsha, Rajbari, stated: 'The onion storage blower is a game changer for preservation, significantly reducing post-harvest losses, maintaining quality for months, and providing farmers with a cost-effective, reliable storage solution."

Future Directions: Smarter and Sustainable Blowers

A small onion blower can store 8-10 tons of onions and costs only about USD 165, making it an affordable solution for farmers. CIMMYT is currently working to further enhance this technology by integrating an automatic time-based controller, a thermocouple-based sensor, and a solar-powered operating system. These upgrades are designed to improve energy efficiency, automate operation, and ensure the blower is both sustainable and farmer-friendly.

To accelerate adoption, the Additional Director's Office in Faridpur, with technical support from CIMMYT, published 10,000 informational leaflets on onion blower technology. At the policy level, the Ministry of Agriculture has recently announced the distribution of 4,000 blowers to small and marginal farmers under the Agricultural Rehabilitation Program. In parallel, the Department of Agricultural Extension (DAE), through the Bangladesh Climate Change Trust Fund (BCCTF), will distribute an additional 3,700 blowers across major onion-growing districts.