HELPFUL OF NEEM TREES IN AQUACULTURE

 A. Overview 

 

The neem tree is also known as the winter melon, the melancholy, the ta tree (distinguished from the Indian oval), the house tree (distinguished from the forest oval), practicing, practicing hard. The tree is native to Asia, but widely distributed almost all over the world, with many different English names such as, Persian lilac, Paradise tree, Pride of India, White cedar... It is a species of the family. Xoan - Meliaceae, with current scientific name is Melia azedarach and synonyms are M. sempervirens, M. australis, M. japonica.

Neem tree

The neem tree is a small tree with seasonal deciduous trees, the tree is usually 7-20 m high, in some places (Northern Australia) the tree is more than 40 m tall. The plant bears compound leaves, two to three times odd, leaflets serrate; light green young leaves. Flowers are small, white with purple heart, growing in clusters of large canopy, blooming in mid-spring, many trees are full of energy, in the sexual season, the flowers are in full bloom. Fruit oval 1 x 1.5 cm, green skin when young, yellow then wrinkled and withered when ripe, hanging for days on branches, when falling or being dispersed by birds, regenerates into trees child easily.

B.   B. Function of neem tree

The leaves are used as a natural insecticide to preserve certain foods. Because of its toxicity, the leaves of the neem tree can't be eaten. In the past, the resin and essential oils distilled from the leaves and stems of the plant, when diluted, were used to relax muscles.

The flowers are unattractive to butterflies and bees. Round and hard rhododendrons were commonly used to make rosaries and other similar products before the plastic industry prevailed and supplanted the rhododendron material.

The bark of the stem, the bark of the big branches, the bark of the roots, and the leaves can all be used as medicine. When taking the bark as medicine, it is advisable to choose trees that have reached the age of logging (trees are 6-7 years old) shaved off the outer bark, and dried or used. Usually, root bark is better used than stem bark.

C. Chemical composition of neem tree

In the peel there are vitamins, oxalate salts, margosin substances; There are also kulactone, kulolactone, kulinone, methyl kulonate, toosendanin.

Chemical studies show that the family contains many triterpenoids tirucallan, dramaran, oleanane, multiflora and some alkaloids. In addition, this family contains many limonoids. In the world, there have been many studies on extracting chemical substances applied in the prevention and treatment of diseases. Studies have shown that extracts from various parts of the neem tree have the ability to fight the growth of bacteria and eliminate the fungus Lemna minor.

Oval stem bark and root bark (like Melia) contain an alkaloid (formula C9H8O4) with bitter taste that kills worms. In addition, the bark and root bark contain 70% tannin. The fruit contains an alkaloid called Azaridin and an oily substance (accounting for 60%), the oil has sulfur and the smell of garlic. The leaves contain an alkaloid called paraisin, a little rutin (0.5% dry matter).

D. Poisonousness of neem tree

All parts of the neem tree are toxic to humans if ingested. Toxic factors are neurotoxic substances containing tetranortriterpenes and unspecified resins; the highest concentration contained in the fruit. Some birds are able to eat the neem tree so that its seeds are dispersed when they are dropped, but just 15 grams of the seeds are lethal to a 22-kilogram pig. The first symptoms of poisoning appear only a few hours after ingestion. These symptoms include loss of taste, vomiting, constipation or diarrhea, bloody stools, stomach damage, pulmonary congestion, heart failure... Death can occur after about 24 hours

Helpful of neem trees in aquaculture

In aquaculture, neem leaves have been used for many years, mostly used to disinfect anchors and some other external parasites on fish. After being harvested fresh, the leaves are bundled into bundles and immersed in the pond water (dipping depth from 20-40 cm), when soaking the leaves, the purpose is to dissolve the alkaloid, which has a very strong bactericidal effect on the anchor. In 7-10 days, when the leaves come off, we remove the petioles. When using neem leaves to kill external parasites on fish, it is important to note the lack of air in the pond in the early morning. In addition, at times of unfavorable weather, the low temperature of Xoan leaves also limits parasitic agents in fish syndrome with missed ulcers.

 

Souce by Vincors