This is the VOA Special English Agriculture Report.
这里是美国之音慢速英语农业报道。
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.
非洲、亚洲和南美大约有8亿人口是用木薯。木薯是食品能源的主要来源，也是保障粮食安全的主要作物。木薯可以在贫瘠缺水的土壤生长。同时，木薯的根在土壤中存活时间长达3年之久，因此可以根据需要收获。
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.
但是在东非这种作物正遭受攻击。木薯褐条病比木薯花叶病更具破坏性。花叶病已在东非活跃了大约100年时间，它会限制作物生长，但褐条斑病却能摧毁作物。这种病毒2004年首次在乌干达地区被确认，随后从维多利亚湖地区迅速蔓延。
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.
到目前为止，褐条病还没有传播到全球木薯最大产地--尼日利亚。但已经威胁到东亚地区每年超过3000万吨的产量。在乌干达的一些地区，2005年和2008年，褐条病的感染比率已超过85%。
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.
Claude Fauquet是密苏里州圣路易斯市唐纳德丹佛植物科学中心（Donald Danforth Plant Science Center，DDPSC）的科学家。他称，有几个品种的木薯可以抵抗褐条病，但都不是非洲人喜欢的品种。他正致力于开发抗病植株，但他表示这可能需要五年的时间。
Loss of cassava crops could lead to hunger. And hunger can lead to migration and conflict. About fifty million dollars is coming from the Gates Foundation, the Monsanto Fund and the United States Agency for International Development. But Claude Fauquet says much more is needed to fight the disease.
木薯作物的损失可能会导致饥荒，而饥荒会导致迁徙和冲突。盖茨基金，孟山都基金和美国国际开发署已经提供了5000万美元的资助。但Claude Fauquet表示，防治灾害还需要更多资金。
Brown streak can be hard to identify in the field. Irregular yellow spots may appear on lower leaves. But farmers sometimes do not find the disease until they cut open a cassava. If there is only a small amount of rot, the dead material can be cut away. But if the disease has progressed, the whole root is ruined.
种在地里的木薯如果患褐条病很难被鉴定出来。植株下部的叶片可能会出现不规则黄斑，但有时农民直到切开木薯才能发现这种病害。如果只是小部分腐烂，可以将坏死的部分切除。但是如果病害已经蔓延，整个根就都毁了。
Scientists partly blame whiteflies for spreading the disease from plant to plant. Brown streak also spreads if farmers sell or give away cuttings of infected plants.
科学家将褐条病在植株间的传播部分原因归咎于粉虱。农民出售或随意处置感染的植株切块，也会导致褐条病传播。
Cassava has many food uses but the plant is not safe to eat unless it is specially prepared. It must be processed through methods like boiling, grinding or fermenting. A substance that can produce deadly levels of cyanide when eaten must be removed.
木薯具有多种食品用途，但必须经过特殊处理方可安全食用。它必须通过煮沸、研磨、或者发酵等方法加工。当食用时，一种可能会产生致命氰化物的物质必须被去除。