Common Use Of Duckweed (Duck Weed)

Part A:

Introduction:

Common name : Duckweed (Duck Weed)

Latin name : Spirodela; Landoltia; Lemna; Wolffiella; Wolffia

Family name : Araceae

Common duckweed is a very small light green free-floating, seed bearing plant. Duckweed has 1 to 3 leaves, or fronds, of 1/16 to 1/8 inch in length. A single root (or root-hair) protrudes from each frond. Duckweeds tend to grow in dense colonies in quiet water, undisturbed by wave action. A lot of the time more than one species of duckweed will be growing together in these colonies. Duckweeds can be aggressive invaders of ponds and are often found mixed in with mosquito fern or water meal. If colonies cover the surface of the water, then oxygen depletions can kill fish. These plants should be controlled

Moderate conditions of temperature and light and a liquid medium with the necessary nutrients are essential for good growth. Fortunately, duckweeds adapt well to a wide range of conditions and are easy to grow.

Duckweeds can be grown in the pond water from which they were collected in open containers. It is important to replace the water frequently, since evaporation will result in concentration of salts. Using open containers prevents overheating if you place the containers outside or in a sunny window. In nature duckweeds grow in water from many sources and compositions.

It is important to keep your duckweed cultures clean. If you collect fresh duckweed specimens from nature, the water will contain a variety of other organisms. These will include bacteria, fungi, algae, protozoa, and even small multi-cellular animals and insect larvae. You can clean up your duckweed cultures by transferring the plants individually to clean fresh water. Remove damaged and aged (yellow or white) fronds from your cultures as they appear.

The plant and its

These colonies will also eliminate submerged plants by blocking sunlight penetration. Many kinds of ducks consume duckweed and often transport it to other bodies of water. http://aquaplant.tamu.edu/plant-identification/alphabetical-index/common-duckweed/ Duckweeds grow at water temperatures between 6 and 33°C. Many species of duckweed cope with low temperatures by forming a turion (underground or water bud) and the plant sinks to the bottom of a lagoon where it remains dormant until warmer water brings about a resumption of normal growth.

Duckweeds have structural features that have been simplified by natural selection. A duckweed leaf is flat and ovoid. Many species have many branching roots which function as a stability organ and which tend to lengthen as mineral nutrients in water are exhausted.

Compared with most plants, duckweed leaves have little fibre (5% in dry matter of cultivated plants) as they do not need to support upright structures. Roots, however, appear to be more fibrous. As a result the plant has little or no indigestible material even for monogastric animals. This contrasts with many crops such as soya beans, rice, or maize, where approximately 50% of the biomass is in the form of high fibre, low digestibility