Sweet and juicy, pears are a wonderful snack or dessert. But where do they come from?




Дата канвертавання25.04.2016
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Pears

Liza Ronholdt

Sweet and juicy, pears are a wonderful snack or dessert. But where do they come from?

Pears are a pome fruit in the family Rosaceae. There are many species of pear, but the two most common and important are Pyrus communis (European pear), and Pyrus pyrifolia (Asian pear). They can be long or round, green, yellow, red, orange, or brown.




History

Pears first originated in Europe and Asia. They were first cultivated form wild varieties that grew during prehistoric ages. The ancient Romans knew of only 6 varieties, but by the late 1800’s there were at least 850 known cultivars.



Propagation
Fruits that are grown for certain characteristics cannot be grown from seed. The fruits of the tree that produced the seed would have been pollinated by a different plant, and would produce different characteristics on the next generation of fruit. Therefore, fruits must reproduce asexually.
Grafting is the best way to propagate pear trees. Grafting is done by cutting a branch off of one plant (called a scion) and attaching it to an entirely different plant. Pears can also be propagated by chip budding or T-budding onto compatible rootstocks. This is done by cutting a bud off of a desired pear plant and slipping it into a notch cut into the bark of the rootstock. In both grafting and budding, the new plant part must be held secure with tape or grafting wax while the plant heals the wound. A humid environment also helps the plant to heal.

There are many reasons why almost all pears are propagated by grafting. Pears are not hardy for cold weather, and there are only a few cultivars that can be grown in the northern states. Also, pear trees tend to be very tall, and are often grafted onto rootstocks that make them shorter. Some rootstocks can also give pears resistance to certain diseases, such as fire blight, or help them adapt to certain types of soil.


Grafting is not as easy as just connecting two plants together and taping them up. The cambium layers must be aligned in order for the plant to continue its uptake of water while the grafting wound heals. The scion and the rootstock must also be compatible with each other. Typically, plants of the same genus and species will work well together, and oftentimes having the same species is enough to unite two plants.
Most pears can be grafted onto the rootstock of another pear, but sometimes quince rootstocks are used. A quince is another type of pome fruit in the family Rosaceae. Usually these are used as rootstocks when a dwarfing is the desired effect. Certain pear scions are not compatible with quince rootstocks. In this case, an interstock would be used. This is a piece of stem from a third type of tree, which is compatible with both the scion and the rootstock. It acts as a bridge for the graft. For example, the ‘Old Home’ variety of pear is often used as an interstock when ‘Bartlett’ pears are grafted onto quince rootstocks.

However, quince tends to have a shallow root system, and is not suitable for all types of soils and climates.


Another use for grafting is to apply several different varieties of pear to one tree. This can be useful for homes that have small yards. In some cases, several different types of fruit can be grafted to the same tree.

Once you have achieved a successful graft, it is very important to take good care of your pear tree. Good cultural practices, such as pruning, will help to ensure a happy tree, and eventually a delicious snack!


SOURCES



Pictures



www.usapears.com

www.asmallworkofart.com/pear.htm

www.kappusfarms.com/pear.html

www.free-graphics.rink/Fruits/pears4html

Other Sources



www.eurofreehost.com

www.thefruitpages.com

www.uga.edu/fruit/pear.htm

www.ext.nodak.edu/extpubs/plantsci/hortcrop/h327w.htm


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