Farmers in East Africa Struggle Against Cassava Disease
07 June 2010
A woman collects cassava leaves in eastern Kenya
This is the VOA Special English Agriculture Report.
About eight hundred million people in Africa, Asia and South America eat cassava. The plant is a major source of food energy and a major food security crop. It can survive in poor soil and without much water. Also, the root can stay in the ground for as long as three years, so it can be harvested as needed.
But in East Africa the plant is under attack. Cassava brown streak disease is a more destructive form of cassava mosaic. The mosaic has been active in East Africa for about one hundred years. It limits plant growth. But brown streak can destroy a crop. The virus was identified in Uganda in two thousand four and has spread fast in areas extending from Lake Victoria.
So far, brown streak has not jumped to Nigeria, the world's largest producer of cassava. But it threatens more than thirty million tons a year of production in East Africa. In some areas of Uganda, rates of brown streak reached more than eighty-five percent in two thousand five and two thousand eight.
Claude Fauquet is a scientist at the Donald Danforth Plant Science Center in Saint Louis, Missouri. He says a few varieties of cassava can resist brown streak, but these are not the kinds Africans like. He is working to develop disease-resistant plants, but he says it will probably take five years.
最新
2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25