VOA标准英语2010年-Harmless Fungus Protects African Crops

Possible solution to Kenya's fatal aflatoxin outbreaks

Steve Baragona | Washington, DC 10 June 2010
 

People sharing and distributing aflasafe on a farm in Nigeria.

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International Institute of Tropical Agriculture

As Kenya suffers with another outbreak of deadly aflatoxin contamination, scientists say a harmless version of the fungus² that produces the toxin¹ could be a powerful ally in preventing future outbreaks.

Aflatoxin is a natural poison produced by a fungus that grows on maize³, cassava, ground nuts, and other crops. The mold thrives in hot, humid conditions.

At high doses, aflatoxin causes liver damage that can be fatal. A 2004 outbreak in Kenya killed at least 125 people.

This month, the Kenyan government warned that at least one person had died and 2.3 million bags of maize were contaminated with the poison.

Aflatoxin is dangerous even at low doses. It can cause cancer, stunt⁴ children's growth, and weaken the immune system.

Men distributing aflasafe to farmers in Nigeria.
Giving the good guys a head start

Some of the strains found in Kenya produce especially high levels of aflatoxin. But Peter Cotty, a plant disease expert with the U.S. Department of Agriculture, says there also are naturally occurring strains of the fungus in Kenya that produce no aflatoxin at all.

"They occur already in the villages. They're just at low frequency," he says. "We can use techniques to find these fungi⁵, and we can release them in a manner that allows them to out-compete these very high toxin-producers."

Cotty and his colleagues help the harmless fungi compete by giving them a head start over the bad guys. They grow the good guys on grains such as barley⁶ or sorghum⁷ that are sterilized⁸ so they don't sprout⁹. When farmers spread these grains among their crops, the harmless mold proliferates¹⁰, feeding on dead plants and insects. It will "multiply and spread throughout the field and displace the toxin producers," he says.

Fighting fungus with fungus

Cotty and colleagues at the Nigeria-based International Institute of Tropical Agriculture (IITA) have registered a product called Aflasafe with Nigerian regulators. In field tests last year, farmers who used the grains coated with harmless fungi reduced aflatoxin contamination by an average of 80 percent.

U.S. farmers are also fighting fungus with fungus. For example, cotton growers need to ward¹¹ off aflatoxin contamination or they won't be able to sell the seeds for animal feed. Michael Braverman at Rutgers University manages a program helping¹² scientists register new natural crop protection products with U.S. regulators. He says cotton growers in the southwestern state of Arizona use the same method being tested in Nigeria.

"It's effective enough that the growers in Arizona have built their own facility to manufacture this product," he says. "They are not only consumers of the product, they are the official body that owns the registration¹³."

Peter Cotty and the IITA are now looking for a partner to bring the technology to farmers in Kenya, where aflatoxin contamination is taking a terrible toll¹⁴ on people and the economy.
 

1 toxin   

n.毒素，毒质

参考例句：

• Experts have linked this condition to a build-up of toxins in the body.专家已把这一病症与体内毒素的积累联系起来。
• Tests showed increased levels of toxin in shellfish.检验表明水生有壳动物的毒素水平提高了。

2 fungus   

n.真菌，真菌类植物

参考例句：

• Mushrooms are a type of fungus.蘑菇是一种真菌。
• This fungus can just be detected by the unaided eye.这种真菌只用肉眼就能检查出。

3 maize   

n.玉米

参考例句：

• There's a field planted with maize behind the house.房子后面有一块玉米地。
• We can grow sorghum or maize on this plot.这块地可以种高粱或玉米。

4 stunt   

n.惊人表演，绝技，特技；vt.阻碍...发育，妨碍...生长

参考例句：

• Lack of the right food may stunt growth.缺乏适当的食物会阻碍发育。
• Right up there is where the big stunt is taking place.那边将会有惊人的表演。

5 fungi   

n.真菌，霉菌

参考例句：

• Students practice to apply the study of genetics to multicellular plants and fungi.学生们练习把基因学应用到多细胞植物和真菌中。
• The lawn was covered with fungi.草地上到处都是蘑菇。

6 barley   

n.大麦，大麦粒

参考例句：

• They looked out across the fields of waving barley.他们朝田里望去,只见大麦随风摇摆。
• He cropped several acres with barley.他种了几英亩大麦。

7 sorghum   

n.高粱属的植物，高粱糖浆，甜得发腻的东西

参考例句：

• We can grow sorghum or maize on this plot.这块地可以种高粱或玉米。
• They made sorghum into pig feed.他们把高粱做成了猪饲料。

8 sterilized   

v.消毒( sterilize的过去式和过去分词 )；使无菌；使失去生育能力；使绝育

参考例句：

• My wife was sterilized after the birth of her fourth child. 我妻子生完第4个孩子后做了绝育手术。 来自辞典例句
• All surgical instruments must be sterilized before use. 所有的外科手术器械在使用之前，必须消毒。 来自辞典例句

9 sprout   

n.芽，萌芽；vt.使发芽，摘去芽；vi.长芽，抽条

参考例句：

• When do deer first sprout horns?鹿在多大的时候开始长出角？
• It takes about a week for the seeds to sprout.这些种子大约要一周后才会发芽。

10 proliferates   

激增( proliferate的名词复数 )； （迅速）繁殖； 增生； 扩散

参考例句：

• The tumor proliferates, invades the uterine wall, and disseminates to remote organs. 肿瘤增殖，侵犯到子宫壁，并播散至远处的脏器。
• We should expect the services to be more interdependent as digitization proliferates. 因为数字化技术在扩散，我们殷切希望各军种更好地相互依赖。

11 ward   

n.守卫，监护，病房，行政区，由监护人或法院保护的人（尤指儿童）；vt.守护，躲开

参考例句：

• The hospital has a medical ward and a surgical ward.这家医院有内科病房和外科病房。
• During the evening picnic,I'll carry a torch to ward off the bugs.傍晚野餐时，我要点根火把，抵挡蚊虫。

12 helping   

n.食物的一份&adj.帮助人的，辅助的

参考例句：

• The poor children regularly pony up for a second helping of my hamburger. 那些可怜的孩子们总是要求我把我的汉堡包再给他们一份。
• By doing this, they may at times be helping to restore competition. 这样一来, 他在某些时候,有助于竞争的加强。

13 registration   

n.登记，注册，挂号

参考例句：

• Marriage without registration is not recognized by law.法律不承认未登记的婚姻。
• What's your registration number?你挂的是几号？

14 toll   

n.过路(桥)费；损失，伤亡人数；v.敲(钟)

参考例句：

• The hailstone took a heavy toll of the crops in our village last night.昨晚那场冰雹损坏了我们村的庄稼。
• The war took a heavy toll of human life.这次战争夺去了许多人的生命。