Ottelia Exserta (ridl.) Dandy

Overview

Ottelia exserta (Ridl.) Dandy is a type of aquatic plant that belongs to the family of Hydrocharitaceae. It is commonly known as the Shoreline swordplant or Thin leaved ottelia. It is commonly found in freshwater rivers and lakes and it is considered to be a significant part of many aquatic ecosystems.

Origin and Distribution

Ottelia exserta is widely distributed in tropical and subtropical regions of Southeast Asia, which includes Thailand, Malaysia, Indonesia, Brunei and Philippines, where the habitat of the plant is fresh water river systems and lake. The plant has also been seen in other parts of the world such as in Australia, where it is considered to be an invasive species.

General Appearance

Ottelia exserta is a perennial aquatic plant, that usually grows up to 20-50 cm tall. The plant has elongated, narrow leaves that grow up to 60 cm long and 2 cm wide, which gives the plant a grass-like appearance. It has white, delicately-veined petals and a yellow center, which gives the plant a pleasant aesthetic value. The plant has a fibrous root system and grows in dense clusters, forming a mat of vegetation on the surface of the water.

Uses

Ottelia exserta is used for various purposes such as for ornamental purposes in aquariums and ponds, and as a food source for herbivorous fish. It is also used for traditional medicine in several countries such as Malaysia and Indonesia, where it is believed to alleviate stomach ache and constipation. Apart from its medicinal value, it is also used as a natural water purifier, where the water in which the plant is grown in is cleansed by the plant which absorbs toxins and nutrients found in the water.

Light Requirements

Ottelia exserta (Ridl.) Dandy requires full sun exposure to grow optimally. This plant thrives well in areas where it receives direct sunlight for at least six hours a day. Without proper exposure to sunlight, the plant tends to grow weak, lanky, and tall.

Temperature Requirements

This plant is best grown in areas with warm temperatures. The ideal temperature range for the growth of Ottelia exserta (Ridl.) Dandy is 25-35 degrees Celsius. This temperature helps the plant to develop its roots and grow vigorously. Temperatures below 20 degrees Celsius and above 40 degrees Celsius can stress the plant and slow its growth rate.

Soil Requirements

The soil for growing Ottelia exserta (Ridl.) Dandy should be rich in nutrients and well-drained. This plant requires slightly acidic soils with a pH range of 6.5 to 7.5 for proper growth. Sandy loam and clay loam soils are the best soil types that support the growth of this plant. It is also important to ensure that the soil is hydrated consistently.

Cultivation methods for Ottelia exserta (Ridl.) Dandy

Ottelia exserta (Ridl.) Dandy is a freshwater aquatic plant native to Southeast Asia. Cultivating this plant requires a few steps that need to be followed carefully to ensure optimal growth and development. The following are some of the cultivation methods for Ottelia exserta (Ridl.) Dandy:

• Choose a location with plenty of sunlight as the plant requires adequate sunlight for photosynthesis.
• Prepare the aquatic pot or container by filling it with freshwater and adding aquatic fertilizer.
• Transplant the plant into the container by gently removing it from its former container and placing it into the new container, ensuring that the roots are covered with soil.
• Place the container in an area with a temperature range of 22 - 28 degrees Celsius, which is suitable for the plant's growth.

Watering Needs for Ottelia exserta (Ridl.) Dandy

Watering is an essential part of cultivating Ottelia exserta (Ridl.) Dandy as this plant thrives in freshwater habitats. Here are the watering needs for Ottelia exserta (Ridl.) Dandy:

• Ensure that the plant is submerged in the freshwater at all times, and the water level should be maintained between 5-15 cm above the soil line.
• Change the water frequently to avoid stagnation or the buildup of harmful chemicals that could harm the plant.
• During hot and dry seasons, top up the water frequently to maintain the required level.

Fertilization of Ottelia exserta (Ridl.) Dandy

Fertilization is essential for the optimal growth and development of Ottelia exserta (Ridl.) Dandy. Here are some fertilizer needs:

• Use aquatic plant fertilizer as it provides the necessary nutrients required for aquatic plants such as Ottelia exserta (Ridl.) Dandy.
• The recommended dosage is 2-3 tablespoons for every 15 liters of water, applied every three weeks.
• Be cautious of the application rate to avoid fertilizer burn, which can damage the plant.

