Wolffia Globosa auct.
Wolffia globosa auct., commonly known as Asian watermeal, is a species of the aquatic plant in the duckweed family. The plant is native to Asia, specifically in Japan, Indonesia, the Philippines, and Thailand. It is also present in parts of Africa, Australia, and various countries in South America.
Common Names
The plant is commonly called Asian watermeal, duckweed, or minute duckweed. Other names include seven brothers, seven pieces, seven brothers and sisters, and water lentils.
Appearance and Uses
The plant is the smallest flowering plant in the world and grows in clusters of two to three. It is oval-shaped, approximately 0.5-1.5 mm long and 0.5-1.0 mm wide, and has a single root that is 1-2 mm long. Its surface is green in color and covered with a waxy cuticle, which helps keep the plant afloat on the water.
Wolffia globosa auct. has many uses, such as a food source for animals, a source of biofuel, and in water treatment. The plant is commonly consumed by fish, birds, and some insect species, and it is an excellent source of protein, vitamins, and minerals. It has also shown potential as a biofuel source because it has a high starch content, making it an attractive option for the production of ethanol and biodiesel. Additionally, Wolffia globosa auct. has been used in water treatment to reduce nutrient levels in ponds and lakes, making it an effective natural tool for improving water quality.
Light Requirements
Wolffia globosa auct. plants require ample sunlight to grow properly. They thrive in bright light conditions and prefer direct sunlight exposure for at least six hours a day. Therefore, it is best to place the plants in an area exposed to full sunlight with no shade, such as a water body receiving unfiltered light.
Temperature Requirements
Wolffia globosa auct. is highly adaptable to various temperature ranges but grows best in warm water bodies. The ideal temperature range for growth is between 20-25 °C, although the plant can survive up to 35°C. During winter, the plants go dormant and survive better in water that is not freezing.
Soil Requirements
Wolffia globosa auct. grows very well in rich organic soils; however, they are primarily aquatic and do not grow in soil. The plant is a floating aquatic species that lives on the surface of the water and does not require any soil to grow. The plant has no roots, and its leaves absorb nutrients directly from the water, making it crucial to grow it in clean, nutrient-rich water bodies.
Cultivation Methods for Wolffia Globosa Auct.
Cultivating Wolffia globosa auct. requires a small water body with slow-moving water. A container with a depth of 10-15 cm is enough to grow this plant. Alternatively, you can make PVC boxes and fill them with water to grow this plant.
This plant is usually grown in the tropics and subtropics with a temperature range of 25-30 °C and a pH range of 5.5-7.5. Therefore, you may need a heater to maintain the appropriate water temperature if you live in a colder region.
Watering Needs for Wolffia Globosa Auct.
Wolffia globosa auct. thrives in water bodies that are clean and rich in nutrients, with a pH of 5.5-7.5. Watering for this plant is a different process since it is an aquatic plant. The water must fully cover the plant, and the plant requires a daily exchange of the water.
You can use a skimmer to remove any debris on the surface of the water, which can cause algae growth and clog the oxygen/ozone system. The water needs to be changed every week to make the necessary nutrients for the plant available.
Fertilization for Wolffia Globosa Auct.
Wolffia globosa auct. requires essential minerals for its growth. Since it grows in water, fertilization is vital to support its growth.
The most appropriate fertilizer for this aquatic plant is a nitrogen-based fertilizer such as soluble urea. You can also use other fertilizers that provide the necessary nutrients such as phosphorous and potassium at low levels.
Pruning for Wolffia Globosa Auct.
Pruning Wolffia globosa auct. is not always necessary since the plant is tiny and grows in water. Its growth habits do not require pruning to improve flowering or fruiting. However, if the plant becomes too dense, it can be thinned out manually by removing some plants, particularly the larger ones to maintain the plant's algae ratio.
Clean the plant regularly to eradicate debris and dead plants. Remove any blocks that may hinder proper plant growth.
Propagation of Wolffia globosa
Wolffia globosa is a free-floating aquatic plant that reproduces vegetatively, meaning it produces clones of itself. The plant can quickly colonize ponds, lakes, and slow-moving streams, making it an efficient wastewater treatment plant due to its ability to remove nitrogen and phosphorous from the water.
Division
The most common way to propagate Wolffia globosa is through division. The plant is typically divided by hand, and each fragment is carefully placed in shallow water with plenty of sunlight. The plant can be divided any time from early spring to late summer because it reproduces vegetatively, meaning it does not flower.
Runners
Another method of propagation for Wolffia globosa is through runners. This method works similarly to the division method, except the plant sends out runners that develop a new plantlet at the end. The plantlet can be left to grow, or it can be harvested and placed in a suitable location.
Tissue culture
Finally, tissue culture is a more advanced propagation method that involves taking small tissue samples from the plant and placing them into a growth medium that contains the necessary nutrients and hormones for the plant to grow. This method is commonly used in research settings, where large quantities of plants are needed for study purposes.
Disease and Pest Management for Wolffia Globosa Auct.
Wolffia globosa auct., commonly known as watermeal, is a floating aquatic plant that is often used for phytoremediation purposes. However, like any other plant, it is prone to diseases and pest infestations. Here are some common issues and ways to manage them:
Diseases
Watermeal is susceptible to various plant diseases such as:
- Root rot: Caused by Phytophthora species, root rot can damage the roots of Wolffia globosa and prevent them from absorbing water and nutrients. To manage root rot, avoid overwatering the plant and ensure good soil drainage. Additionally, treat the diseased plants with a fungicide.
- Leaf spot: Leaf spot is caused by fungal pathogens that attack the leaves of Wolffia globosa. Symptoms of leaf spot include white or brown spots on the leaves that gradually expand. To manage leaf spot, avoid overhead watering and improve air circulation around the plants. Use a fungicide to treat the infected plants.
- Smut disease: The fungal pathogen Ustilago wolffiae can cause smut disease, which affects the inflorescences of Wolffia globosa. Infected plants can develop malformed reproductive structures and reduced growth. To manage smut disease, remove and destroy the infected plants and treat the remaining plants with a fungicide.
Pests
Wolffia globosa is also susceptible to pest infestations, including:
- Waterfowl: Ducks, geese, and other waterfowl species can feed on Wolffia globosa, reducing the plant's biomass. To manage waterfowl damage, install a protective fence around the plant growing area, or use decoys or loud noise to discourage the birds.
- Snails: Snails can consume large amounts of Wolffia globosa, causing significant biomass reduction. To manage snails, remove any debris from the water surface, use copper strips to repel the snails, or introduce natural predators such as crayfish or fish.
- Insects: Various insects such as water mites, beetles, and midges can feed on Wolffia globosa and impact its growth. To manage insect infestations, remove any weeds or debris from the water surface, and use insecticides specifically designed for aquatic plants.
By following these disease and pest management strategies, you can help ensure the health and vitality of your Wolffia globosa auct. plants, enhancing their potential benefits in phytoremediation and other applications.
