Low-cost cold storage benefits small-scale horticulture farmers in Makueni County

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Small-scale fruit farmers in Kenya’s rural areas were introduced to a locally adapted cooling technology that will see them reap huge benefits from selling their produce in a more organised manner. The farmers are excited about the prospects of using the “Coolbot” technology and can hardly wait for another crop season.  “If I use the technology again during the next season, I will buy a pickup (van) from selling my mangoes”, says an excited Wilfred Mailu,   a farmer from Makueni County in an interview with NTV, a popular national television station. The farmers had just completed the first trial phase of the technology with researchers from the University of Nairobi.

Farmers in Kenya’s rural areas record in excess of 50 percent postharvest losses for fruits and vegetables.  These looses can be attributed to poor postharvest handling practices and lack of means to access appropriate technology leading to huge losses in the food value chain. Due to lack of appropriate storage technologies for the perishables produce, most of the  farmers are forced to  sell their produce at low prices for fear of spoilage.

Cold storage is an important component in the horticultural value chain, which deals in perishable commodities. However, the majority of smallholder farmers cannot afford the cost of conventional cold rooms, and solutions that offer viable alternatives within the means of small-scale farmers can go a long way in enhancing farmers’ earnings. Research indicates that the technologies have the potential to cut down on the huge postharvest losses incurred by farmers. Use of the technologies will also buy time for the farmers as they look for better market options to negotiate for higher prices. In a recent market survey, Dr. Jane Ambuko, a postharvest researcher showed that during the peak season, the farm gate price for mangoes in Makueni is as low as Ksh 3 per piece. However, in Nairobi (Kenya’s capital city), the same fruits are sold for as high as Ksh 66. 

Coolbot technology













The “Coolbot” is an invention by a small-scale farmer from the USA. This electronic device makes it possible to achieve much lower temperatures than is the case with the conventional air conditioner. Ordinarily, a standard air conditioner lowers temperatures to 18⁰C but temperatures as low as 0⁰C can be achieved using a Coolbot.  This means that the Coolbot modifies the functioning of a standard air conditioner making it possible to convert an insulated air conditioner-fitted room into a cold-room.  The user can select the desired temperature to be maintained in the cold room . 


In a research project to test the efficacy of the Coolbot device, researchers achieved the set temperature of 10⁰C and effectively converted the adapted storage room into a walk-in cold room.  They were also able to store mangoes in the cold storage for 35 days without modified atmosphere packaging (MAP) and 45 days with MAP. Mangoes stored under ordinary room temperature conditions began to spoil after only 12 days. 


In a cold storage room constructed in Makueni County, farmers were able to store their harvested fruits for two weeks. At the end of the two weeks, the farmers sold their mangoes at a profit sale of Ksh 23 per mango.  Further, University of Nairobi researchers trained the farmers on the basics of fruit harvesting, including sorting, grading, and packing which are critical in postharvest quality preservation .


Challenges experienced during the trial phase  was failure by the farmers to  pre-cool the mangoes by washing before taking the fruits to the cold room or harvesting the mangoes either early in the morning or late in the evening. Subsequently, by filling the cold room with hot mangoes, the trial did not achieve the optimal storage period to allow farmers more time to find market outlets for their mangoes at a higher price.  This has led Dr. Ambuko and her colleagues to seek alternatives for pre-cooling the mangoes, which the farmers can adopt without difficulty. 

Potential benefits

According to Dr. Ambuko, the cold storage room at Makueni, with the capacity to hold 1 ton of mangoes, was constructed at Ksh 400,000, which is less than half the cost of a conventional cold room of similar size. The trial period involved 15 out of 100 farmers from Kawala Smallholder Farmers Horticultural Group but the other farmers have expressed their interest in participating in the project during the next season. According to the researcher, the optimal use of the cold storage facility has the following potential benefits for farmers and consumers:

  • Extended shelf life and hence marketing period for perishable farm produce
  • Farmers can bulk their produce and enjoy better bargaining power in the market
  • Farmers will have the opportunity to venture in production of other high value perishable crops
  • Consumers will have a steady supply of fruits and vegetables at stable prices


The research involved other researchers from the University of California, Kenya Agricultural and Livestock Research Organisation (KALRO), and Jomo Kenyatta University of Agriculture and Technology (JKUAT)The project was sponsored by the USAID under the Kenya Feed the Future Engine (KFIE).

Dr. Jane Ambuko      

Department of Plant Science and Crop Protection, University of Nairobi