where is azolla found

Full Answer

What is Azolla?

Azolla may also be referred to as red azolla, feathered mosquito fern, water velvet or African azolla and has a native range extending from Africa to India, Southeast Asia and Australia. Basic requirements Azolla must be grown in fresh water or wet mud in order for the plant to thrive as the plants will die within a few hours if allowed to dry out.

Is Azolla native to Tasmania?

It is a common native aquatic plant in Tasmania. It is common behind farm dams and other still waterbodies. The plants are small (usually only a few cm across) and float, but can be abundant and form large mats. The plants are typically red, and have small, water repellent leaves. Azolla reproduces sexually, and asexually (by splitting).

Where to find Azolla in a pond?

Azolla can vary in color from green to red and are generally found in quiet ponds protected from wind action. Azolla can be aggressive invaders in quiet ponds and are often found mixed in with duckweed or watermeal.

Where did Azolla filiculoides come from?

Native to the Americas, Azolla filiculoides was introduced to the UK in the 19th century and became naturalized, going on to become widespread on slow moving and stationary water bodies, frequently infesting valuable or threatened habitats.

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Where can we find Azolla?

Azolla occurs naturally in freshwater ditches, ponds, lakes and sluggish rivers of warm-temperate and tropical regions.

Where does Azolla grow?

Azolla can survive within a water pH range of 3.5 to 10, but optimum growth occurs in the pH range of 4.5 to 7 and temperature range of 18°C to 26°C. Under optimum conditions, azolla's growth spreads across the dam surface until it covers the surface of the water in a dense cover.

Can humans eat Azolla?

Azolla is widely used as a livestock feed in India and the Far East, but its potential as a food for people is less well known. This is now changing and some of the impetus has come from studies into diets that could be used for space stations, space travel, and habitation on the Moon and Mars.

Which Azolla is used in India?

Azolla is a free-floating aquatic fern. There are six species of Azolla – Azolla Carolina, Azolla nilotica, Azolla filiculoids, Azolla Mexicana, Azolla microphylla and Azolla pinnata. The Azolla Pinnata is a common species in India....No.CompositionComposition on the basis of dry wt. (%)14.Chlorophyll0.34 – 0.513 more rows

Do cows eat Azolla?

Livestock can easily digest azolla due to its high protein content and low lignin content. Fresh azolla can be mixed with commercial feed in the ratio 1:1 or given directly to livestock. It was found that the milk production in cattle increased by 10-12% when they were fed with azolla.

How do you make Azolla at home?

A mixture made of cow dung, mineral mixture, soil and water should be added once in seven days. After every 60 days, soil is removed from the bed and another 15 kg of fresh fertile soil is added into the bed to avoid nitrogen build up and also provide nutrient to the azolla.

Why does Azolla turn red?

Azolla is initially green, like duckweed, but soon turns a red or brown color. This coloration is caused by Azolla's association with a nitrogen-fixing cyanobactrium-Anabeana azollae. In this symbiotic relationship, the bacterium gets a safe home while Azolla is provided nitrogen.

Why is Azolla called mosquito fern?

Azolla are weeds in many parts of the world, entirely covering some bodies of water. The myth that no mosquito can penetrate the coating of fern to lay its eggs in the water gives the plant its common name "mosquito fern", and may deter the survival of some of the larvae.

Who discovered Azolla?

The use of azolla in rice production use dates back at least a thousand years in Vietnam. Some legends say that its cultivation was introduced by the Buddhist Monk Khong Mirh Khong in the eleventh century (Doa & Tran, 1979; Moore, 1969).

How much is Azolla for cows?

Production of azolla for livestock feeding An area of 4-4.5 m² and 10-15 cm deep can produce about 2 kg/d of fresh azolla, enough to supplement 2 dairy cows. A plastic sheet should be spread in the pond and properly secured.

Is Azolla good for chicken?

Poultry and in particular ducks and chickens can be raised on a diet including fresh azolla. It has long been recognized as a feed for wildfowl in the USA and for domesticated ducks in China and it has been used as a feed to domestic fowl in Vietnam (Dao & Tran, 1966).

Is Azolla good for fish?

The high level of crude protein of Azolla and higher lysine concentration indicated that Azolla plants may be a good source of fish feed. A significantly higher content of dehydro-ascorbic acid (1,909 mg kg-1 dry weight) than that of L-ascorbic acid (10 mg kg-1 dry weight) in Azolla grown for 3 d was observed.

Where does Azolla live?

