在线词典,在线翻译

嫁接技术为何依然适应农业发展

所属:听力板块 阅读:7141 次 评论:0 条 [我要评论]  [+我要收藏]

小编摘要:嫁接是一种从现存植物,而不是从种子繁殖植物的方法。从一种植物切下来的枝或芽被嫁接到另一种相近植物上。嫁接上去的枝或芽被称为接穗。被嫁接的植物体被称为砧木。

Why Grafting Still Fits Nicely Into Agriculture

Grafting is a way to produce plants from pieces of existing plants instead of seeds.

Branches or buds are cut from one plant and placed on a related kind of plant. The branch or bud that is grafted is called the scion. The plant that accepts the graft is called the rootstock.

Grafting can join scions with desirable qualities to rootstock that is strong and resists disease and insects.

A graft can be cut several ways. One way is a cleft graft. It requires a scion with several buds on it. The bottom of the scion is cut in the shape of the letter V.

The scion is then securely placed into a cut on the rootstock. Material called a growth medium is put on the joint to keep it from getting dry and to help the two plants grow together.

Many fruits and nuts have been improved through grafting. Flowers can also be improved this way.

Some common fruit trees such as sweet cherries and McIntosh apples have to be grafted. Grafting is also used to produce seedless fruits like navel oranges and seedless watermelons.

Grafting continues to hold an important place in agriculture even in an age of modern genetic engineering.

Recently we told you about a study of genetically engineered crops and how they have affected farming in the United States. The study found that many farmers have better harvests, better weed control and fewer losses from insect damage compared to traditional crops.

Our story brought a number of comments, including this one from Odalberto Domingos Casonatto in Brazil. He wrote that in his town the population depends on agriculture and transgenic crops. He says it is true that such crops can have higher output with less cost, but added:

No one knows the consequences that will have on soil fertility and the human body. Only the future will tell us the truth about transgenic food.

Christian in France expressed a different concern, saying: The big problem of the transgenic seeds is that they are the monopoly of big companies. The small farmers cannot reproduce any more seeds by themselves.

And Joom from Thailand wrote: I don't care where the crops come from, natural plants or genetic engineering, as long as we can produce food enough for people.

You can comment on our stories and find transcripts, MP3s and podcasts at 51voa.com. You can also join us on Facebook and Twitter at VOA Learning English.

标签:voa special
0
2012-06-30 22:44 编辑:pliny
分享到:
关注海词微博:
发表评论:
表达一些您的想法吧!已有0条评论>>
登录,再发表评论
文明上网,理性发言!
您可能还感兴趣的文章:
  • [听力板块]美国最流行的小孩名字

    2010年美国出生的小孩有一个优先的机会被取名为“贝拉”或“爱德华”。这两个名字分别是10大最受欢迎的女孩和男孩名字中的一个。无独有偶,这恰恰是广受欢迎的描述吸血鬼的暮光系列的小说和电影
  • [听力板块]自然博物馆的一场生动科学展览

    户外、露天似乎是学习自然科学的天然场所。在南加州这种人们更喜欢户外的地方,它也极具意义。目前,洛杉矶县自然历史博物馆正为游客把展览从室内搬到户外。