Scientists bring hope of better crops

Frequent warnings about approaching agricultural epidemics must be balanced with the solid advances made in producing hardier and higher-yielding varieties of Africa’s staple crops. We round up the latest discoveries.

Headlines promising disaster are commonplace in the agricultural press about Africa. ‘Africa threatened by evolving, deadly wheat pathogen.’ ‘Banana blight puts livelihoods at risk.’ ‘Virus ravages cassava plants in Africa.’ There is plenty of work for the men in white coats as new threats promise to wipe out cassava or banana crops in the next epidemic to mirror the potato famine. However, this year, scientists have made substantial progress on protecting and improving Africa’s main staples: bananas, cassava, maize and rice.

The discovery of new and more robust crop varieties are becoming an ever more regular occurrence. In 2010, there seems to be more good news than bad. In late August, UK scientists announced that they had decoded the wheat genome, which is more complex than the human one. This will allow researchers to develop higher-yielding and disease resistant variants.

Also in late August, the Drought Tolerant Maize for Africa Initiative, operated by the International Institute for Tropical Agriculture (IITA) and Centro Internacional de Mejoramiento de Maíz y Trigo, announced that the dissemination of 50 new varieties of maize could lead to a production revolution. If the new drought-resistant strains were delivered to 13 leading African maize producers, the researchers estimate that it would boost production by about one third and provide additional food and income worth more than $500m. Access to new seeds and technology are the main barriers to a revolution of this sort. That means more funds are needed and attention devoted to training, information-sharing and access to credit for smallholder farmers.

Better bananas

Scientists have also made advances in protecting Africa’s banana harvests. Banana xanthomonas wilt (BXW) was first identified in Ethiopia in the 1970s and since 2001 has spread to all of the countries between Kenya and the Democratic Republic of Congo, causing hundreds of millions of dollars in lost revenue. The IITA announced an important breakthrough in August when its scientists were able to transfer green pepper genes into banana plants, leading to resistance to BXW-causing bacteria. Field tests are now being rolled out in Uganda in collaboration with National Agricultural Research Organisation and the African Agricultural Technology Foundation.

Crafting cassava varieties

The fight against brown streak disease in East African cassava is worrying researchers anew after recent advances in fighting the most dominant plague to cassava plants, mosaic disease. International agriculture experts estimate that the two diseases routinely ruin $1bn in African cassava crops each year.

But the threats to African agriculture help to create working partnerships across the globe. Cassava is the third most important source of calories across the globe, following rice and wheat, and scientists and donors are focusing more time and attention on its protection and improvement.

Poorer farmers are also the least able to protect their crops. Research is needed for both hardier varieties and higher-yielding seeds. A major constraint holding back agricultural development in Africa is low yields. Agriculture in Asia and Latin America was revolutionised between 1960 and 2000 when new varieties were introduced and food production tripled. Average maize yields per hectare in Angola and Mozambique are less than 1tn/ha, whereas irrigated maize production in Egypt yields an average of more than 6tn/ha.

Long-term planning

Agricultural research is a long-term process which requires steady financing in order to help stop today’s threats from becoming tomorrow’s famine. Traditional breeding methods typically take about ten years to develop.

Brown streak disease in cassava has been on the research radar since the mid-1990s, when the UK’s Natural Resources Institute identified it as the most devastating cassava disease in coastal regions of Tanzania and Mozambique. While worries increased this year as the disease spread from low-lying coastal areas to other parts of Tanzania and Uganda, IITA scientists pointed out that several high-yielding and tolerant crops had been piloted and rolled out by international partners in Zanzibar since 2007. What remains it a problem of funding and capacity: even with Zanzibar’s small population, supply for tolerant crops cannot keep up with demand. Institutions across the globe are working on the fight against diseases like brown steak, but despite its importance to international food security, cassava research is poorly financed.

Concerns about food security and adverse weather are driving innovation, but players in Africa’s budding biofuels industry also watch developments related to cassava, especially in Nigeria. Ekiti State, Nigeria is taking the lead in cassava ethanol projects and farmers in the region are keen to increase yields. Although some members of the development community would like food security to be pursued for food security’s sake, research on new crop varieties very often comes from cooperation between research institutions, donors and big agricultural companies.

In Thailand, the world’s largest cassava producer, international agricultural institutions across three continents have come together to find a solution to the problem caused by the cassava mealybug. Thailand’s Agriculture Ministry worked on a solution with the IITA office in Benin and Colombia’s Centro Internacional de Agricultura Tropical (CIAT). Rather then spray harmful pesticides across vast swathes of the country, the Thai scientists and their partners decided in July that using wasps, the mealybug’s natural predators, was the least intrusive intervention.

To modify or not?

The main fault-line in the debate over agriculture research is the issue of genetic modification (GM). International GM initiatives like BioCassava Plus, backed by the Bill and Melina Gates Foundation, are seeking to make traditional crops longer-lasting and more nutritious. Other institutions are investing in alternative means to improve harvests. Along with its work in Zanzibar and Thailand, the IITA is working through more traditional means to boost crop resistance and collect samples of indigenous crop varieties to provide a bigger pool for future breeding programmes.

Uganda’s Plant Genetic Resources Centre supports GM research and is working on creating new varieties of rice which will take the best characteristics of hardy indigenous varieties. This is worrying policymakers in the East African Community because the regional grouping does not have a common policy on GM produce.

Wider partnerships among research institutions and sustained drives to eradicate crop diseases are the most reliable means to improve crop yields and treat diseases which undermine economic livelihoods and food security. The most recent advances in creating robust and high-yielding varieties of banana, cassava, maize and rice show that African farmers can be better armed to fight natural threats, so long as the technological advances are met with improvements in access to information, finance and improved seeds.