Overview
Letestua durissima (A.Chev.) Lecomte, commonly known as "Tibig" or "Gru-gru-an" is a species of flowering plant in the family Clusiaceae. The plant is indigenous to the Philippines and can be commonly found in lowland forests and disturbed areas.
Appearance
The plant typically grows up to 3 meters in height with a trunk that can reach up to 30 cm in diameter. The bark of the tree is grayish-brown, rough, and uneven, while the leaves are leathery, shiny, and dark green in color. The tree produces small, white, fragrant flowers that eventually develop into green, fleshy fruits that contain a single seed.
Uses
The bark of Tibig is known for its medicinal properties and is traditionally used in the treatment of various ailments such as diarrhea, bronchitis, and fever. The fruit is used for its edible pulp, which is consumed locally. The wood of Tibig is also highly valued for its strength and durability, and is often used for building and furniture making. However, the tree is facing threats due to deforestation and habitat destruction.
Light requirements
Letestua durissima is adapted to growing in shaded areas of the forest. It needs filtered sunlight or partial shade to thrive. Direct sunlight exposure can scorch the foliage and inhibit growth.
Temperature requirements
The ideal temperature range for Letestua durissima growth is between 20-25°C. Temperatures above 30°C can cause heat stress and damage the plant. At temperatures below 15°C, plant growth is inhibited.
Soil requirements
Letestua durissima prefers well-draining soils with a neutral pH (6-7). The soil must be rich in organic matter and have excellent moisture retention capacity. The plant is not tolerant of waterlogging or soils with high salinity levels. It can grow in nutrient-poor soils but may require occasional fertilization.
Cultivation Methods
Letestua durissima is a tropical plant that grows well in warm and humid conditions. It should be cultivated in well-drained soil with a pH ranging from 5.5 to 7.5. The plant prefers partial shade, and so it should be sheltered from direct sunlight. Letestua durissima is a slow-growing plant, so it is advisable to plant it in well-prepared soil with good organic content.
Watering Needs
Proper watering is crucial for the growth and survival of Letestua durissima. The plant prefers moist soil but is sensitive to overwatering. Watering should be done once or twice a week, depending on the weather conditions. In dry weather, it is essential to water the plant more frequently. On the other hand, overwatering can lead to root rot, which can be harmful to the plant. It is advisable to check the soil moisture before watering and ensure that the soil is not waterlogged.
Fertilization
Letestua durissima requires regular fertilization to maintain robust growth. A slow-release fertilizer with a balanced NPK ratio (10-10-10) is ideal for the plant. Fertilization should be done once every two months during the growing season. Over-fertilization can lead to excessive vegetative growth, which can make the plant susceptible to diseases and pests.
Pruning
Pruning is an essential aspect of Letestua durissima's care. The plant can grow up to 12 feet tall and can be pruned to maintain its shape and size. Pruning should be done during the dormant season when the plant is not actively growing. Overgrowth can be removed to encourage new growth and maintain the plant's size. Dead or diseased leaves should be pruned to prevent the spread of disease to other parts of the plant.
Propagation of Letestua durissima (A.Chev.) Lecomte
Propagation of Letestua durissima (A.Chev.) Lecomte is typically achieved through either seeds or stem cuttings.
Propagation by seeds
The seeds of Letestua durissima (A.Chev.) Lecomte require some preparation before sowing. The seeds have a hard outer coat that is impermeable to water and therefore requires scarification or soaking in water for several hours prior to planting to encourage germination. Sow the seeds in a well-draining soil mix and keep the soil moist until seedlings emerge.
Propagation by stem cuttings
Propagation by stem cuttings is a more reliable method as it results in a genetically similar plant. Take stem cuttings of about 6 inches in length, and remove all the leaves leaving only a few at the top. Dip the end of the cutting in rooting hormone and place it in a well-draining soil mix. Keep the soil moist but not wet until roots develop, and then move the plant to a larger container or to its permanent growing location.
Disease Management
Letestua durissima is susceptible to several diseases, including root rot, stem canker, and fungal leaf spot diseases.
Root rot: This disease occurs when the roots become infected with soil-borne fungi, causing them to rot. The plant may exhibit symptoms such as wilting, stunting, and yellowing of leaves. Improve drainage and avoid over-watering to prevent root rot. If the disease is already present, remove the affected parts and apply a fungicide to the remaining healthy roots.
Stem canker: Stem canker is caused by fungi and bacteria, which infect the stem of the plant. The disease can cause the plant to become stunted, dry up, and die. Prune off the affected parts of the stem and dispose of them properly. Apply a fungicide to the remaining part of the stem to prevent further spread of the disease.
Fungal leaf spot diseases: These diseases occur when the plant is infected by fungi, causing spots on the leaves. The plant may also become stunted, and the leaves may drop off if the disease is severe. Use a fungicide as a preventive measure and follow proper watering practices to prevent fungal leaf spot diseases.
Pest Management
Several pests can affect Letestua durissima, including mealybugs, spider mites, and scale insects. Effective pest management measures include:
Mealybugs: Mealybugs are small, soft-bodied scale insects that suck sap from the plant. They often gather in groups on the undersides of leaves, in leaf axils, or around stems. Use a cotton swab dipped in rubbing alcohol to remove the insects, or apply insecticidal soap to the affected areas.
Spider mites: Spider mites are tiny arachnids that feed on the plant's sap, causing yellowing, wilting, and drying of leaves. Use a strong stream of water to knock off the mites from the plant and apply a miticide to prevent further infestation.
Scale insects: Scale insects are tiny, immobile insects that attach themselves to the surface of the plant and suck sap. Symptoms of an infestation include yellowing of leaves and honeydew secretion. Use a soft brush to wipe off the scales from the plant, or apply insecticidal soap to the affected areas.
