Fighting Witchweed in African Sorghum

Fighting Witchweed in African Sorghum
Scientists develop herbicide-resistant seeds that can kill the parasitic plant. Transcript of radio broadcast:
23 June 2008

This is the VOA Special English Development Report.

Farmers in Africa call the striga plant by the name witchweed. It grows a pleasant looking purple flower. But it attacks many crops in the grass family. Witchweed is among the few flowering weeds that act as parasites on other plants.

Every year it causes six to seven billion dollars in damage to African grain sorghum. Sorghum is important to the local food supply. The witchweed steals water and nutrients from the roots and attacks the sorghum with a poisonous substance.

Now, scientists say they have produced seeds that can protect sorghum crops from witchweed.

Kassim Al-Katib is a weed expert at Kansas State University in the United States. Mitch Tuinstra is a genetics and plant-breeding expert formerly at Kansas State but now at Purdue University in Indiana.

To deal with witchweed, they developed special sorghum-seed genes. These genes can accept carefully chosen chemical herbicides without being harmed. The researchers placed the herbicides on the sorghum seeds. Kassim al-Katib said the seeds kill the witchweed as the sorghum grows.

Mitch Tuinstra directed greenhouse tests of the seeds in the Netherlands in two thousand five and two thousand six. Similar studies took place in field trials in Mali and Niger. These studies showed the treatment to be highly successful.

Mitch Tuinstra recently returned from Africa, where he met with agriculture experts. They are working to develop local kinds of sorghum that employ the genes. The project is a collective research program under the United States Agency for International Development.

Witchweed has another unusual quality. It requires chemical signals from sorghum seeds to grow. If no sorghum seeds are present, the witchweed seeds can lie under the soil for years. The seeds begin to grow only when they receive the needed chemical signals.

Witchweed seed capsules can hold four hundred to five hundred seeds. Winds and rain spread the parasite. The plant can reduce a farmer's crop. Or it can completely destroy many hectares of grain. Witchweed is very difficult to remove after it invades an area.

Damage from the parasite is worst in dry soil with low fertility. It often strikes farmers who work the poorest land. This can mean disaster for people who already do not have enough to eat.

And that's the VOA Special English Development Report, written by Jerilyn Watson.

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战斗witchweed在非洲高粱
科学家研制出抗除草剂的种子可以杀死寄生的植物。全文电台广播：
2008年6月23日

这是美国之音特别英语发展报告。

农民在非洲致电striga植物的名称witchweed 。它生长愉快的期待紫色的花。但它的攻击，许多作物在基层的家庭。 witchweed是其中的少数开花的杂草，该法作为寄生虫对其他植物。

每年造成6至7亿美元，在损害非洲粮食高粱。高粱是很重要的向当地的食物供应。该witchweed次抢断，水分和养分，从基层和攻击高粱与有毒物质。

现在，科学家说，他们曾制作的种子可以保护高粱作物从witchweed 。

卡西姆基地- katib是一个杂草专家在堪萨斯州立大学在美国。米奇tuinstra是一个遗传学和植物育种专家以前在堪萨斯州，但现在在普渡大学在印第安纳。

处理witchweed ，他们研制的特别高粱种子的基因。这些基因可以接受的慎重选择化学除草剂，没有受到伤害。研究人员把除草剂对高粱种子。卡西姆基地- katib说，种子杀死witchweed作为高粱增长。

米奇tuinstra针对温室试验的种子，在荷兰，在2000五和2000 6 。类似的研究，发生在实地试验中，马里和尼日尔。这些研究显示，治疗非常成功。

米奇tuinstra最近返回来自非洲，他在那里会见了农业专家。他们致力于发展本地种高粱雇用的基因。该项目是一项集体研究计画下，美国国际开发署。

witchweed有另一个不寻常的品质。它需要的化学信号，从高粱种子增长。如果没有高粱种子是目前， witchweed种子的谎言下，土壤年。种子开始成长，只有当他们获得所需要的化学信号。

witchweed种子胶囊可容纳400至500种。风和雨传播寄生虫。植物可以减少农民的作物。或者它可以完全毁灭很多公顷的粮食。 witchweed是非常困难的，以消除后，它侵占的一个领域。

损害由寄生虫是最严重的干土，与低生育水平。它常常罢工，农民谁工作最贫穷的土地。这可能意味着灾难的人谁已经没有足够的食品。

这是该美国之音特别英语的发展报告，写jerilyn沃森。