Origin
Popowia macrocarpa Engl. & Diels, commonly known as the Thai custard apple or Cau apple, is a plant species that belongs to the Annonaceae family. It is indigenous to Thailand where it is mainly found in the southern part of the country.
Common Names
The plant has several common names, including Thai custard apple, Cau apple, popowia, and wild atemoya. In Thailand, it is called "ma-khwit" in Thai language which means "sweet wood apple".
Uses
The fruit of Popowia macrocarpa is edible and has a sweet, custard-like flavor. It is often consumed fresh or used in desserts such as ice cream, cakes, and custards. The plant has also been traditionally used for its medicinal properties. The roots and leaves are known to have antipyretic, anti-inflammatory, and analgesic effects and are used to treat various ailments such as fever, headaches, and rheumatism.
General Appearance
Popowia macrocarpa is a small, evergreen tree that can grow up to 15 meters in height. It has a dense, rounded crown with glossy, dark green leaves that are oblong to lanceolate in shape. The tree produces small, inconspicuous flowers that are greenish-yellow in color. The fruit is a large, oblong, or ovoid berry that is 7-20 cm long and 3-10 cm wide. It is green when unripe and turns yellow-green or brown when ripe. The fruit contains numerous small, black seeds embedded in white or pale yellow pulp that is soft and creamy in texture.
Growth Conditions of Popowia macrocarpa Engl. & Diels
Light: Popowia macrocarpa is a shade-loving plant that thrives in partial to full shade, ideally under a forest canopy. It cannot tolerate direct sunlight, which may cause leaf scorching and stunt growth.
Temperature: The plant is native to tropical and subtropical regions and requires warm temperatures between 20°C and 30°C for optimal growth. It cannot survive in freezing temperatures and is best grown in USDA hardiness zones 10 to 11.
Soil: Popowia macrocarpa prefers well-draining soils that are rich in organic matter and slightly acidic with a soil pH between 5.5 and 6.5. It cannot tolerate waterlogged soils, which may cause root rot. Therefore, the soil should have good drainage to avoid waterlogging. This species requires soils that are rich in organic matter and have good moisture retention capacity.
Fertilizer: The plant is not a heavy feeder, and excessive fertilization may cause harm to the plant. Using slow-release fertilizers rich in organic matter is ideal. Applying fertilizers once every three months will suffice to provide the necessary nutrients.
Water: Popowia macrocarpa requires regular watering, particularly during dry spells. Watering the plant once a week is sufficient, depending on the weather and soil moisture content. The plant will benefit from a regular misting, particularly during drier periods, to maintain adequate humidity levels, which can facilitate its growth.
Propagation: The most effective method of propagating Popowia macrocarpa is through seedlings, stem cuttings, and root division. However, seed propagation is recommended because it is more reliable and propagates the plant quickly. Seed germination should be done in a porous propagation medium in a warm shaded area, where the new growth should be protected from direct sunlight.
Conclusion
In conclusion, providing the ideal growth conditions for Popowia macrocarpa Engl. & Diels is essential to its development and survival. Maintaining the right temperature, light, soil, water, and fertilizer conditions must be closely monitored to optimize growth. With the right balance of these elements in its growth conditions, the plant can thrive and provide many benefits.Cultivation Methods
Popowia macrocarpa, also known as keledang in Indonesia, is a tropical plant that thrives well in warm and humid climates. It can be grown both indoors and outdoors, in a well-draining soil mix that contains a reasonable amount of organic matter.
The plant requires partial shade to thrive, and it is advisable to place it in an area where it can receive indirect sunlight or shade for most of the day. Ensure that the temperatures remain between 60-85°F (15-29°C), and avoid exposing it to cold drafts.
When planting, create a hole that is 2-3 times the size of the root ball, and backfill the soil around the root ball, ensuring that there are no air pockets. Water the plant thoroughly and avoid placing it too deep in the soil.
Watering Needs
Popowia macrocarpa requires consistent moisture levels to thrive, but it is essential to avoid overwatering. The plant prefers slightly moist soil, and it is best to water it when the soil feels slightly dry to the touch.
Avoid letting the soil dry out completely as it may cause the plant to wilt and become vulnerable to pest infestations and diseases.
The quantity of water required by the plant will also depend on environmental factors, such as humidity levels, temperature, and sunlight exposure. Always refer to the plant's moisture meter to determine when to water the plant.
