Presentation on theme: "Duckweed Not just for ducks. Duckweed Lemma minor Duckweed is an oval shaped plant that floats on the surface of water."— Presentation transcript:
Duckweed Not just for ducks
Duckweed Lemma minor Duckweed is an oval shaped plant that floats on the surface of water
Roots Roots to 15 cm
Reproduces by seed and vegetatively, thought during the growing season, nearly all plants arise by vegetative reproduction.
Each duckweed frond contains buds from which more fronds may grow. Rapidly growing plants often have three or four attached fronds.
The air pockets of duckweeds provide buoyancy, much like the air spaces in a rubber raft.
budding plant showing swollen underside with enlarged air spaces (
Usually a Variety of Species
Duckweed produces more protein per square meter than soybeans. Duckweed can be used to feed fish, shrimp, poultry and cattle. Duckweed can purify and concentrate nutrients from wastewater (sewage effluent). Duckweed provides food for wildlife, especially waterfowl.producesfish shrimppurify
a duckweed treatment lagoon inside a plastic greenhouse.
Duckweed can be used as bioremediation in wastewater
Contain twice the protein, fat, nitrogen, and phosphorus of other plants.
Can you name some biotic and abiotic factors that would influence the rate of growth of the duckweed in a pond or in the classroom? LightFish TemperaturepH Water amount rainfall Insects
Which of the following growth curves do you think will illustrate the growth pattern of a small population of duckweed introduced into a container and left to grow for two weeks?
LAB: Effect of pH on Growing Duckweed You need to know what will help grow and what would hurt the duckweed
TIPS Duckweed spreads rapidly across quiet bodies of water rich in nutrients Grows best in water with high levels of nitrogen and phosphate. Iron is often limiting.
pH Can tolerate a wide pH range, but survives best between 4.5 and strong acid weak acid 7-neutral 9-weak base strong base
TIP Grows in full sunlight as well as dense shade. Can use fluorescent fixtures (cooler than direct sunlight)
BE CAREFUL Duckweed plants are delicate and easily damaged by fingers, forceps and other instruments. may be picked up and moved without damage using a bacteriological loop
Use Pond Water Or tap water that has been de-chlorinated And added Peters Liquid Fertilizer
GROW FOR 2 WEEKS Grow in a Petri Dish Different pH in each Add water if low Count fronds Record Graph Which pH is best?