Post-harvest technologies pay off for cowpeas

Cowpea is an important source of nutrients in semi-arid parts of Africa

Flickr/IITA Image Library

Tricks that prevent the rotting of cowpeas, an African staple, after they have been harvested, will have yielded US$295 million of benefits in west and central Africa by 2020, according to new research.

Solar powered heaters to kill pests, simple, airtight containers and other storage technologies developed between 1982 and 2007 through the Bean/Cowpea Collaborative Research Support Program (CRSP), are having a dramatic impact on production of the bean (Vigna unguiculata), an important source of protein in semi-arid regions of Sub-Saharan Africa, the study has shown.

The programme — now known as Pulse CRSP — works with the US Agency for International Development (USAID) to support research and extension links among West and Central African cowpea researchers and their US counterparts.

The collaboration has led to improved storage technologies that are now used for nearly a third of grain in the region, the study says.

The researchers measured the economic impact of the non-chemical technologies in seven countries — Benin, Burkina Faso, Cameroon, Mali, Niger, Nigeria and Senegal — which account for more than 96 per cent of the region's production.

They surveyed about 800 randomly selected village cowpea farmers and added price data from several sources. The results, were published in the July issue of Journal of Stored Products Research.

"If the cowpeas are stored in airtight containers, such as a triple bag or metal drums, the [pest] insects quickly use up the oxygen, the oxygen level drops, and the insects either die or leave the cowpeas so they don't cause any more damage," said James Lowenberg-DeBoer, a co-author of the research and a professor of agricultural economics at Purdue University, in the United States.

He added that the technologies mean that millions of poor farmers can improve their income from selling produce especially during the seasons when cowpeas is scarce. The improved technologies also reduce the application of pesticides during cowpea storage, which can lead to poisoning.

Several reports have recently outlined the importance of using existing and new technologies to cut post-harvest food loss and waste, which is as high as 30 per cent of all produced food globally.

Ousmane Coulibaly, an agricultural economist with the International Institute of Tropical Agriculture (IITA) in Benin said the study probably underestimated the total economic benefits.

"Cowpea provides protein and thus prevents nutritional diseases particularly in poor people, which can also lead to economic gains."

And Adeola Olufemi Oyebanji, the officer-in-charge of the Nigerian Stored Products Research Institute said that the study considered improved technologies only at the rural level and therefore did not reflect the overall regional economic benefit.

"There are huge economic gains for large industries that use improved technologies for cowpea storage too," Oyebanji said.