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 called grafting.
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 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 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 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? The answer is:
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 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. |