lemon
lemon
lemon
[′lem·ən]Lemon
(Citrus limonio), a perennial evergreen subtropical plant of the genus Citrus of the family Rutaceae and the subfamily Aurantioideae. It measures from 3 to 7 m high. The branches are usually spiny. The leaves are leathery, light green, and either elongate-lanceolate or elongate-ovate. Their tips are constricted and denticulate. The leaves have translucent glandules and a specific fragrance. The flowers, which are bisexual, white, and aromatic, are on short pedicels, in small racemes, solitary, or paired. The fruit has many sections and is ellipsoid or, more rarely, nearly round. It measures 6–7 cm in length and 5–6 cm in diameter and weighs up to 120 g. The skin of the fruit is 2–5 mm thick, lemon-yellow, and smooth or with oily glandules; it is bitter and has a characteristic aroma. The pulp is a greenish pale-yellow, fine grained, juicy, and very sour. The seeds are light in color and smooth; 20 and more are found in each fruit.
In the subtropics of the USSR there are three picking seasons —spring, summer, and fall. Between pickings the plant is relatively dormant. Lemon trees are thermophilic and photophilic. Spring growth begins when the average daily temperature is above 10°C. The period of growth and development lasts 200–220 days, and the optimum temperature for growth and flowering is 17°-18°C. Without sufficient light, large leaves form, and the trees grow and bear fruit poorly. The lemon is the most hygrophilous citrus fruit.
Native to Southeast Asia, the lemon has not been found in wild form. It is cultivated in the subtropics of the Mediterranean region, the United States, Mexico, and Argentina. It has been raised in the USSR for more than 200 years. The lemon grows best in open areas, such as the Black Sea shore of the Caucasus, the Azerbaijan SSR, and Middle Asia, where it is grown in trenches. In many places lemons are also raised indoors.
The fruits, or lemons, of the lemon tree have 3.5–8.1 percent acids (chiefly citric) and 1.9–3.0 percent sugar. For every 100 g there are 45–140 mg of vitamin C; the fruit also contains vitamins P and B, pectin substances, iron, phosphorus, calcium, sodium, potassium, and magnesium. Lemons are eaten fresh or used for producing juice and citric acid. Their peel contains lemon oil, which has a distinctive fragrance.
In the USSR several varieties are grown, including Novogruzinskii, Limon Kuznera, and Bez Koliuchek (without spines). Lemons are propagated from grafts and cuttings. Grafted lemon trees begin fruiting in the third or fourth year. A tree yields 150–300 fruits annually. In open areas lemons are grown as creeping or semidwarf trees. In the spring the plants are planted in warm areas protected from cold winds, on loose soil that is rich in humus and has good water and air drainage. Creeping varieties are planted in rows spaced 2.5–4 m apart; semidwarf plantings are spaced 2.5–3 apart, with 4 m between rows. Under each tree 10–50 kg of manure, as well as 20–300 g of nitrogen, 80–350 g of phosphorus, and 50–120 g of potassium fertilizers, are applied (quantity depending on the soil and the age of the tree). During the period of growth and development, unwanted shoots are removed and shoots that grow too vigorously are pruned.
A. D. ALEKSANDROV