在线国产一区二区_成人黄色片在线观看_国产成人免费_日韩精品免费在线视频_亚洲精品美女久久_欧美一级免费在线观看

您現在的位置: > Language Tips > Audio & Video > Special Speed News  
 





 
Ever wonder where seedless fruits come from?
[ 2007-01-04 09:39 ]

This is the VOA Special English Agriculture Report.

These days, if we hear about two different plants being combined, the first thing we think of might is modern biotechnology. But the low-technology process of grafting remains an extremely important form of genetic engineering in agriculture.

Many kinds of plants are grown not from seeds but from pieces cut from existing plants. Farmers cut branches or buds, young growths, from one plant and place them on a related kind of plant.

The branch or bud that is grafted is called a scion [pronounced SY-uhn]. The plant that accepts the graft is called the root stock.

Over time, the parts from the two plants grow together. The grafted plant begins to produce the leaves and fruit of the scion, not the root stock.

A graft can be cut in several ways. A cleft graft, for example, requires a scion with several buds on it. The bottom of the scion is cut in the shape of the letter V. A place is cut in the root stock to accept the scion.

The scion is then securely placed into the cut on the root stock. Material called a growth medium is put on the joint to keep it wet and help the growth.

Grafting can join scions with desirable qualities to root stock that is strong and resists disease and insects. Smaller trees can be grafted with older scions.

The United States Environmental Protection Agency says producing stronger plants by grafting can reduce the need to use pesticides.

Agriculture could not exist as we know it without grafting. Many fruits and nuts have been improved through this method. Some common fruit trees such as sweet cherries and McIntosh apples have to be grafted.

Bing cherries, for example, are one of the most popular kinds of cherries. But a Bing cherry tree is not grown from seed. Branches that produce Bing cherries must be grafted onto root stock. All sweet cherries on the market are grown this way.

And then there are seedless fruits like navel oranges and seedless watermelons. Have you ever wondered how farmers grow them? Through grafting.

The grapefruit tree is another plant that depends on grafting to reproduce. Grapes, apples, pears and also flowers can be improved through grafting.

In an age of high-technology agriculture, grafting still holds an important place.

graft : to unite (a shoot or bud) with a growing plant(嫁接)

點擊進入更多VOA慢速


(來源:VOA  英語點津姍姍編輯)

 
 
相關文章 Related Stories
 
Investment in agriculture urged on World Food Day Tapping into Vermont's maple syrup industry
Genetic map points way to an improved honey bee
         
 
 
 
 
 
         

 

 

 
 

48小時內最熱門

     

本頻道最新推薦

     
  The Lake House《觸不到的戀人》(精講之四)
  Former US President Ford laid to rest in Michigan
  Ever wonder where seedless fruits come from?
  Two new designs to help the poor countries
  Trends of America in this year

論壇熱貼

     
  周星馳的一句臺詞再譯(c-e)
  “早生貴子”英語怎么說
  日常口語趣味翻譯(It's fun!)
  how to say "彩鈴" in English?
  “天壤之別”英語怎么說?
  翻譯:老鄉見老鄉,兩眼淚汪汪




主站蜘蛛池模板: 最新日韩在线观看视频 | 99视频在线 | 亚洲日本韩国欧美 | 久久综合久色欧美综合狠狠 | 中文字幕亚洲欧美日韩在线不卡 | 日韩免费在线观看视频 | 日一区二区 | 欧美日韩一区二区视频在线观看 | 日韩精品av一区二区三区 | 欧美精品在线一区二区三区 | 日韩高清成人 | 国产亚洲欧美精品永久 | 亚洲午夜精品一区二区三区 | 国产高清免费视频 | 国产女人和拘做受在线视频 | 久久亚洲一区二区 | 日韩精品一区二区三区第95 | 亚洲国产精品99久久久久久久久 | 在线播放亚洲 | 国产一区二区视频在线播放 | 日本精品视频在线播放 | gav成人免费播放视频 | 久久国产香蕉视频 | 久久国产精品一区二区 | 日韩性视频 | 北条麻妃国产九九九精品小说 | 日本一区二区成人 | 国产日产一区二区三区久久久久久 | 欧美日韩综合精品 | 亚洲视频在线观看网址 | 一区二区精品 | 欧美视频一区 | 999视频在线免费观看 | 国内精品久久久久久中文字幕 | 国产h视频在线观看 | 国产精品久久久久久av公交车 | 国产视频亚洲精品 | 色接久久| 国产乱码精品一区二区三区手机版 | 夸克满天星在线观看 | 日韩一 |