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''Duckweed can be eaten by chickens, ducks and pigs and can supply all of the protein needs for locally adapted breeds."''
= Specific Uses =
Depending on strain and growing conditions, duckweeds can have very high protein content of up to 50% of dry mass. High levels of vitamins are also present. The taste is remotely similar to spinach. Duckweeds have historically played a role in some east Asian cuisines (''Wolffia'' genus). Because of rapid growth and ease of cultivation, duckweeds for consumption by animals and humans are now getting more attention. Current uses as animal fodder are mostly as fish food (carp, tilapia) and bird food (chicken, duck). Possible uses as part of a human diet are still vastly under-explored.
Duckweed produces biomass faster than any other flowering plant. It has clear potential as an alternative for biofuel production.
Duckweeds are used for the detection of heavy metals and organic contaminants. A variety parameters can then be measured to assess the health of the plants: growth rate, leaf size and color, root size etc.
Duckweed is very efficient at cleaning water. First it will remove all macronutrients. Then it will remove micronutrients. Finally it will remove all metal ions, including toxics and radioactives. As such, it can be used to 'polish' industrial effluent, pre-treat sewage, denitrify effluent from other aquaculture activites and other nitrogen drainange situations (stock lots, etc.). [http://www.p2pays.org/ref/09/08875.htm Article below on Duckweed Aquaculture] addresses this topic, and there is little doubt more academic studies of duckweed as a hyperaccumulator will be forthcoming.
Duckweeds are excellent concentrators of nitrogen and phosphates. They could be used for [http://en.wikipedia.org/wiki/Biomining bio-mining]. They can pull minerals out of solution down to just trace concentration. The harvested duckweeds can then enter into a nutrient cycle which may include animal food, biogas digester etc. This way, phosphorus and other nutrients could be bio-accumulated from muddy water even in regions with generally phosphorus-deficient soils.
= Challenges =
A full layer of duckweed will block out most sunlight from deeper levels of a pond. Therefore, algal blooms are eliminated - a desired effect. However, the lack of sunlight at those deeper levels may also lead to low-oxygen conditions. As a result, anaerobic bacteria may proliferate, making the plants unsuitable as food for humans. An aeration device such as airstone may then be required. It is important not to agitate the surface, as duckweeds grow best on very quiet water.
= Ideas and applications =
*food for fish (e.g. tilapia), chicken, pigs,
= New Strains =
[insert here: information on new breeds, optimized for specific uses, higher yields, more lipids, different taste, more specific bio-accumulation etc.].
The duckweed genome is expected to be
fully [http://news.rutgers.edu/medrel/news-releases/2008/07/duckweed-genome-sequ-20080707 sequenced by the end of 2009]. This should greatly improve our understanding of duckweed biology and will likely accelerate genetic research on these plants.
= Links =