Overview of Polyalthia crassipes Engl.
Polyalthia crassipes Engl. is a flowering plant that belongs to the family Annonaceae, which is native to Southeast Asia. The plant is commonly known by several names such as Pond Apple, Wild Apple, and Burmese Apple.
General appearance of Polyalthia crassipes Engl.
Polyalthia crassipes Engl. is a slow-growing evergreen tree that can reach a height of up to 20 meters. The bark of the tree is gray-brown, rough, and fissured. The leaves are glossy, dark green, and somewhat leathery in texture. The leaves are ovate-lanceolate, simple, entire, and are around 10-25 cm long and 4-9 cm broad. The flowers are small and are pale yellow or greenish in color. The fruit of the tree is round and has a diameter of around 4-5 cm.
Uses of Polyalthia crassipes Engl.
Polyalthia crassipes Engl. has been used by several cultures for medicinal purposes. Different parts of the plant such as the bark, leaves, and roots have been used to treat several ailments such as fever, malaria, dysentery, and diarrhea. The fruit of the tree is also edible and is used in the preparation of different dishes.
Additionally, the wood of the tree is durable and has been used in different construction and woodworking projects. The leaves of the tree are also used as a natural insecticide. The plant is also grown as an ornamental plant in gardens and parks due to its attractive foliage and beautiful flowers.
In conclusion, Polyalthia crassipes Engl. is a valuable plant due to its numerous uses. Its medicinal properties, edible fruit, durable wood, and beautiful foliage make it an important plant in different cultures.
Light Requirements
Polyalthia crassipes generally requires high levels of light but can tolerate moderate shade. It is recommended to grow the plant in bright, indirect sunlight to ensure proper growth and development.
Temperature Requirements
The plant is adapted to a warm and humid environment, making it suitable for growing in tropical and subtropical areas. It prefers a temperature range of 20-30°C (68-86°F) throughout the year. Temperatures below 15°C (59°F) or above 38°C (100°F) can be detrimental to its growth.
Soil Requirements
Polyalthia crassipes grows well in well-draining, fertile soil with a pH range of 6.0-7.5. The soil should be rich in organic matter and have good water-retention capacity. It is recommended to mix the soil with sand or perlite to improve drainage. The plant can also thrive in sandy and loamy soils but may need more frequent watering.
Cultivation Methods
Polyalthia crassipes Engl., commonly known as the "Nausikaa Tree," is native to Papua New Guinea and can grow up to 20 meters tall in the wild. The preferred cultivation method for the Nausikaa Tree is in well-draining soil, with a pH level of 6.5-7.5, moderately moist but not waterlogged. It thrives in partial sunlight and temperatures between 18-32°C.
The plant can be propagated through seeds, stem cuttings, and air layering. To propagate through stem cutting, take a well-growing branch with at least 2 leaves and a node, remove the lower leaves, dip the cut end in rooting hormone, and plant it in a well-draining medium. Cover the cutting and container with plastic to retain moisture. Roots should appear in 6-8 weeks.
Watering Needs
The Nausikaa Tree requires moderate watering but avoid waterlogging the soil, which can cause root rot. It is best to water the plant thoroughly and then allow the topsoil to dry out before watering again. During the dry season, you may need to water more frequently, ensuring that water drains well from the soil.
Fertilization
Feed Polyalthia crassipes Engl. a balanced fertilizer containing nitrogen, phosphorus, and potassium once every two weeks during the growing season. Avoid fertilizing during the fall and winter months. A low dosage of fertilizer is recommended for young plants. Fertilizing too much can lead to leaf drop and stunted growth.
Pruning
To keep the Nausikaa Tree in shape, prune it slightly after flowering in the spring or early summer. Cut any diseased, dead, or crossed branches cleanly to reduce the risk of infection. Pinching or cutting off new growth from the tips can promote bushier growth. Ensure pruning equipment is sanitized to avoid introducing diseases to the plant.
Propagation methods
Polyalthia crassipes Engl. can be propagated through various methods such as seed propagation, stem cuttings, and air layering.
Seed propagation
Seeds of Polyalthia crassipes Engl. are small and have a hard seed coat. To enhance germination, the seeds should be soaked in warm water for about 24 hours before sowing. After soaking, plant the seeds in well-draining soil and water regularly. The seedlings will emerge within two to four weeks. However, seed propagation may take longer to reach maturity, usually up to four years.
Stem cuttings propagation
Stem cuttings are an effective way to propagate Polyalthia crassipes Engl. Take cuttings from the tips of young shoots with a length of about 10 -15 cm and about 0.5- 1 cm in diameter. Remove the lower leaves and dip the cuttings in rooting hormone powder. Next, plant the cuttings in a well-draining soil mix and water regularly. Keep the cuttings in shade and humid conditions until roots and shoots develop. Transplant to a more permanent location once they are established.
Air layering propagation
Air layering is a propagation method commonly used for larger plants and can be done in spring or summer. To propagate Polyalthia crassipes Engl. using air layering, select a healthy branch and remove a section of the bark from approximately 15 cm in length. Place a ball of moist sphagnum moss around the exposed area and cover it with plastic. The moss should remain wet, and the plastic should be sealed tightly with a tie or tape. Once roots have developed, usually within two to three months, cut off the branch below the new roots and transplant.
Disease Management
Polyalthia crassipes Engl. commonly suffers from various diseases that affect its growth and reduce the quality of its fruits and leaves. The following are some of the common diseases that affect Polyalthia crassipes and ways to manage them.
Fungal diseases
Fungal diseases such as anthracnose and leaf spot are common in Polyalthia crassipes. The symptoms include leaf spots, blackening, and wilting of the leaves.
The best way to manage fungal diseases is to maintain good plant hygiene by removing and destroying infected plant parts. Additionally, you can apply fungicides at regular intervals to prevent the spread of the disease. Fungicides such as copper-based compounds and chlorothalonil are effective in managing fungal diseases.
Bacterial diseases
Bacterial diseases such as bacterial wilt and leaf blight are also common in Polyalthia crassipes. The symptoms include wilting, yellowing, and necrosis of the leaves.
The best way to manage bacterial diseases is to maintain good plant hygiene by removing and destroying infected plant parts. Additionally, you can apply copper-based fungicides at regular intervals to prevent the spread of the disease.
Pest Management
Polyalthia crassipes is also susceptible to pest infestations. The following are some common pests that affect Polyalthia crassipes and ways to manage them.
Scale insects
Scale insects are common pests that suck the sap from the leaves, causing them to wilt and yellow. You can manage scale insects by pruning and destroying heavily infested plant parts and applying horticultural oil to the remaining plant parts.
Mites
Mites are also common pests that affect the leaves of Polyalthia crassipes. The symptoms include yellowing and drooping of the leaves.
The best way to manage mites is to maintain good plant hygiene by removing and destroying infected plant parts. Additionally, you can apply miticides such as abamectin and bifenazate at regular intervals to prevent the spread of the pest.
Caterpillars
Caterpillars are pests that feed on the leaves of Polyalthia crassipes, causing defoliation and stunted growth. You can manage caterpillars by manually removing and destroying them or applying Bacillus thuringiensis-based insecticides.
