Prunus
prunus
(ˈpruːnəs)Noun | 1. | Prunus - a genus of shrubs and trees of the family Rosaceae that is widely distributed in temperate regions |
单词 | prunus | |||
释义 | Prunusprunus(ˈpruːnəs)
PrunusPrunusa genus of stone-fruit plants of the family Rosaceae. The trees or shrubs are 3–12 m tall. Their leaves, which are simple and alternate, may be round, elliptical, or lanceolate. The white or pink flowers are solitary or in inflorescences of two to five. The fruit is a fleshy, one-seeded drupe; its shape may be oval, round, or ovate. The drupe weighs 6–100 g and is yellow, green, red, purple, or bluish black with a bluish waxy bloom. There are more than 30 known species, distributed in Europe, Asia, and North America. Seven species are found in the USSR. The common, or European, plum (P. domestica) is the most well-known species. The plum’s origin has not been precisely established, but it is thought that the plum resulted from the natural crossing of the blackthorn (P. spinosa) and cherry plum (P. cerasifera) and subsequent selection in cultivation. The common plum is believed to be native to the Caucasus, Asia Minor, and northern Iran. A tree reaching a height of 12 m, it has pubescent or naked shoots. The leaves vary in form and color, but all flowers are white. The fruits vary in shape, color, size, taste, degree of pubescence, and maturation period. The fruits contain 9–20 percent sugar and 0.4–1.4 percent organic acids (malic acid, citric acid); they also contain nitrogenous substances, vitamin B1, vitamin B2, vitamin C, vitamin K, vitamin PP, carotene, and minerals. They are used raw and in the form of prunes, juice, preserves, stewed fruit, and liqueurs. The common plum grows in Western Europe, northern and southern Africa, northwestern India, eastern Asia, and North America. In the USSR it is cultivated primarily in Moldavia, the Ukraine, the Caucasus, Middle Asia, and southern Byelorussia. There are approximately 2,000 known varieties, of which several dozen are cultivated. The varieties are divided into pomological groups: Vengerka, Reine Claudes (greengages), Mirabelles, and Yellow Eggs. Common varieties cultivated in the southern regions of the USSR include the Anna Shpet, green Reine Claude, Vengerka Ital’ianskaia, Altana Reine Claude, Vengerka Domashniaia, Tules Grass, and Persikovaia. In the central region of the European USSR common varieties include the Skorospelka Krasnaya, Kolkhoznyi Reine Claude, and Volzhskaia Krasavitsa. Plums are raised on fertile soils, which have been deeply tilled and fertilized. The planting stock consists of grafted saplings (one- and two-year-olds) and shoots. In the central regions of the European USSR the best stocks are local cultivated plums, bullace, and blackthorn; in the south the cherry plum is the most popular stock. In southern regions planting is done in autumn or spring, and in central and northern regions planting is done only in spring. Crop care involves loosening the soil, applying fertilizers, weeding, pruning the crowns, and controlling pests and diseases. In regions of insufficient moisture it is necessary to water the trees. Depending on the variety, the natural conditions, and the agricultural technology, the tree will bear fruit in the fourth to sixth year and will live 15 to 60 years. Each tree may yield up to 100 kg of fruit under favorable conditions, but the average yield is 15–30 kg. Fruits to be transported are hand- or machine-picked three to six days before they are fully ripe; many types of processing require the fully ripe fruit. In addition to the common plum, several other species are cultivated in the USSR. P. ussuriensis, a shrublike tree reaching 8 m tall, grows in the Far East, Siberia, and Kazakhstan. Its small aromatic fruits are tart, usually yellow, and cold resistant. The Japanese plum (P. salicina), a tree measuring 6–10 m tall and having shiny, bare shoots, grows in the Far East. Its average- or large-sized fruits are red, yellow, or violet. The Canada plum (P. nigra), one of the hardiest plum species, is cultivated in Siberia. A tree reaching 9 m tall, it has small round or elongated red-orange fruits. Japanese and Canada plums include many winter-hardy varieties. Insect pests of plum trees include Hyalopterus pruni, the plum moth, Eurytoma samsonovi, Haplocampa flava, Trachelus tabidus, the snout beetle, scale insects, and the pierid butterfly. Diseases include gray mold, leaf spot, cercosporiosis, rust, gumming, and red rot. REFERENCESKostina, K. F. Kul’tura slivy. Simferopol’, 1951.Anzin, B. N., Kh. K. Enikeev, and M. I. Rozhkov. Sliva. Moscow, 1956. Enikeev, Kh. K. Biologicheskie osobennosti slivy i vyvedenie novykh sortov. Moscow, 1960. Kursakov, G. A., L. E. Kursakova, and I. I. Vanin. Vishnia isliva. Moscow, 1966. G. A. KURSAKOV PrunusPrunus(prū'nŭs),Prunus
Synonyms for Prunus
|
|||
随便看 |
英语词典包含2567994条英英释义在线翻译词条,基本涵盖了全部常用单词的英英翻译及用法,是英语学习的有利工具。