"Duckweed" or "bayroot" are aquatic plants which float on or just beneath the surface of still or slow-moving fresh water bodies. These plants are very simple, lacking an obvious stem or leaves. They consist of a small 'thalloid' or plate-like structure that floats on or just under the water surface, with or without simple rootlets. Often are classified as the subfamily Lemnoideae within the Araceae. Classifications created prior to the approximate end of the twentieth century tend to classify them as a separate family, Lemnaceae
How to grow duckweeds?
Growing duckweeds is like growing any other plant. Moderate conditions of temperature and light and a liquid medium with ...view middle of the document...
Remove damaged and aged (yellow or white) fronds from your cultures as they appear.
Native populations of duckweeds may be mixtures with varying genetic compositions. For serious work it is advisable to start cultures from a single clone. This will help increase uniformity for experimental work. It is easy to clone duckweeds.
How does duckweed reproduce?
Reproduction is mostly by asexual budding, but occasionally three tiny 'flowers' consisting of two stamens and a pistil are produced and sexual reproduction occurs.
Duckweed in the real world!
Duckweeds have received research attention because of their great potential to remove mineral contaminants from waste waters emanating from sewage works, intensive animal industries or from intensive irrigated crop production. Duckweeds need to be managed, protected from wind, maintained at an optimum density by judicious and regular harvesting and fertilised to balance nutrient concentrations in water to obtain optimal growth rates. When effectively managed in this way duckweeds yield 10-30 ton DM/ha/year containing up to 43% crude protein, 5% lipids and a highly digestible dry matter.
Duckweeds have been fed to animals and fish to complement diets, largely to provide a protein of high biological value. Fish production can be stimulated by feeding duckweed to the extent that yields can be increased from a few hundred kilograms per hectare/year to 10 tonnes/ha/year.
Mature poultry can utilise duckweed as a substitute for vegetable protein in cereal grain based diets whereas very young chickens suffered a small weight gain reduction by such substitution. Pigs can use duckweed as a protein/energy source with slightly less efficiency than soyabean meal.
Little work has been done on duckweed meals as supplements to forages given to ruminants, but there appears to be considerable scope for its use as a mineral (particularly P) and N source. The protein of duckweeds requires treatment to protect it from microbial degradation in the rumen in order to provide protein directly to the animal.
The combination of crop residues...