Lemon belongs to the Rutaceae family, the orange subfamily and the citrus genus.
In addition to lemon, this genus includes mandarin, orange, citron, brigaradia, grapefruit, etc.
According to the established classification, all these fruits are called citrus.
All citrus fruits, including lemon,are evergreens.
In the cold season, they do not shed leaves: there is no outflow of nutrients in them,
as in other trees, but their constant accumulation takes place. Thus, the leaves are like
it would be a storage of important elements for the plant, which are spent exclusively on the growth of new leaves, shoots and branches, as well as on fruiting. It is very easy to distinguish a healthy tree from a sick one: a healthy lemon tree has an abundance of green healthy leaves that are actively involved in the physiological processes of growth.
Lemon leaf lives, as a rule, from two to three years. The leaves crumble gradually as they age.
If a sharp fall of foliage is detected, this indicates that the growth mechanism is disrupted and the plant
needs fertilizing with fertilizers. If a tree loses leaves, it negatively affects its fruiting.
The root system of citrus fruits has one interesting feature that should be given a little attention.
The roots of most plants are a web of root hairs through which they draw water and nutrients from the ground.
Citrus fruits, including lemon, do not have such. They are replaced by special soil fungi located on the roots of the tree
in the form of thickenings, called mycorrhiza. The relationship of fungi and wood is based on symbiosis:
the fungus receives nutrients from the tree, and itself, in turn, provides the plant with the consumption
of everything necessary for growth. The capriciousness of the symbiotic fungus is largely determined by the behavior of the tree itself.
The fact is that mycorrhiza is quite sensitive to temperature and other factors.
For example, it does not tolerate the lack of moisture and lack of air when the earth is too dense.
At temperatures above 50 and below 7 °With she dies. Flower buds are formed mainly in spring.
Buds develop from the moment of appearance for a month and only then bloom. Flowering lasts for several days,
during which pollination takes place. A few days after the petals fall, the rudiments of the fetus are formed.
Often, at the first fruiting, many ovaries are formed, but since the young tree cannot yet properly support them,
many ovaries crumble before reaching maturity.
Lemons are perhaps the most capricious of citrus fruits: temperatures below 7 ° C are fatal for them, and when negative
temperature causes various disturbances of metabolic processes. Thus, lemon he is very whimsical, but this quality is more than compensated by the valuable substances that he possesses.
Distribution
Traditionally, the tropical and subtropical regions of Southeast Asia and India are considered the homeland of citrus fruits.
Lemon is no exception. In these territories, nature has created ideal conditions for its life:
the combination of a suitable amount of light, heat and moisture allows the tree to bear fruit all year round - flowering is observed 2-3 times a year.
As you can see, the conditions in which the lemon culture originated are ideal, but this does not mean at all'
that the area of this citrus has not spread to other parts of the world.
Citrus fruits in general have been cultivated in Asia for more than one century, even more than one millennium.
For example, the Chinese did not limit themselves to just simple cultivation of crops and proved themselves as skilled breeders.
Back in the first centuries BC, new lemon varieties were bred there, which came to Europe many centuries later.
On the territory of Russia, lemon can be grown in southern regions with a subtropical climate, for example, on the Black Sea coast of the Caucasus.
But even in such a mild climate as the Black Sea, it is often necessary to use greenhouses, since in the winter season quite
severe frosts and large amounts of precipitation in the form of snow are not uncommon.
To increase the frost resistance of lemon, breeders breed new varieties with increased resistance to low temperatures.