Technology is helping to greatly reduce post-harvest bean losses

Around the world, 690 million people regularly go to bed hungry, and the figure is likely to exceed 840 million by 2030, according to a report by the United Nations food agencies.

Sub-Saharan Africa has the highest prevalence of undernourishment, estimated at 22 per cent of the population. This is expected to increase to 29.4 per cent by 2030. The number of hungry people continues to grow with the Covid-19 pandemic coupled with the devastating impacts of climate change. Ironically, food losses in sub-Saharan Africa amount to about Sh429 million ($3.9 million) annually.

Increasing the area under production is seen as an immediate strategy to addressing food shortage. Unfortunately, land is finite and such increase in conversion of natural land to agriculture comes with serious environmental and global changes in form of land degradation (soil erosion, deforestation, pollution, greenhouse gas emission) and climate change.

A reduction in food losses could have an immediate and significant impact on the livelihoods of millions of smallholder farmers in developing countries living on the margins of food insecurity. It could also reduce the growing food deficit and save households valuable income.

Sustainable Development Goal (SDG) 12 of Agenda 2030, seeks to “ensure sustainable consumption and production patterns”. Target 12.3 of that goal aims to halve the per capita global food waste at the retail and consumer level, and reduce food losses along production and supply chains including post-harvest losses.

Food loss typically takes place at the production, storage, processing, and distribution stages of the food value chain, while food waste refers to food, which is of good quality and fit for consumption, but is not consumed because it is discarded either before or after it is left to spoil. Most food loss across Africa happens between harvest and the point of sale, while very little is wasted by consumers after purchase.

Pest and disease management

Pan Africa Bean Research Alliance (Pabra) together with national partners are investing in technologies and promoting knowledge on their use to reduce food losses as part of the strategy towards achieving food security, food safety, improving food quality and delivering on nutritional outcomes.

Food loss starts from the farm, so is food loss management. At farm level, Pabra is promoting use of good agricultural practices for pest and disease management to guarantee quality harvest. Use of Integrated Pest and Disease Management (IPDM) is aimed at judicious use of agrochemicals to reduce food contamination. Proper crop nutrition is geared towards ensuring high quality and nutritious produce gets to the market. This is achieved through training and learning alliance with the bean producer groups.

Majority of bean farmers thresh their crops manually. Use of sticks results in high proportion of grain breakage, which reduces quality and storability. Also, the beans scatter during threshing, resulting in strenuous process of collection. Manual winnowing after threshing is also tedious and time consuming. Using motorised threshers with capability of threshing and winnowing can reduce grain losses and improve the quality for markets. Pabra is partnering with the private sector to develop and promote motorised threshing equipment.

In Tanzania, for example, Pabra partners with ImaraTech Ltd, to develop and multicrop thresher for beans. The machine is capable of threshing eight bags of beans in a day with a breakage of zero to six per cent per bag. The machine has been enhanced with a winnower to improve the grain cleaning process. Using such equipment is helping to minimise physical grain loss during manual threshing and improves the final grain quality. The threshers have been promoted widely in Tanzania and are being scaled out in countries across the Eastern and Southern Africa region. The machines are making the threshing process safer, faster and less labour intensive.

Proper drying of bean grain is important to improve quality and storability. With proper drying, the risk of moulding and aflatoxin contamination are reduced. Most smallholder farmers dry their grain in direct sunlight. At harvest time, all too often rain can damage the grain being dried. Cloudy days means there is no sunshine to dry the grain. This means the drying will take nearly two weeks. This increases the risk of molding and aflatoxin contamination.

Working with private sector partners, Pabra is promoting drying innovations such as use of solar bubble driers. The drier uses solar energy to generate a stream of hot air into an inflatable transparent tube. The hot air is blown over grain causing the grain to dry. The drier can perform even with the little light of day enabling drying grain during the cloudy days. Further, the grain is enclosed in a transparent plastic bubble meaning that it is protected from rain or any other contamination during the drying period.

The technology has been successfully tested and is being promoted in Burundi, Kenya, Tanzania and Uganda.

Tarpaulins and hermetic technologies 

In addition farmers can dry their beans on tarpaulins. Drying beans on bare ground results in contamination of grain with soil as well as physical loss due to scattering. The drying tarpaulin is a waterproof post-harvest solution important for drying a range of agricultural commodities including cereals and pulses. Spreading grain on the tarpaulins prevents contamination of the grains and ensures uniform drying.

Finally, hermetic technologies enable storage of grain in airtight containers without the need to use chemical preservatives. Under the airtight conditions, insects cannot multiply to destroy the grain. Some of the technologies include hermitic storage bags, metallic silos and cocoons.

These and many other technologies can go a long way to safeguard the harvest. Opportunities exist for greater partnerships to address food loss and thus improve food security and nutrition of millions of smallholder farmers in Africa.