Technical fixes needed to stem crop losses

A precious harvest: grain processing in Mali Copyright: Flickr/World Bank Curt Carnemark

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[LONDON] More than half of crops planted in developing countries are destroyed by pests and diseases, and by inadequate storage or transport, a global food summit has heard.

Thirty to forty per cent of crops are lost before harvest and more than ten per cent after harvest, according to Food Security in a Climate of Change, a conference run by CABI, a not-for-profit agricultural organisation.

"This is not just wasted food, this is wasted labour, fertiliser, energy and water," Julie Flood, global commodities director at CABI, told the London meeting this week (20 October).

There has been much focus on increasing yields, said Dennis Rangi, CABI’s executive director for international development. "But increased production is of little value if farmers lose a large proportion of their crops to pests and disease. As farmers are supported to grow more they must also be supported to lose less of what they grow."

"Rising travel and trade increases the risk that imports will contain unwelcome stowaways that have the potential to devastate our natural resource base."

Rangi highlighted the larger grain borer, an insect that is "eating its way through the grain stores of Africa" after it was imported in grain donations in the early 1980s. The pest costs Tanzania almost US$90 million annually in lost maize.

He told SciDev.Net that scientists need to develop quick-fix technologies. "The problem is that farmers get very desperate, and when they get desperate they end up using lots of pesticides that also begin to cause other problems."

"We need to come up with technologies and science — such as improved crops or biological control — that can really help manage pests," says Rangi. He adds that most of CABI’s work concentrates on pests and diseases but that there are many avenues to pursue.

"There are several quick wins that could be made. They include improved knowledge sharing, quarantine, storage and diagnosis of crop pests and diseases, and increased surveillance and early warning systems for monitoring their spread."

Akinwumi Adesina, vice president of policy and partnerships at the Alliance for a Green Revolution in Africa, told the meeting that African governments should be getting involved in combating post-harvest losses.

He suggested the creation of crop processing zones for staple foods. These would be well-supported with infrastructure such as energy, roads and water and would allow Africans to convert their staple crops into new sources of income.

Flood said that it is not just pests and diseases that lead to crop loss. "In any discussion about losing less we have to address the issue of improving plant health in general. Awareness is not high and we have to improve the knowledge of producers."

She told delegates about CABI’s Global Plant Clinic , an initiative where local ‘plant doctors’ — usually agricultural extension workers — hold workshops for farmers (see A new vision of plant health services for world’s poor).