MORUS ALBA: CHARACTERISTICS, HABITAT, PROPERTIES, VARIETIES, CULTIVATION - BIOLOGY - 2024

Morus alba is a species of deciduous tree with a branched and leafy stem that belongs to the Moraceae family. Known as white mulberry or simply mulberry, it is a natural plant from China that is widely distributed throughout Asia, Southern Europe and America.

It is a tree with a smooth and grayish bark when young, but rough and brown when aging, it has numerous branches and a wide crown. Alternate leaves, petiolate, oval, toothed or lobed, dark green in color, the unisexual flowers are grouped in very dense spikes, the fruit is an edible fruit of light or dark color.

Morus alba. Source: Alborzagros / CC BY-SA (https://creativecommons.org/licenses/by-sa/4.0)

Mulberry is a wild species that is cultivated as an ornamental plant due to its dense foliage and resistance to adverse conditions. Its leaves are used as fodder for livestock or as food for the reproduction and rearing of the silkworm.

In the cosmetic industry, the leaves and roots are raw material for obtaining extracts that are used to make skin softeners or conditioners. In herbal medicine, the knowledge of its roots has anti-inflammatory properties and the habitual consumption of the fruits increases the body's defenses due to its antioxidant properties.

General characteristics

Appearance

Deciduous tree 6-18 m tall, thin, smooth and greyish bark in young plants, thick, cracked and brownish in adult plants. Extensive branching, thin erect or pendulous branches, dense and rounded crown. It is considered a very long-lived species, some specimens live more than 100 years.

Leaves

Simple, alternate, petiolate and deciduous leaves, measuring between 10-25 cm long and 5-15 cm wide. They are characterized by the variability of shapes, from heart-shaped, oval or rounded, some with two or more lobes, serrated and hairy margins.

The blade can be obliquely chordate and the apex acuminate, glabrous and shiny on the upper surface, pubescent or opaque on the underside. Its coloration varies from bright-green to pale-green or yellow, with obvious hairy veins, as well as sharp marginal teeth.

flowers

The unisexual flowers are grouped into inconspicuous cream-green catkins. The female or male flowers are located on the same foot or on separate feet, so they are monoecious or dioecious. Flowering occurs in mid-April and fruiting 30-40 days later.

Inflorescences of Morus alba. Source: Jeekc / CC BY-SA (https://creativecommons.org/licenses/by-sa/4.0)

Fruit

The fruit is a cylindrical drupe, sometimes lanceolate, with a white, pink, red or black-purple color that is grouped into infrutescences. It is considered a compound fruit known as sorosis, similar to the blackberry, provided with a long stem and when ripe it is pasty in consistency.

Chemical composition

The fruits of the mulberry tree are rich in sugars, proteins and vitamins, especially ascorbic acid or vitamin C, as well as calcium, copper and potassium. In addition, it contains anthocyanins, pectins, quercetin, resveratrol, malic acid and tartaric acid, and certain phenolic compounds, such as gallic acid.

In the leaves, the presence of betulinic, chlorogenic, gallic and protocatechic organic acids is common, as well as r-hydrobenzoic, coumaric, ferulic and vanillic acids. Oxyresveratrol and mulberroside A, stilbenoids used in cosmetology, are also found in the roots and leaves.

Taxonomy

- Kingdom: Plantae

- Phylum: Magnoliophyta

- Class: Magnoliopsida

- Order: Rosales

- Family: Moraceae

- Tribe: Moreae

- Genus: Morus

- Species: Morus alba L.

Etymology

- Morus: the name of the genus comes from the Latin «morus, -i» and the Greek «μορέα» used since ancient times to designate the name of the mulberry tree.

- alba: the specific adjective derives from the Latin «albus, -a, -um» which means white, referring to the color of its flowers, bark and fruits.

Synonymy

- Morus Acidosa Griff.

- Morus australis Poir.

- M. bombycis Koidz.

- M. cavaleriei H. Lév.

- Morus chinensis Lodd. ex Loudon

- Morus formosensis Hotta

- M. hastifolia FT Wang & T. Tang ex ZY Cao

- M. intermedia Perr.

- Morus inusitata H. Lév.

