The following are the crop details for Azolla

Scientific name: Azolla pinnata

Family: Salviniaceae

Clade: Tracheophytes

Division: Polypodiophyta

Kingdom: Plantae

Order: Salviniales

Scientific Name Azolla pinnata R. Br.

Common Name mosquito fern



Azolla is a genus of seven species of aquatic ferns in the family Salviniaceae.

They resemble duckweed or other mosses more than other conventional ferns because of how reduced and specialized they are. Only two fern species have published reference genomes, and Azolla filiculoides is one of them.

Azolla pinnata, an aquatic fern from the Azollacea plant family, is largely used as cattle fodder. With a main stem and pinnate side branches, azolla is a tiny branching plant.

The side branches are longer at the base of the stem than at the top giving the fronds a roughly triangular shape. Each frond is composed of many overlapping rounded leaves which are covered in tiny hairs on their upper surface.

Fronds are bright green in color, but they can take on a reddish tint when they are exposed to direct sunshine. On the water's surface, floated fronds resemble red velvet. Individual fronds can grow to a length of 1.5 to 2.5 cm (0.6-1.0 in).

Azolla is a plant whose native habitat stretches from Africa through India, Southeast Asia, and Australia. Other names for azolla include red azolla, feathery mosquito fern, water velvet, and African azolla.


The Azolla plant is commonly grown as a fodder plant for animals and as a companion plant for rice since it fixes nitrogen and suppresses weeds.


Basic prerequisites Azolla must be grown in freshwater or moist mud in order to flourish since if allowed to dry out, the plants will die within a few hours.

Azolla plants spread quickly and can be grown in ponds or specially constructed pits. Strong water currents could damage the plant's fronds if it is cultivated in water, hence there should be little to no current.

The ideal conditions for azolla growth are in standing water that is 4 to 7 pH and between 5 and 12 cm (2.0–4.7 in) depth. The soil at the bottom of the pond or pool shouldn't be accessible to the plant's roots because this can result in nutrient deficits.

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 first cultivated by seeding a prepared pit or pond. The azolla will rapidly colonize the water and start reproducing on its own. To enable the plant to recolonize, some of the harvest ought to be set aside.

To keep the pond from being too congested, plant materials should be collected on a daily basis.



A. pinnata is a floating aquatic fern that can be found at low to moderate altitudes on the surface of tiny, quiet ponds or backwaters without waves.

It can entirely cover the water surface in ponds in cattle paddocks and other bodies of water with high nutrient levels, where it becomes exceptionally profuse. It can survive on damp soil near rivers, ditches, and ponds, which can help the plant withstand dry conditions and low water levels.

Lowland populations in New Guinea are found between 3 and 60 meters above sea level and highland inhabitants are found between 1000 and 3000 meters above sea level.

Plants from the highlands and those from the lowlands, however, are not readily distinguishable from one another.

Biology and Ecology

The genetically known number of chromosomes in the genus Azolla is n=22, with various variants. This most likely means that the original count, which came from n=11, was a tetraploid n=22. There have been reports of n=22 in tropical Africa, n=33 in Asia, and n=44 in Australia for A. pinnata.

Tropical and subtropical regions experience year-round physiology and phenology growth.

Although there isn't a clear connection between sporulation and color change, crowding frequently causes spore reproduction as well as a change to red hue. Fronds can double in size every three days when they divide vegetatively, which causes them to expand incredibly quickly and colonize new lakes and ponds.

phosphorous shortage aids in the development of A. pinnata's red coloring. The upper leaf surfaces are completely water-repellent, and if the plant is completely buried, it swiftly floats back up on its right side. Deoxyanthocyanins are found in A. pinnata and prevent molluscs from eating on it. Biology of Reproduction by fragmenting the fronds, vegetative reproduction is accomplished.

Spores are produced during sexual reproduction and dispersed into the water. The heterosporous nature of azolla is an obvious adaption to an aquatic environment. Typically paired micro- and megasporocarps are borne in the axils of submerged lobes, basally on the branches, and are completely surrounded by a thin indusium. Sporangia are produced in sporocarps. A few of to many globose microsporangia, each bearing 32–64 microspores, are present in the big, globose microsporocarp.