Azolla may also be referred to as red azolla, feathered mosquito fern, water velvet or African azolla and has a native range extending from Africa to India, Southeast Asia and Australia. Azolla pinnata. Azolla fronds. Feathered mosquito-fern (Azolla pinnata) Azolla (macro) Azolla. Azolla filiculoides.

What is an azolla?

Azolla, Azolla pinnata, is an aquatic fern belonging to the plant family Azollacea which is grown primarily as a fodder for livestock. Azolla is a small branching plant with a main stem and pinnate side branches.

How to grow Azolla?

Basic requirements Azolla must be grown in fresh water or wet mud in order for the plant to thrive as the plants will die within a few hours if allowed to dry out. Azolla plants can be cultivated in ponds or purpose-built pits and will spread rapidly. If grown in water, there should be little to no current as strong water currents can damage the fronds of the plants. Azolla will grow best in standing water which is between 5 and 12 cm (2.0-4.7 in) deep with a pH between 4 and 7. The roots of the plant should not be able to come into contact with soil at the bottom of the pond or pool as this can cause nutrient deficiencies. Plants will grow optimally at temperatures between 20 and 28°C (68-82.4°F) in partial shade or full sunlight. Heavily shaded areas should be avoided. Propagation Azolla is initially grown by inoculating a prebuilt pit or pond with seed. The azolla will quickly colonize the water and become self propagating. Some of the harvest should be held back to allow the plant to recolonize. Plant matter should be harvested every day to every other day to prevent the pond becoming overcrowded.

How deep does Azolla grow?

Azolla will grow best in standing water which is between 5 and 12 cm (2.0-4.7 in) deep with a pH between 4 and 7. The roots of the plant should not be able to come into contact with soil at the bottom of the pond or pool as this can cause nutrient deficiencies.

How to propagate azolla?

Propagation Azolla is initially grown by inoculating a prebuilt pit or pond with seed. The azolla will quickly colonize the water and become self propagating. Some of the harvest should be held back to allow the plant to recolonize.

What is the genus Azolla?

Definition of the genus Azolla. The genus Azolla is defined as a heterosporous leptosporangiate fern from aquatic and semi-aquatic habitats. It is assigned to the monogeneric Family Azollaceae.

What is the classification of azolla?

Classification of Azolla. “It is a small aquatic plant which appears to float on the water surface in the manner of Lenticules (Lemna) with whom it seems to have a great relation and which nevertheless looks like a small fern.” (translation from the French) Lamarck’s observation of azolla’s habitat must have been based on Commerson’s own ...

Why are azolla hybrids used?

Azolla hybrids have been developed to improve the plant’s temperature tolerance and biomass production. For example, hybridization between A. microphylla and A. filiculoides improves annual biomass production, as illustrated by a study by Van Cat et al. (1989).

How many species are there in Azolla?

According to Francisco Carrapiço (personal communication to J. Bujak), the genus Azolla has six species and three subspecies: “The problem related to the modern Azolla species is still an open question, but based on the classification proposed by Saunders & Fowler (1993) we can consider the following species and subspecies:

Which country has the largest germplasm collection of azolla?

The Philippines ’ International Rice Research Institute (IRRI) has the world’s largest germplasm collection of azolla with more than 500 hybrids. The IRRI is a Foundation Associate and has kindly agreed to make it available to the Azolla Foundation for research projects.

What is the meaning of the word "azo"?

Traditionally, the name is referred to a conjugation of two Greek words, azo (to dry) and allyo (to kill), because the fern is killed by drought, but Carrapiço (2010) has suggested that the name was adopted from a word used by the local population in Argentina or Chile where Commerson collected his specimens of azolla.

Description

Azolla is a small free-floating fern approximately 1 to 3/8 inches wide. Leaves of the mosquito fern overlap, giving a quilted look to the surface and hiding the stem. A single root protrudes from each stem. Azolla can vary in color from green to red and are generally found in quiet ponds protected from wind action.

Mechanical Control

Azolla can be controlled by raking or skimming it off the pond's surface.

Chemical Control

Broad spectrum contact herbicides, such as Ultra PondWeed Defense ®, will quickly kill Azolla. Because it does not stay in the water body, multiple treatments may be needed throughout the season.

Chemical Application Best Practices

Anytime you use chemicals treat weeds or algae, please keep in mind the following:

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Why is Azolla important?

In fact, the Anabaena – Azolla association has been shown to be of major agronomic importance for its potentiality as a biofertilizer to substitute chemical nitrogen compounds. Azolla has been used as “green manure” in several countries to fertilize rice paddies and to increase rice yields ( van Hove and Lejeune, 2002 ).

