an arboreal plant of the genus Castanea of the family Fagaceae. There are 14 known species, distributed in North America, Japan, China, and the Mediterranean region. In the USSR, one species is found on the Black Sea Shore of the Caucasus and in Transcaucasia. The European, or Spanish, chestnut (Castanea sativa) is cultivated. The chestnut tree is large (height, up to 35 m; diameter, 2 m) and long-lived (500 and more years). It has a large, spreading crown and a strong, deep root system. The flowers, which are gathered into catkins, are small, unisexual or bisexual, and cross-pollinating. The fruits are nuts (length and width, 1.5– cm), with a delicate grayish brown woody pericarp. Three nuts are usually found in each involucre. The tree begins to fruit after 5–10 years. When the tree is 50 years old, it produces at least 70 kg of nuts (up to 1 ton per hectare).
The chestnut is demanding in terms of light, warmth, and moisture. The tree grows best on brown semihumid acid soils. Chestnut trees are cultivated in Italy, Spain, France, and the USA. In the USSR, they are grown in the Caucasus, the Crimea, Transcaucasia, and Moldavia. The nuts are edible in fresh and cooked form. They are used as an ersatz coffee and as an ingredient in candy. The chestnut kernel contains more than 60 percent starch, up to 17 percent sugar, 8– percent nitrogen compounds, and over 2 percent fat. Chestnut wood, which is of very high quality is valued in wood-working industries and is also used in construction. It is resistant to rot. The wood, the bark, and the nutshells, which are rich in tanning and dyeing substances, are used in the production of textile dyes. There are several types of chestnut trees; they differ in size, taste of the nut, and rate of growth. In the USSR, there are several varieties, including the large-fruited and small-fruited types. Foreign varieties include the Lyon and the Neapolitan; both have very large and tasty fruits.
Usually chestnuts are propagated by seeds. However, the best varieties are propagated by grafts and cuttings. The seeds are stratified in the autumn and planted in a nursery in the spring. The seedling stocks are then grafted with a fistula or bud. Chestnut trees are grown on slopes in deep, well moistened, fertile soils. Each seedling is planted in an area measuring 18 m X 18 m or 20 m X 20 m. The spaces between the rows are used for temporary plantings (for example, filbert trees). The crown of the chestnut tree is formed by 8– boughs and by a trunk measuring 70– cm high. The tending of the soil, including its fertilization and irrigation, is very similar to the care of apple orchards. The most dangerous insect pests are the moth and weevil. Chestnut trees are susceptible to several diseases, including root and trunk cancer and core brown rot. Besides the species of the family Fagaceae, there are species of the family Hippocas-tanaceae that are also called chestnuts, for example, the horse chestnut (Aesculus hippocastanum).
V. A. KOLESNIKOV