I'm Faith Lapidus with the VOA Special English Agriculture Report.

We often think of agriculture as planting seeds and harvesting crops. But many crops do not come from seeds. Many kinds of trees and plants are grown from pieces cut from existing trees and plants. This is calledgrafting.

Farmers cut branches or young growths, called buds, from one plant and place them on a related kind of plant. The branch or bud that is grafted is called ascion(pronounced SY-uhn). The plant that accepts the graft is called theroot 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 agrowth mediumis 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 American Environmental Protection Agency says grafting can reduce the need to use pesticides on crops. The E.P.A. found that grafting stronger plants costs less than using chemicals. Also, poisons can be dangerous to people and the environment.

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 assweet cherriesandMcIntosh appleshave 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 likenavel orangesand seedless watermelons. Have you ever wondered how farmers grow them? The answer is: through grafting.

Thegrapefruittree 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 is a low-technology method that remains extremely important.

This VOA Special English Agriculture Report was written by Mario Ritter. Our reports are on the Web at voaspecialenglish.com. I'm Faith Lapidus.

grafting: 嫁接法；[医]移植法

scion: （为嫁接剪下的）嫩芽，小枝

root stock: 根茎, 主根

growth medium: 培养基

sweet cherry: a large, widely cultivated deciduous tree (Prunus avium) of the rose family, native to Eurasia, having red-brown birchlike bark, white flowers, and sweet edible fruit(洋樱桃树：被广泛栽种的蔷薇科大型落叶树，原产于欧亚大陆，被称为欧洲甜樱桃）

McIntosh apple: 麦金托什苹果：美国人麦金托什培育的一种晚熟的红苹果，又作McIntosh Red。

Bing cherry: a variety of cherry with juicy, sweet, deep red to nearly black fruit（槟樱桃：多汁味甜、几近黑色的深红果实）

navel orange: a sweet, usually seedless orange having at its apex a navellike formation enclosing an underdeveloped fruit（脐橙：一种通常无籽的甜橘子，果实中包着一个肚脐形状的未发育好的水果）

grapefruit: a tropical or semitropical evergreen (Citrus paradisi) cultivated for its edible fruit（葡萄柚）