Which cell may have contributed to the determinate growth of Azolla?

Gunning (1978) suggested that the symplasmic isolation of the apical cell may have contributed to the determinate growth of Azolla. Interestingly, this is a situation opposite to that observed in the gametophyte of Onoclea just described, where the apical cell produces more plasmodesmata with each successive division.

What is the Anabaena – Azolla association?

Furthermore, the Anabaena – Azolla association is also applied as controlling agent for weeds and mosquitos, due to its ability to cover water surfaces, and for improving water quality for its properties of removing excess quantities of nitrate and phosphorous. View chapter Purchase book. Read full chapter.

What is the HIF of Anabaena?

In contrast with other plant-cyanobacterial symbioses, Azolla hormogonium initiation factors (HIFs) are unknown. A colony of Anabaena is associated with each fern shoot apex and, as the plant grows, the cyanobacterial filaments are partitioned off into each new leaf.

Is Azolla a pteridophyte?

Azolla is a small floating fern and is the only known pteridophyte that lives in symbiosis with a diazotrophic cyanobacterium. All the species of the genus harbour in their fronds a filamentous N2 -fixing cyanobacterium until now referred as Anabaena azollae (Nostocaceae) ( Papaefthimiou et al., 2008 ).

Does Azolla increase grain yield?

Increase from 14% to 40% in grain yield of rice has been reported with Azolla used as dual crop. Moreover, Azolla has a high rate of multiplication, which helps in covering very rapidly the surface of water bodies where it is growing.

Is Anabaena a legume?

Azolla – Anabaena is capable of fixing nitrogen at higher rates than legumes and is able to growth successfully in waterlogged habitats having low level of nitrogen. The Asians have recognized benefits of Azolla on rice cultivation first, since both rice crop and fern require similar environmental growing conditions.

Where did Azolla filiculoides originate?

Native to the Americas, Azolla filiculoides was introduced to the UK in the 19th century and became naturalized, going on to become widespread on slow moving and stationary water bodies, frequently infesting valuable or threatened habitats.

How long does it take for azolla to reproduce?

Over a period of two to three months, S. rufinasus feeds and reproduces extensively and brings the Azolla under control. It can be so efficient that it effectively eliminates its entire food source and adults must then fly in search of further Azolla infestations, leaving clear water bodies.

Does Azolla fix nitrogen?

With the ability to fix nitrogen through association with a symbiotic cyanobacterium, Azolla is also able to dominate in nitrogen-poor water bodies. Azolla can propagate itself vegetatively, rapidly doubling its population size in suitable conditions.

Is Azolla common in the UK?

In the UK, despite the background impact of the weevil, significant Azolla infestations were still common and difficult to control, with the weevil likely limited by cooler conditions and slow to catch up with new Azolla outbreaks.

What is an azolla plant?

What is Azolla? Azolla plants in a pond. Azolla is a floating aquatic pteridophyte (a fern) with symbiotically associated nitrogen fixing cyanobacteria ( Anabaenae azollae ). In fact it often forms green or red mats in water bodies and also has names as ‘duckweed’ and ‘fairy moss’.

How many species of Azolla are there?

Six species of Azolla are there viz:- A. carolina, A. filiculoides, A. mexicana, A.microphyla, A. nilotica and A. pinnata. Out of these Azolla pinnata is very common and good yielder in tropical climates.

What is the effect of Azolla on rice?

Reduces evaporation rate from irrigated rice fields . Capable of producing methane gas when anaerobically digested. Solublises minerals such as Zn, Mg,Fe and make it available to rice. Azolla plants acts as mosquito repellent by limiting their habitat.

How does azolla help rice?

Azolla can be used to increase rice yield by several folds at comparatively low cost and less labour. They are grown in a part of field and are transferred in the whole field, before or after transplanting.

How does Azolla look?

How does it looks? Azolla closeup view. The plants are visible as clusters of small leaf floating in ponds,wet fields,rice field and drains. While their fibrous roots floats underneath of the water.

How much rice yield increases when incorporated with Azolla?

In fact in different researches it was found that the yield of rice was increased by 20-30% when incorporated with Azolla cultivation.

Is Azolla a poultry feed?

Azolla poultry feed. Being a rich source of proteins and amino acids they are often used as a feed supplement. However it is not only limited to poultry and pigs this feed is used for other livestocks also.

Overview

Species

Ecology

Reproduction

Applications

Invasive species

Importance in paleoclimatology

Bioremediation