- Morus latifolia Poir.

- M. longistylus Diels

- M. multicaulis Perr.

- Morus nigriformis (Bureau) Koidz.

- Morus tatarica L.

Fruits of Morus alba. Source: pixabay.com

Habitat and distribution

The Morus alba species is native to Southwest Asia, specifically North China, Correa and Manchuria. Since ancient times it has been naturalized in different temperate regions around the world because it is the ideal means to raise the silkworm.

Mulberry trees adapt to different types of soils, although they prefer deep, fertile and low-acid soils. They grow in full sun exposure or half shade, however, they need a large space because they reach a considerable size.

It is a rustic species that tolerates environmental pollution, severe pruning and large variations in temperature, be it winter cold or summer heat. Provided it receives good lighting and has frequent availability of water.

In addition, it is very resistant to strong winds and tolerates saline soils. Indeed, it is an ideal plant to grow in lands near the coasts or coastlines.

In the wild it is located in meadows, gallery forests or mountainous areas, on trails and roads, over an altitude range of 0-900 meters above sea level. It is easily propagated through seeds dispersed by birds or small mammals, commercially by cuttings or grafts, being a fast growing crop.

At present, it has been naturalized in many regions of Asia, Europe and America, being cultivated in the Mediterranean basin for many years. In the Iberian Peninsula it has been cultivated as an ornamental plant, being of great economic importance in the regions of Murcia and Granada for the breeding of the silkworm

Properties

Types of leaves of Morus alba. Source: Jaknouse / CC BY (https://creativecommons.org/licenses/by/3.0)

Ornamental

In a tree that is cultivated as an ornamental in squares, parks and gardens due to its dense foliage and wide crown. During the summer months the mulberry trees provide a closed shading around them. As a hedge it is used for the separation of boundaries and aligned in walks, streets or roads.

Medicinal

The root, bark, leaves and fruits of the mulberry have been used since ancient times for their therapeutic properties. Mulberry contains various secondary metabolites that provide it with an antipyretic, diuretic, deworming and emollient effect.

The intake of infusions prepared with the root is effective to calm coughs, relieve symptoms of bronchitis and as an expectorant against asthma. The fruits are appreciated for their tonic effect in case of hypertension, insomnia and certain depressive symptoms, such as neurasthenia. The leaves have antipyretic action.

Leaves and inflorescences of Morus alba. Source: pixabay.com

Industrial

The roots of Morus alba have a high content of tannins and pigments that are used to dye various types of fabrics. In addition, the fibers of its bark are used to make high-quality, firm ropes.

The wood, hard, permeable and with a yellowish hue is used for the manufacture of slats, beams, posts or rustic furniture. It is also perfect for making sporting goods such as tennis, table tennis or badminton rackets, hockey blades, cricket bats, even agricultural implements.

Nutritional

The fruits are used to make juices, compotes and jams. In the same way, they are used as raw material in confectionery, to decorate cakes and the elaboration of artisan liquors.

Forage

The Morus alba species is considered the only food source for the Bombyx mori L. species, one of the main silk-producing worms in the world. In fact, mulberry is a plant of great economic importance for countries that depend on the production of silk.

Silkworm rearing consists of keeping the eggs in a closed environment with a constant temperature of 18ºC. The incubation of the eggs is achieved by gradually increasing the temperature to 25 ºC.

Once the worms have developed, they are fed hand-chopped mulberry leaves until they are fattened and enter the cocoon stage. From this stage, the silk that forms around the cocoon is extracted by boiling the eggs, producing filaments up to 900 m long.

In some regions, the young leaves are used as fodder for feeding cattle.

V arieties

Raft

An erect, highly branched and vigorous variety, the foliation occurs during the month of March. Glossy pale green lanceolate leaves, irregular and serrated blade, medium-sized, rounded and black fruits, sweet taste. Abundant production.

Christian

It is considered the most widely cultivated variety in the southeast of the Iberian Peninsula for silkworm breeding. It is a highly branched tree of medium vigor, lanceolate leaves, small black fruits, late foliation between April and May.

Filipino or multicaule

Early variety that is usually affected by frost. It is a tree with an open and widely branched bearing, large leaves with a rough and rough texture, black fruits, medium size and sour taste, not very productive.

