Harungana robynsii Spirlet: General Appearance
Harungana robynsii Spirlet is a small tree that belongs to the family of Hypericaceae. It can grow up to 12 meters tall at full maturity and has a straight, cylindrical trunk that measures around 30 cm in diameter. The branchlets are greenish-brown and have a lenticellate surface, while the leaves are simple, opposite, and measures about 7.5-25 cm long and 5-12 cm wide. The tree blooms small white flowers that grow in clusters that are about 2.5-3 cm long and have a sweet fragrance.
Harungana robynsii Spirlet: Origin and Common Names
The Harungana robynsii Spirlet is native to Madagascar and can be found in the forest areas of the island. It is known by several common names, including "Vohimena," "Ody," "Fihezan-draha," and "Soasoa." In Madagascar, the tree is also used as a traditional medicine for various purposes, including the treatment of fever, burns, and skin irritations.
Harungana robynsii Spirlet: Uses
In addition to its medicinal uses, Harungana robynsii Spirlet also has other practical applications. The tree's wood is used for carpentry and furniture-making, while the bark is sometimes used as a source of dye. The tree is also used in agroforestry, as it is known to improve soil fertility and can support sustainable farming practices. The tree has gained attention as a potential bioenergy crop, as its leaves and branches can be used as a source of biomass energy.
Light Requirements
Harungana robynsii Spirlet prefers full sun to partial shade. It thrives in areas with bright light but can tolerate some shading from surrounding plants or structures.
Temperature Requirements
The ideal temperature range for Harungana robynsii Spirlet growth is between 20°C to 30°C. It is a tropical plant that will not survive in temperatures below 15°C. The plant can withstand seasonal changes and mild frosts, but it's best to keep the temperature above 15°C for optimal growth.
Soil Requirements
The plant prefers well-drained soil that is moist but not waterlogged. Harungana robynsii Spirlet thrives on soils with a pH range between 6 and 8. The plant can grow in various soils, including sandy and clayey soils. It is essential to ensure that the soil is enriched with organic matter and has good drainage to prevent waterlogging.
Cultivation of Harungana robynsii Spirlet
Harungana robynsii Spirlet is a fast-growing, woody plant that can be propagated either by seed or by cuttings. It prefers well-drained soil and can grow in a range of soils, from sandy loam to heavy clay.
Propagation by cuttings is the most effective way to ensure the characteristics of the parent plant are retained. Prepare cuttings by cutting a length of stem approximately 10cm long and removing leaves from the bottom 5cm. Dip the cutting in a rooting hormone and plant in well-drained soil. Water the cutting regularly to keep it moist until it has rooted.
Watering Needs of Harungana robynsii Spirlet
Harungana robynsii Spirlet requires regular watering, especially during the dry season. Watering should be done early in the morning or late in the afternoon and should be directed at the base of the plant to avoid wetting the leaves, which can encourage fungal growth.
It is important not to overwater the plant as this can lead to root rot. To avoid overwatering, allow the top layer of soil to dry out slightly before watering the plant again.
Fertilization of Harungana robynsii Spirlet
Harungana robynsii Spirlet prefers a balanced fertilizer containing nitrogen, phosphorus and potassium, applied during the growing season. Fertilizer should be applied to the soil around the base of the plant and lightly watered in.
Over-fertilizing can lead to the plant producing too much foliage and not enough flowers or fruits. It is essential to follow the manufacturer's instructions when applying fertilizer to avoid overfeeding the plant.
Pruning of Harungana robynsii Spirlet
Pruning of Harungana robynsii Spirlet should be done during the dry season. The plant benefits from regular pruning to promote bushiness and a more compact growth habit. Additionally, the removal of dead or damaged branches can help to prolong the life of the plant and keep it looking healthy.
Pruning should be done with clean, sharp tools, and the cut should be made just above a leaf node. It is important not to prune too much foliage at once as this can stress the plant and inhibit its growth.
Propagation of Harungana robynsii Spirlet
Harungana robynsii Spirlet can be propagated by several methods that include:
Seed Propagation
The seeds of Harungana robynsii Spirlet are collected from its fruits, which are oblong, smooth-skinned, and contain 1-2 seeds. The seeds are cleaned, dried, and stored in a cool and dry place before sowing. The sowing is usually done during the rainy season to ensure proper germination and growth of the seedlings.
Before sowing, the seeds are soaked in water for 24 hours to break their dormancy. The sowing of the seeds is done in containers or seedbeds filled with fertile soil. The seeds are covered with a thin layer of soil and kept moist by regular waterings. The seedlings usually emerge after 15-20 days, and they are transplanted to individual containers or field sites after they attain sufficient height and vigor.
Cuttings
Cuttings are also used to propagate Harungana robynsii Spirlet. Stem cuttings of 10-15 cm length are collected from mature and healthy plants during the rainy season. The cuttings are treated with rooting hormones like IBA or NAA to enhance their rooting ability.
The cuttings are planted in containers or raised beds filled with a mixture of sand and peat moss. The soil mixture is kept moist by regular waterings and covered with a polythene sheet to maintain high humidity. The cuttings usually root within 2-3 weeks, and they are transplanted to individual containers or field sites after they attain sufficient height and vigor.
Air Layering
Air layering is another method used to propagate Harungana robynsii Spirlet. A section of the stem of the plant is selected for air layering, and its bark is removed to expose the cambium layer. The exposed area is treated with rooting hormones and covered with a moist sphagnum moss and polythene sheet.
The covered area is kept moist by regular waterings, and roots develop from the exposed cambium layer within 2-3 weeks. After sufficient root development, the air-layered section is cut and planted in individual containers or field sites filled with fertile soil.
Disease and Pest Management for Harungana robynsii Spirlet
Harungana robynsii Spirlet is a hardy plant that is not particularly prone to diseases or pests. However, like all living organisms, it is not immune to these problems and may suffer from them occasionally. Here are some common diseases and pests that might affect the plant and suggestions on how to manage them:
Diseases
Powdery mildew: Powdery mildew is one of the most common plant diseases and can affect Harungana robynsii Spirlet. The disease manifests itself as a white, powdery coating on the leaves, stems, and flowers of the plant. To manage this disease, ensure that the plant is well-ventilated, avoid overcrowding of plants, water early in the morning to allow leaves to dry off during the day, and remove and destroy infected plant parts.
Leaf spots: Leaf spots are another common disease that can affect H. robynsii Spirlet. The disease appears as circular, brown spots with yellow halos on the plant's leaves. To manage this disease, prune and remove infected plant parts, avoid overhead watering, and prevent plant overcrowding.
Pests
Spider mites: Spider mites are tiny pests that can damage H. robynsii Spirlet by sucking on its sap, causing yellowing and dryness of the leaves. To manage spider mites, spray the plant with a direct stream of water to wash away the pests, introduce beneficial insects like ladybugs that prey on spider mites, and apply insecticidal soap.
Caterpillars: Caterpillars can also attack Harungana robynsii Spirlet and cause defoliation. To manage this pest, handpick and remove caterpillars from the plant, apply insecticidal soap, and introduce beneficial insects like parasitic wasps that prey on caterpillars.
By following these disease and pest management tips, you can keep your Harungana robynsii Spirlet plant healthy and thriving.