Pruning of Ottelia exserta (Ridl.) Dandy

Pruning is an essential aspect of keeping Ottelia exserta (Ridl.) Dandy healthy and attractive. Pruning of the plant involves:

• Remove any damaged, diseased, or wilted leaves or stems to prevent the spread of infection to the rest of the plant.
• Prune the plant to control its size and shape, ensuring it does not overgrow and crowd other aquatic plants in the container.
• The pruned pieces can be used for propagation by planting in separate containers with freshwater.

Propagation of Ottelia exserta (Ridl.) Dandy

Ottelia exserta (Ridl.) Dandy, commonly known as the Malayan Frog's Lettuce, is an aquatic plant native to Southeast Asia. It is a popular choice for aquatic gardeners and is easy to propagate. There are two main propagation methods for Ottelia exserta, which include:

1. Division

Division is the easiest and most common method of propagation for Ottelia exserta. This method involves dividing the plant into smaller sections and planting them separately. This can be done during the plant's active growth period, typically in the spring or summer, when the plant has developed new growth.

To propagate Ottelia exserta by division, follow these steps:

1. Carefully remove the plant from its container or pond, taking care not to damage the roots.
2. Separate the plant into smaller sections, making sure each section has some roots and leaves.
3. Plant each section in a separate pot or area of the pond, making sure the roots are fully submerged in water.
4. Water the newly planted sections thoroughly and regularly to encourage root growth.

2. Seeds

Propagation of Ottelia exserta can also be done with seeds. This method requires a little more patience and care, but can be a fun way to grow new plants.

To propagate Ottelia exserta by seeds, follow these steps:

1. Collect mature seeds from the plant, which are typically produced in the fall or winter.
2. Clean the seeds by removing any residue or debris.
3. Place the seeds in a container of water and let them soak for 24 hours.
4. Remove the seeds from the water and place them on a wet paper towel, rolling the towel up to keep the seeds moist.
5. Place the rolled up paper towel with the seeds in a warm, well-lit location for germination. Keep the paper towel moist at all times.
6. Once the seeds have sprouted and developed roots, plant them in pots or directly into the pond.
7. Keep the new plants well-watered until they become established.

Propagation of Ottelia exserta can be done with both division and seeds. Both methods have their advantages and disadvantages but can result in a beautiful and healthy aquatic garden.

Disease and Pest Management for Ottelia Exserta

Ottelia exserta (Ridl.) Dandy is a plant species that belongs to the family of Hydrocharitaceae. Although it is a sturdy plant, it can be susceptible to certain diseases and pests. Understanding these diseases and pests and how to manage them is vital to keeping your Ottelia exserta healthy and thriving.

Common Diseases

The most common diseases that can affect Ottelia exserta are fungal diseases such as brown spot and root decay. Brown spot appears as small brown lesions on the leaves, which eventually turn yellow in the center and have a reddish-brown margin. Root decay, on the other hand, occurs when the roots of the plant begin to rot, often due to over-watering. Wilting of the leaves and stunted growth are indicators of root decay.

Pest Management

One pest that can pose a problem to Ottelia exserta is the aquatic snail. Snails tend to feed on the leaves and stem of the plant and can cause extensive damage if not addressed promptly. Another common pest is the water lily beetle. The beetle lays its eggs on the leaves, and the larvae damage the foliage.

Disease Management

To manage fungal diseases, it is essential to prevent the plant from becoming waterlogged and to remove any affected leaves and stems immediately. Fungicides can also be used to control the spread of the disease. Root decay is best managed by ensuring that the soil is well-draining and not excessively watered.

To manage snail infestations, copper barriers can be placed around the plant to discourage them from climbing aboard. Additionally, introducing snail-eating fish or ducks to the pond or water body can keep the snail population under control. For water lily beetles, manual removal of the larvae and eggs, or the use of insecticides, may be necessary.

Implementing effective disease and pest management practices is crucial for the health of Ottelia exserta. Constant monitoring and addressing any issues that arise promptly will ensure that the plant continues to thrive and contribute to a healthy ecosystem.