VOA慢速英语 2008 1104a

This is the VOA Special English Agriculture Report.
　
Cotton plants

Bollworms are a traditional threat to cotton crops. Young ones feed on the boll, the part of the cotton plant that contains the seeds.

A bacterium¹ known as Bt is able to kill bollworms and some other pests. Bt is short for Bacillus thuringiensis. It was discovered in the early twentieth century. Farmers began using Bt as a natural pesticide².

Then, in the nineteen nineties, researchers found a way to grow cotton plants that contain a Bt gene³. The genetically⁴ modified cotton plant produces toxins⁵ that kill bollworms. Farmers around the world are now growing an estimated fourteen million hectares of Bt cotton.

Cotton bollworms also attack other crops. But scientists in China recently reported that Bt cotton may help suppress bollworm in other crops growing nearby.

The study involved crops grown in six provinces of northern China between nineteen ninety-two and two thousand seven. The study area contained three million hectares of cotton and twenty-two million hectares of corn, peanuts, soybeans and vegetables.

The researchers say the study suggested that Bt cotton not only controls bollworm on the transgenic cotton, but also may reduce its presence on other crops. And that reduction, they say, may decrease the need for insecticide sprays in general.

But the researchers also pointed⁶ out concerns. They say bollworms could develop resistance to the cotton plants designed to resist them. And they noted⁷ that insects called mirids have become "key pests" of cotton in China. They said this is because of a decrease in pesticide use made possible by Bt cotton.

The researchers say they do not believe that Bt cotton alone can solve all insect problems. Instead, they say farmers in China should consider it just one part of pest management systems.

Kong-Ming Wu of the Chinese Academy of Agricultural Sciences in Beijing led the study. The findings appeared in Science magazine.

A British group, the Institute of Science in Society, said the findings were presented in a way that could mislead readers. The group noted that the only part of the study available online at no cost, a short abstract, said nothing about the concerns.

And that’s the VOA Special English Agriculture Report, written by Jerilyn Watson with additional reporting by Jessica Berman. I’m Bob Doughty⁸.

 

1 bacterium   

n.(pl.)bacteria 细菌

参考例句：

• The bacterium possibly goes in the human body by the mouth.细菌可能通过口进入人体。
• A bacterium is identified as the cause for his duodenal ulcer.一种细菌被断定为造成他十二指肠溃疡的根源。

2 pesticide   

n.杀虫剂，农药

参考例句：

• The pesticide was spread over the vegetable plot.菜田里撒上了农药。
• This pesticide is diluted with water and applied directly to the fields.这种杀虫剂用水稀释后直接施用在田里。

3 gene   

n.遗传因子，基因

参考例句：

• A single gene may have many effects.单一基因可能具有很多种效应。
• The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。

4 genetically   

adv.遗传上

参考例句：

• All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
• Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物

5 toxins   

n.毒素( toxin的名词复数 )

参考例句：

• The seas have been used as a receptacle for a range of industrial toxins. 海洋成了各种有毒工业废料的大容器。
• Most toxins are naturally excreted from the body. 大部分毒素被自然排出体外。 来自《简明英汉词典》

6 pointed   

adj.尖的，直截了当的

参考例句：

• He gave me a very sharp pointed pencil.他给我一支削得非常尖的铅笔。
• She wished to show Mrs.John Dashwood by this pointed invitation to her brother.她想通过对达茨伍德夫人提出直截了当的邀请向她的哥哥表示出来。

7 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

8 doughty   

adj.勇猛的，坚强的

参考例句：

• Most of successful men have the characteristics of contumacy and doughty.绝大多数成功人士都有共同的特质：脾气倔强，性格刚强。
• The doughty old man battled his illness with fierce determination.坚强的老人用巨大毅力与疾病作斗争。