Pendula

Variety grown only as an ornamental plant, it is a vigorous tree with pendulous branches, the foliation occurs between April and May. Medium-sized lanceolate leaves, twisted, toothed margins, abundant, medium-sized, black fruits, very sweet.

Valencian

Two sub-varieties are common, one early and the other late, with the late being the one indicated for the rearing of the silkworm during the fall. It is a slightly branched tree, large, cordate and bright green leaves, curled in the early variety, medium-sized white fruits.

Bark of Morus alba. Source: Andre Abrahami / CC BY-SA (https://creativecommons.org/licenses/by-sa/2.5)

Widow

Variety of globose, leafy, but little branched habit, the foliation appears at the end of March. Small, lanceolate and light green leaves, irregularly toothed margins, abundant white fruits, medium size, rounded and very sweet.

Culture

Spread

Mulberry is propagated sexually by means of seeds or vegetatively through cuttings or grafts. Commercially, propagation by seed is not very effective, due to the low germination percentage of its seeds, which is around 50%.

Propagation by seed is used at an experimental level when it is desired to obtain new varieties according to selective crosses to improve their phenotypic characteristics. Germination takes place in seedlings or germination beds with a substrate of fine sand and organic matter, maintaining continuous humidity until the seedlings emerge.

For multiplication by means of cuttings, a piece of young branch 10-15 cm long and 4-5 leaf buds is required. The cuttings are introduced into a fertile substrate, after application of rooting phytohormones, ensuring constant humidity and temperature until the roots sprout.

Requirements

- Mulberry adapts to a wide range of climatic conditions, be it winter frosts or hot environments during summer. Its growth range ranges from 15ºC to 40ºC.

- It is a rustic plant that grows on various types of soils, whether low fertility or high content of organic matter. However, the optimal soils are those with a sandy-loam or clay-loam texture, slightly acidic pH (6.5-7), deep and permeable.

Illustration of Morus alba. Source: Francisco Manuel Blanco (OSA) / Public domain

Care

- The Morus alba species is a very resistant tree, fast growing and low maintenance.

- It develops in full sun exposure, supports the strong coastal winds and the sea breeze.

- It tolerates anthropic conditions, hence it develops effectively in environments with high levels of pollution within cities.

- It adapts to different types of soils, as long as it has a certain level of fertility, not very acidic pH and frequent humidity.

- The best development and productivity of mulberry trees is obtained in deep soils, with a high content of organic matter and well drained.

- Tolerates water deficit, as long as it does not last for a long time.

- Its growth temperature range varies from occasional frosts during winter to very high temperatures during summer.

- It requires maintenance pruning to avoid the formation of very long branches and promote the proliferation of buds and flower buds.

Diseases and pests

Unlike other species of the same genus, Morus alba does not present significant problems related to pests or diseases. The presence of aphids on the young shoots is common, promoting the appearance of the fungus called bold that affects the photosynthetic process of the leaves. On the other hand, in old plants the appearance of leaf spots produced by Cescospora moricola is frequent.

References

1. Benavides, JE (1995). Management and use of mulberry (Morus alba) as forage. Agroforestry in the Americas, 2 (7), 27-30.
2. Castro, A., & Orozco, E. (2011). Mulberry cultivation (Morus spp.) And its use in animal feed. INTA Publications. San José of Costa Rica.
3. Mulberry cultivation (2020) Agromática. Recovered in: agromatica.es
4. González Marín, F. (2000) La Morera. Region of Murcia Digital. Recovered at: regmurcia.com
5. Llopis Martínez, C. (2013) Morus alba L. Medicinal Plants: Phytotherapy, Natural Health and Herbalism. Recovered in: Plantas-medicinales.es
6. Morus alba L. (2015) Catalog of Life: 2015 Annual Checklist. Recovered at: catalogueoflife.org
7. Morus alba (2018) Tree App. Recovered at: arbolapp.es
8. Morus alba. (2020). Wikipedia, The Free Encyclopedia. Recovered at: es.wikipedia.org
9. Morus alba (2020) The Tree © Species of Trees and Plants. Recovered at: elarbol.org