Cassava, a ubiquitous crop in Uganda
As you crisscross the Ugandan countryside, the distinctive leaves of the cassava plant catch your eye everywhere you look. Cassava roots can be seen piled high along the roadside ready for sale. Sold in heaps of three to five, the freshly harvested roots are usually found still covered in soil fresh from harvesting.
The Ugandan cassava customer is a discerning one with a great ability to select the best roots for consumption chosen by assessing color, texture, skin type, size and shape. For urban consumers in cities like Kampala and Entebbe the right variety of cassava, purchased within a few hours of harvest and grown in favorable conditions, is a delicacy and a must-have ingredient in many meals. For those in the countryside, with less disposable income, cassava is the food security crop of choice. It gives children the energy to concentrate in school, parents the strength to work and also provides many farming families with a much needed income to pay school fees, buy food and look after the daily demands of life.
Alleviating pressure on cassava farmers and traders
Throughout Uganda, there is severe pressure on cassava farmers and traders to sell the crop immediately after harvesting. To cope with this, they are often forced to sell at a lower price if they still have roots to sell a day or two after harvest. This drop in price alongside large amounts of wasted crop that spoils before it is sold places undue pressure on smallholder farmers and traders who are already very economically vulnerable actors in the value chain. Creating a longer lasting root would give these actors more freedom to market and transport their crop and to have a more powerful voice in the transaction process with customers.
Extending the shelf-life of fresh cassava roots
We make our way to a research facility on the outskirts of Kampala, managed by the National Agricultural Research Organization (NARO) of Uganda. Here, a group of scientists are researching how to extend the shelf-life of fresh cassava roots. By doing so they hope to transform the cassava industry which could increase incomes for individuals along the value chain and reduce post-harvest losses and food waste.
Sharon Acheng, a second year masters student at Makarere University is a young researcher who believes strongly that agricultural research for development can improve lives. Sharon is one of three students conducting post-graduate research on cassava in coordination with NARO and the CGIAR Research Program on Roots, Tubers and Bananas.
Sharon is contributing to research on how applying a wax coating over the root could improve cassava shelf life. Widely practiced in Latin America and the Caribbean, waxing has proven to extend the shelf-life of fresh cassava roots to over 30 days which creates the possibility for new market opportunities. This kind of technology would be a game changer in Uganda where rapid deterioration of the crop has severely limited growth of the domestic and international market.
To conduct the research, Sharon receives cassava from the field to trial with the wax technology. After scrubbing and drying, the roots are dipped in a disinfectant and fungicide solution. Sharon brings over a large tub of wax to show us: "We heat the wax to 160-200 degrees centigrade and then dip the cassava into the wax, making sure it is completely covered for a few seconds. Then you leave it to dry in just a few seconds. Fresh cassava roots are highly perishable and spoil within three days of harvesting which means that cassava must be eaten very quickly. Wax, creates a curtain over the cassava which covers the entire root and slows the perishing process."
"We are still in the process of testing the technology. We are using different samples to compare post-harvest physiological deterioration (PPD) to see what effect wax has and for how long. We want to understand the role that wax can play in preserving cassava so that we can then make recommendations to those in the cassava value chain," explains Sharon.
South-south collaboration and capacity development
The team working on cassava technologies travelled to Cali, Colombia in 2015 to learn about a range of post harvest practices and technology from International Center for Tropical Agriculture (CIAT) and CIRAD scientists. The team also received invaluable support from Elias Rico, a private sector entrepreneur in Colombia, who shared his experiences using these technologies.
The Ugandan team learned key lessons during this collaboration. Firstly, that for waxing and relative humidity technologies to be effective agronomic and pre-harvesting practices must be improved. Pruning affects the efficacy of these technologies in extending the shelf-life and can change product taste so must be integrated into harvest practices.
Secondly, the team learned that technologies which extend shelf-life work best for undamaged roots. As such, ridge planting, which minimises damage to roots during harvesting, should be advised. And thirdly, the team learnt the critical lesson that entrepreneurial drive is a critical component of business development and Elias Rico shared some inside tips on challenges and opportunities he had found with his business in Latin America.
The team learnt about a variety of technologies including waxing, pruning prior to harvest (six days before harvesting) and PPD. The team learnt that these techniques are synergistic and together can provide extended shelf life of up to one month. In Latin America these technologies have been used by industry with great success. The expertise shared with the visitors is being shared amongst the large team of scientists working on the cassava industry in Uganda.
Developing young scientists to work on relevant, demand driven research
We are joined by Harriet Muyinza, the project investigator at NARO. Harriet emphasizes the importance of the CGIAR and NARO collaboration which allows the RTB ENDURE project to harness existing knowledge and expertise from the national agricultural system. The collaboration also helps to develop the capacity of young researchers who will lead the way in dealing with food and nutrition security issues in the years to come.
Harriet emphasizes how important it is for NARO to participate in agricultural and scientific research which is relevant to the national agricultural agenda and which will provide direct impact for the people of Uganda: "Uganda is the sixth largest producer of cassava in Africa so this research is extremely important for the country. We think this technology is very relevant for smallholder farmers, especially those who depend on the fresh food market."
"Over the coming months, we will test this technology in a variety of ways to understand its optimal use across a number of cassava varieties. Once we optimize the technology, then we shall look at ways to take the technology to market in an affordable and accessible way. We are also increasing our understanding of the inherent differences across the available varieties and their natural ability to delay deterioration,". says Harriet