A single megasporangium with a single megaspore is present in the smaller megasporocarp. Spores might be smooth, trilobate, globose, pitted, or sculptured. In the microsporangium, microspores are embedded in the outer border of a number of mucilaginous masses (massulae), each of which has several to numerous hooked (glochidiate) or unhooked, septate or non-septate processes on some or all of its sides.

Megaspore apical massulae, on occasion known as "floats," can be three or nine. criteria for the environment Although Azolla grows more quickly under eutrophic environments, nitrogen levels are not particularly significant for their development. It is particularly prevalent in (wet) rice fields in the nations of Southeast Asia.

 Utilizing the symbiotic blue-green algae's capacity for nitrogen fixation, it serves as a natural fertilizer. The cyanobacterium Anabaena azollae has a symbiotic relationship with other members of the genus. Algae inhabits the intercellular spaces of Azolla's basal leaves as an endophyte.

Heterocysts in the algal cell fix atmospheric nitrogen, which is then transported as ammonia to Azolla.

Control and Prevention

The national list of registered pesticides or the appropriate authority should be consulted to ascertain whether products are legally permissible for use in your country when contemplating chemical control due to the varying laws surrounding (de)registration of pesticides. Use of pesticides must always be legal and in accordance with the directions on the label.

Chemical Control

Applications of terbutryn, glyphosate, and diquat can kill A. pinnata. Kerosene and a wetting agent mixed together can be used for controlling A. pinnata.

Thick mats on reservoirs and slow-moving waterbodies have an adverse economic impact on water users. Agriculture, recreation, and municipal usage of water are some of those that are most severely impacted.

Impact to the Environment.

A. filiculoides grows rapidly in eutrophic water systems, easily outcompeting native plants. An anaerobic environment is produced below an A. filiculoides mat by decaying root and leaf debris and the absence of light.

In addition to very little have the ability to survive in such conditions, poor odors, color, and turbidity lower the quality of drinking water. Cases of livestock and game producers losing animals as a consequence of them refusing to drink from contaminated waterbodies or drowning as a result of mistaking the mat for solid ground have been reported.

According to reports, the weed also encourages the growth of diseases that are waterborne, water-based, and water-related, as well as increases water loss through evapotranspiration.

Impact on Biodiversity

Waterbodies up to 10 hectares in size may develop dense mats (5–20 cm thick) due to A. filiculoides infestations. It has been established that these infestations have a profound negative influence on the biodiversity of aquatic ecosystems and have significant ramifications for all facets of water use.

The eastern Cape rocky in South Africa, one of the last surviving habitats for the threatened fish species, had become so overrun with the weed that S. bainsii faced extinction if the biological control program had not been so successful.


CABI Crop Protection Compendium. (2008). Azollo pinnata datasheet. Available at: [Accessed 06 November 14]. Paid subscription required. Directorate of Animal Husbandry and Veterinary Services. (2010). Azollo as Livestock Feed. Directorate of Animal Husbandry and Veterinary Services, Cuttack, India. Available at: [Accessed 06 November 14]. Free to access. Ferentinos, L., Smith, J., Valenzuela, H. (2002). Azolla. College of Tropical Agriculture and Human Resources (CTAHR), University of Hawaii at Manoa. Available at: [Accessed 06 November 14]. Free to access.


Category : Insects

Azolla weevil (Water Fern Weevil) Stenopelmus rufinasus

Weevil feeds on Azolla and result in complete eradication of fern. So generally it is used as biocontrol agents to control Azolla in ponds and lakes.
The insect is very small measure 2.1 mm (1.8-2.3 mm) which originated in North America.
No known control measures available.

Golden apple snail Pomacea canaliculata

The snails feed during the night and at dawn on young succulent plants such as newly transplanted rice crops, weeds and Azolla.
The golden apple snails are fast growing and females can lay egg masses of up to 500 eggs per week.
Deep ploughing and harrowing during off-season kills all the snails in the soil. One must make sure that Azolla is free from apple snails and their egg when transferring from one location to another. Cayuga black ducks can use as a biocontrol agent to control snails.
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