Зизифус мавританский: описание и распространение

Species of plant

Ziziphus mauritiana, also known as Indian jujube,

Ziziphus mauritiana is a spiny, evergreen shrub or small tree up to 15 m high, with trunk 40 cm or more in diameter; spreading crown; stipular spines and many drooping branches. The fruit is of variable shape and size. It can be oval, obovate, oblong or round, and can be 1 2.5 in (2.5 6.25 cm) long, depending on the variety. The flesh is white and crisp. When slightly underipe, this fruit is a bit juicy and has a pleasant aroma. The fruit's skin is smooth, glossy, thin but tight. The species is believed to have originated in Indo Malaysian region of South and South East Asia. It is now widely naturalised throughout the Old World tropics from Southern Africa through the Middle East to the Indian subcontinent and China, Indomalaya, and into Australasia and the Pacific Islands. While the Rhamnaceae family are considered nitrogen fixing trees, Ziziphus mauritiana can form dense stands and become invasive in some areas, including Fiji and Australia, and has become a serious environmental weed in Northern Australia. It is a fast growing tree with a medium lifespan, that can quickly reach up to 10–40 ft (3 to 12 m) tall.

Ziziphus mauritiana is a medium sized tree that grows vigorously and has a rapidly developing taproot, a necessary adaptation to drought conditions. The species varies widely in height, from a bushy shrub 1.5 to 2 m tall, to a tree 10 to 12 m tall with a trunk diameter of about 30 cm. Z. mauritiana may be erect or wide spreading, with gracefully drooping thorny branches, zigzag branchlets, thornless or set with short, sharp straight or hooked spines. The leaves are of different size with ovate or elliptic shape with rounded apex, with 3 depressed longitudinal veins at the base. The size (length x width) of the leaves from the tender to senescent states ranges, ~4.7 cm x 2.5 cm 9.6 cm x 7.3 cm. The upper side (adaxial) of the leaves displays a deep green hue with an oily surface, while the lower side (abaxial) covered with micro fibers surface. The fiber diameter of matted abaxial leaf surface ranges, ~5.6 to 7.1 micrometers. Recently, M. C. Dubey et. al., reported that the micro fibrous surface morphology of the abaxial leaf surface exabits superhydrophobicity and contributes to the "cool roof" characteristics of the leaves. The flowers are tiny, yellow, 5 petalled and are usually in twos and threes in the leaf axils. Flowers are white or greenish white and the fruits are orange to brown, 2–3 cm long, with edible white pulp surrounding a 2 locular pyrene. The tree has a high tolerance to both water logging and drought and can grow where annual rainfall ranges from 125 to 2,225 mm, but is more widespread in areas with an annual rainfall of 300 to 500 mm. In China and India, wild trees are found up to an elevation of 5,400 ft (1,650 m). In India, the minimum shade temperature for survival is 7–13° and the maximum temperature is 50 °C. Studies report that this species flourishes in alkaline soils with a pH as high as 9.2. However, deep sandy loam to loamy soils with neutral or slightly alkaline pH are considered optimum for growth. In India, the tree grows best on sandy loam, neutral or slightly alkaline.

Some cultivars attain anthesis early in the morning, others do so later in the day. The flowers are protandrous. Hence, fruit set depends on cross pollination by insects attracted by the fragrance and nectar. Pollen of the Indian jujube is thick and heavy. It is not airborne but is transferred from flower to flower by honeybees. Seedling trees bear 5,000 to 10,000 small fruits per year in India. Superior grafted trees may yield as many as 30,000 fruits. The best cultivar in India, with fruits normally averaging 30 to the lb (66 to the kg), yields 175 lbs (77 kg) annually. Special cultural treatment increases both fruit size and yield.

The major production regions for Indian jujube are the arid and semi arid regions of India. From 1984 to 1995 with improved cultivars the production was 0.9 million tonnes on a land of 88,000 ha. The crop is also grown in Pakistan, Bangladesh and parts of Africa. Trees in northern India yield 80 to 200 kg of fresh fruit/tree/year when the trees are in their prime bearing age of 10–20 years. In India and Queensland, the flowers are rated as a minor source of nectar for honeybees. The honey is light and of fair flavor. Ber timber is hard, strong, fine grained, fine textured, tough, durable, and reddish in colour. It has been used to line wells, to make legs for bedsteads, boat ribs, agricultural implements, tool handles, and other lathe turned items. The branches are used as framework in house construction and the wood makes good charcoal with a heat content of almost 4,900 kcal per kg. In addition, this species is used as firewood in many areas. In tropical Africa, the flexible branches are wrapped as retaining bands around conical thatched roofs of huts, and are twined together to form thorny corral walls to retain livestock. The fruits are applied on cuts and ulcers; are employed in pulmonary ailments and fevers; and, mixed with salt and chili peppers, are given in indigestion and biliousness. The dried ripe fruit is a mild laxative. The seeds are sedative and are taken, sometimes with buttermilk, to halt nausea, vomiting, and abdominal pains in pregnancy. They check diarrhea, and are poulticed on wounds. Mixed with oil, they are rubbed on rheumatic areas. The leaves are applied as poultices and are helpful in liver troubles, asthma and fever and, together with catechu, are administered when an astringent is needed, as on wounds. The bitter, astringent bark decoction is taken to halt diarrhea and dysentery and relieve gingivitis. The bark paste is applied on sores. The root is purgative. A root decoction is given as a febrifuge, taenicide and emmenagogue, and the powdered root is dusted on wounds. Juice of the root bark is said to alleviate gout and rheumatism. Strong doses of the bark or root may be toxic. An infusion of the flowers serves as an eye lotion. The fatty acid methyl ester of Z. mauritiana seed oil meets all of the major biodiesel requirements in the USA (ASTM D 6751 02, ASTM PS 121 99), Germany (DIN V 51606) and European Union (EN 14214). The average oil yield is 4.95 kg oil/tree or 1371 kg oil/hectare, and arid or semi arid regions may be utilised due to its drought resistance.

The greatest enemies of the jujube are fruit flies. Some cultivars are much more susceptible than others, the flies preferring the largest, sweetest fruits. 100% of those may be attacked, while on a neighbouring tree bearing a smaller, less sweet type, only 2% of the crop may be damaged. The larvae pupate in the soil and it has been found that treatment of the ground beneath the tree helps reduce the problem. Control is possible with regular and effective spraying of insecticide. A leaf eating caterpillar and the green slug caterpillar attack the foliage. Mites form scale like galls on twigs, retarding growth and reducing the fruit crop. Lesser pests include the small caterpillar of Meridarchis scyrodes, that bores into the fruit. The tree is subject to shrouding by a parasitic vine. Powdery mildew causes defoliation and fruit drop, but it can be adequately controlled. Lesser diseases are sooty mould, brown rot and leaf spot. Leafspot results from infestation by Cercospora spp. and Isariopsis indica var. zizyphi. In 1973, a witches' broom disease caused by a mycoplasma like organism was found in jujube plants near Poona University. It proved to be transmitted by grafting or budding diseased scions onto healthy Z. mauritiana seedlings. Leaf rust, caused by Phakopsora zizyphivulgaris, ranges from mild to severe on all commercial cultivars in the Punjab. In storage, the fruits may be spotted by fungi. Fruit rots are caused by Fusarium spp., Nigrospora oryzae, Epicoccum nigrum, and Glomerella cingulata.