Next Steps
Meanwhile, experts are still trying to breed aflatoxin-resistant varieties of corn and other crops. Despite years of effort, they have yet to produce a single commercially viable cultivar. But Robert Brown, a research plant pathologist with the Agricultural Research Service, says he and his collaborators have bred several potentially viable varieties from aflatoxin-resistant samples collected in the United States and Africa. According to Brown's unpublished data, aflatoxin levels are nearly 87-fold lower in the resistant varieties than in nonresistant corn kernels.
USAID's Bowman says that along with biocontrol, resistance breeding remains an important part of strategies to minimize aflatoxin exposure in the developing world. The trick, Payne says, is to breed resistant lines with other commercially viable attributes, such as high yield.
The lack of consistent standards within African countries and elsewhere in the world is also problematic, Nelson adds. PACA and other groups are working to support development of harmonized standards in Africa, but selecting a shared value is a complex and arduous prospect. "Countries don't want to be held to a standard they don't think they can achieve," Nelson explains.
Still, Stinson says, aflatoxins are a major trade issue because some 15 African countries have aflatoxin limits above which crops are not allowed into the country. "Individual countries need to establish standards, train farmers, [and] work through agricultural extensions to control aflatoxin," she says. "Each country with an aflatoxin problem needs an aflatoxin action plan."
Ultimately, tackling aflatoxins in the developing world will require a profound social transformation, Cardwell emphasizes. "We need a system that makes aflatoxin control worthwhile," she says. "Technically, it's a no-brainer, but from a social and development context it's extremely complex."