www射-国产免费一级-欧美福利-亚洲成人福利-成人一区在线观看-亚州成人

This is the VOA Special English Agriculture Report.

Scientists have worked for 12 years to develop what they call Green Super Rice. They say several varieties should be available to farmers about two years from now in parts of Asia and Africa.

The "green" in Green Super Rice means environmentally friendly. Researchers say it will produce at least as much grain as other rice plants but with fewer inputs. "Super" means the rice is designed to better resist droughts, floods, salty water, insects and disease.

The developers of Green Super Rice did not use genetic engineering. Instead, they mated hundreds of varieties of rice. That way they avoided the costs as well as the problems connected with getting permission to plant genetically engineered crops.

The project involves the world's largest rice collection, the International Rice Research Institute in the Philippines. It also involves the Chinese Academy of Agricultural Sciences. And it includes farmers in eight countries in Asia and eight in Africa.

Modern rice plants produce two to three times more grain than was possible before the 1960s. But they also require large amounts of water, chemical fertilizers and pesticides.

In the 1960s, the International Rice Research Institute developed "miracle rice" for Asia. Scientists created high-yielding crops that produced bigger harvests in what became known as the Green Revolution. It prevented widespread hunger.

But critics say modern rice plants require too much water and too much use of chemicals that can hurt the environment. And farmers may be too poor to buy chemical fertilizers and pesticides.

Anna McClung heads a rice-breeding center for the United States Agriculture Department. She says combining many different genes into one plant without genetic engineering requires a lot of plant breeding. Ms. McClung praises the researchers working on Green Super Rice.

ANNA McCLUNG: "The magnitude of what they are doing is really quite unique and tremendous."

Another rice researcher, Jan Leach at Colorado State University, says scientists can find valuable qualities hidden in the rice genome. A genome contains all of the genetic information about an organism.

JAN LEACH: "Many of the traits are present, but they are not turned on until you get them into the right genetic background, or sometimes in the right environment."

Researchers on the Green Super Rice project continue to combine desirable traits into new varieties to help farmers produce more with less.

And that's the VOA Special English Agriculture Report. You can also watch captioned videos on YouTube at VOA Learning English. I'm Karen Leggett.

Related stories:

Integrated pest management can increase crop production

Plan to protect food supply against global warming announced in Rome

World food prices expected to stay high or keep rising

Phone call about fertilizer could be a big help to Philippine rice farmers

（來源：VOA 編輯：崔旭燕）