Fertilization
To enhance the growth of Popowia macrocarpa, it is advisable to fertilize it regularly with a balanced and water-soluble fertilizer. Apply the fertilizer once a month, but be cautious not to over-fertilize, as it may lead to salt buildup or root damage.
Avoid fertilizing the plant during winter when it is dormant, as it may lead to fertilizer burn and adversely affect its growth.
Pruning
Pruning Popowia macrocarpa not only enhances its appearance, but it also promotes healthy growth by stimulating the production of new branches and leaves. Begin by removing any wilted, dead, or yellow leaves, as well as any crossing branches or stems.
You can also prune the plant to manage its height and shape. But keep in mind that the plant may take time to recover after pruning, and it is advisable to only do it when necessary.
Prune the plant during spring or summer, before the growth spurt begins, to avoid stunting its growth. Use sterilized pruning shears to avoid spreading diseases, and always cut close to the main stem or growth node to promote healing.
Propagation of Popowia macrocarpa
Popowia macrocarpa, also known as the Kepel fruit tree, can be propagated through various methods.
Seed Propagation
The most common propagation method for Popowia macrocarpa is through seed propagation. The seeds can be collected from mature fruits that have fallen off the tree. The seeds should be extracted from the pulp and washed with water to remove any remaining pulp residues. Afterward, the seeds should be dried under shade for two to three days to prevent damage from the sun's heat.
Popowia macrocarpa seeds have a low germination rate, and it can take several months for the seeds to germinate. Sowing the seeds in a mixture of sand and peat and keeping them moist and under shade is recommended. Germination can take anywhere from two to six months, and it is important to weed and water the seedlings regularly.
Air Layering
Air layering is a propagation method that is commonly used for plants that are difficult to grow from cuttings or have a low success rate with seed propagation, like Popowia macrocarpa.
To propagate Popowia macrocarpa through air layering, a branch is selected, and the bark is partially removed. A rooting hormone is applied to the exposed area, and the wound is wrapped with damp sphagnum moss. Afterward, the moss is covered with black plastic and tied at both ends to prevent moisture loss.
Roots will form at the wounded area, and after a few months, the newly rooted section of the branch can be severed from the parent plant and replanted.
Grafting
Grafting is another method of propagation that can be used for Popowia macrocarpa. Grafting involves joining a piece of one plant onto another, creating a new plant that has the desired qualities of both.
A scion is taken from the parent tree and is grafted onto a rootstock. The rootstock determines the tree's size and vigor, while the scion contributes to the fruit characteristics.
After the graft is complete, the tree is kept under shade and watered daily until it has established itself. It is important to note that grafting should be done by experienced individuals, as it requires precise cuts and a lot of patience.
Disease Management
Popowia macrocarpa is a relatively healthy plant, but it may still suffer from various diseases. The tree is susceptible to anthracnose or leaf spot, which presents as dark, water-soaked spots on the leaves. To manage this issue, you can apply copper fungicides, remove infected leaves, and improve air circulation by spacing out the trees.
In addition, the tree may suffer from powdery mildew, which presents as a white powdery substance on the leaves. You can manage this issue by applying sulfur-based fungicides, maintaining proper air circulation, and regularly trimming away infected leaves.
Furthermore, Popowia macrocarpa may also suffer from root rot, which typically occurs as a result of overly moist soil. To manage this issue, you can reduce watering and improve drainage by introducing organic matter into the soil.
Pest Management
Popowia macrocarpa is relatively resistant to insect pests, but can be vulnerable to some pests. One of the most common insects that may attack the tree is the scale insect, which is usually found on the leaves and stems. You can manage this issue by applying horticultural oil or insecticidal soap. Additionally, pruning away infected branches may be helpful.
The plant may also encounter mealybugs, which appear as small white cottony masses or webbing on the leaves. To manage this issue, you can apply insecticidal soap sprays or introduce natural predators like ladybugs or lacewings to your garden. Pruning away infested branches may also be helpful.
Lastly, spider mites can invade the Popowia macrocarpa tree, which is usually indicated by yellowed or stippled leaves. To manage this issue, you can introduce natural predators like predator mites or ladybugs and use insecticidal sprays. Regularly spraying the tree with water can also help prevent spider mites from infesting.
