Morus

Morus 

(mulberry), a genus of trees of the family Moraceae. The trees are 16–35 m tall. The crown is spherical, broadly ovate, and very dense. The bark is brown and cracked. The bare or pubescent ovate leaves have stipules that shed early; their edges are lobate or crenate. The plants are usually dioecious. The flowers are bisexual and gathered in catkins. The fruit—a succulent compound false drupe—measures 1–5 cm in length and is white, pink, dark violet, or almost black.

There are about 24 species, distributed in eastern and southeastern Asia, in southern Europe, in the southern parts of North America, in the northwestern parts of South America, and in parts of Africa. The USSR has four species, in the southern European portion and in Middle Asia. The mulberry tree is cultivated for its leaves, which are used to feed silkworms, and for its fruit. The fruits are sweet or tart, with a sugar content of at least 10 percent. They are eaten fresh or dried, or they are processed into wine. Mulberry wood is strong, resilient, and heavy; it is used as a building and woodworking material.

In the USSR the white mulberry (M. alba), M. bombycus, and M. multicaulus are raised for silkworm cultivation, and the black mulberry (M. nigra)is cultivated for fruit. In the USSR local forms, for example, Khasak, Kaichi, and Dzhir, are cultivated as forage crops, as are the new highly productive varieties SANIISh–5, SANIISh–6, SANIISh–7, SANIISh–14, SANIISh–15, SANIISh–17, Tadzhikskaia seedless, Irtyshar, Uzbekskaia, Pion-erskaia, Iveriia, Tbilisuri, Ukrainskaia–9, and Ukrainskaia–107. A significant portion of the feed plantings consists of hybrids. For spring feeding of mulberry silkworms the annual branches are cut annually. For summer and fall feedings, the upper third of new shoots is cut. Every four or five years the trees are given a year of rest.

Mulberry trees are drought resistant, relatively undemanding of soils, and salt tolerant. They are not resistant to flooding. Propagation is by seeds, grafts, and layers. The most widespread diseases are bacteriosis, Cylindrosporium disease, mildew, root rot, and curl. The most common insect pests are Apocheima cinerarius, Pseudocaccus comstocki, mole crickets (Gryllotalpa), chafers, wireworms, the mulberry longicorn beetle, and spider mites. (See alsoMULBERRY CULTIVATION.)

REFERENCE

Derev’ia i kustarniki SSSR, vol. 2: Pokrytosemennye, Moscow-Leningrad, 1951.

A. G. KAFIAN