Origin and Common Names
Macrolobium explicans, also known as "pau d'óleo" or "sororoca" in Brazil, is a flowering tree species belonging to the family Fabaceae. It is native to the Amazon rainforest and can be found in Brazil, Colombia, and Peru.Appearance
The Macrolobium explicans tree can grow up to 30 meters tall and has a dense, rounded crown. Its bark is dark brown and deeply furrowed, giving it a distinctive appearance. The leaves are compound and can reach up to 30 centimeters in length, with each leaflet being about 5 to 7 centimeters in length. The tree produces small, greenish-white flowers that are approximately 1.5 centimeters in diameter.Uses
The wood of Macrolobium explicans is highly valued in the timber industry for its strength and durability, making it ideal for constructing heavy-duty utility poles, railway ties, and flooring. Additionally, the oil extracted from its seeds is used as a lubricant in machinery and as a fuel for lamps. The indigenous peoples of the Amazon also use the tree's bark and roots for medicinal purposes, often as an antipyretic, analgesic, and anti-inflammatory agent.Growth Conditions of Macrolobium Explicans
Macrolobium Explicans is a leguminous plant native to tropical Africa that typically grows into a small shrub or tree. This plant can tolerate a wide range of growth conditions but thrives in specific environmental settings. Here are some of the typical growth conditions required for the plant:
Light
Macrolobium Explicans prefers partial shade to full sunlight for optimal growth. However, too much shade can limit its growth due to reduced photosynthesis while too much sunlight can lead to leaf scorch. The plant requires about 50-70% shade cover but can still thrive up to 30% shade coverage. In areas with intense sunlight, artificial shade may be necessary to protect the plant from excessive radiation.
Temperature
Macrolobium Explicans requires a warm and humid environment to grow well. The plant prefers temperatures ranging between 20°C and 35°C, and average humidity above 60%. Extreme temperature changes may cause the plant to drop leaves or even die. Freezing temperatures are especially harmful to young plants and should be avoided. In colder regions, growing Macrolobium Explicans in greenhouses is recommended.
Soil Requirements
The plant grows best in well-draining soils, rich in organic matter and nutrients. Macrolobium Explicans prefers slightly acidic to neutral soils with a pH range of 5.5 to 7. The soil must be properly aerated to promote root growth, and waterlogged soils should be avoided as they lead to root rot. Adding organic matter such as compost is beneficial in improving soil fertility and structure.
Overall, providing the right balance of light, temperature, and soil moisture is key in cultivating healthy Macrolobium Explicans plants. With proper care, the plant can thrive and provide multiple benefits, including improving soil fertility and providing shade for other crops.
Cultivation
Macrolobium explicans is a tropical plant that thrives in warm and humid conditions. It grows well in loamy soil that is rich in organic matter. The plant prefers a spot with partial shade and protection from strong winds. It can be propagated through seeds, and the ideal time for planting is during the rainy season.
Watering Needs
Macrolobium explicans requires regular watering to keep its soil moist. However, it is essential to avoid overwatering, especially during the colder months, as this can cause root rot. The frequency of watering will depend on the prevailing weather conditions and the type of soil in which the plant is grown. If the soil is sandy, watering may need to be more frequent compared to plants grown in a loamy soil.
Fertilization
For Macrolobium explicans to grow and thrive, it requires regular fertilization. Farmers who grow this plant commercially use a balanced fertilizer with equal proportions of nitrogen, phosphorous, and potassium. It is advisable to feed the plant every three months, especially during the growth period. Ensure that you follow the application instructions indicated on the fertilizer package.
Pruning
Pruning of Macrolobium explicans is essential to maintain its shape and promote healthy growth. Pruning should be done after the plant sheds its leaves, and the ideal time is during the dry season. Cut back any overgrown branches, dead or diseased branches, and any branches that are rubbing against each other. Pruning will also encourage the plant to produce more branches, which can enhance its aesthetic value.
Propagation of Macrolobium explicans (Baill.) Keay
Macrolobium explicans (Baill.) Keay is a plant native to West Africa and belongs to the Fabaceae family. It is commonly known as "Opepe" or "Ironwood" and is used for timber and wood carving. Propagation of this tree species can be done through several methods, including seeds, cuttings, and air layering.
Propagation by Seeds
Seeds are the easiest method for propagating Macrolobium explicans. The seeds should be collected from healthy, mature trees during the fruiting season. The collected seeds should be sun-dried for a few days, and their wings should be removed. The seeds can then be stored in a cool, dry place for later use. To germinate the seeds, they should be soaked in lukewarm water for 24 hours and sown in planting bags filled with a mixture of soil and manure. The seedlings can be transplanted to the field after six months.
Propagation by Cuttings
Propagation by cuttings is another method for Macrolobium explicans. Cuttings are usually made from young shoots or roots. The cuttings should be about 15-20 centimeters long and should have at least four nodes. The lower nodes of the cutting should be treated with rooting hormone powder before planting in a rooting medium. After about six weeks, the cuttings should have developed roots and can be transplanted to the field.
Propagation by Air Layering
Air layering is a propagation method that involves wounding and ringing a branch of a plant to encourage root formation. To propagate Macrolobium explicans through air layering, select a healthy branch and remove a ring of bark about 2 centimeters wide. The wound should be treated with rooting hormone powder and wrapped with moist sphagnum moss. The moss should then be wrapped with polythene paper and tied firmly. After about two months, the roots should have formed, and the new plant can be cut off from the parent and planted in a pot or directly in the field.
Disease Management for Macrolobium explicans
Macrolobium explicans is generally a healthy plant with very few reported cases of diseases; however, following are some of the common diseases that might affect this plant:
- Root Rot: This is the most common disease affecting Macrolobium explicans. It is caused by soil-borne fungi like Fusarium oxysporum, Pythium spp. and Rhizoctonia solani. The diseased plant shows yellowing of leaves and eventually wilting. To manage this disease, remove infected plants from the field and avoid excessive watering.
- Leaf Spot: Leaf spot disease is caused by the Phyllosticta fungus. Infected leaves have small necrotic spots with a yellow halo around them. To manage this disease, remove the infected leaves and spray the plant with a copper-based fungicide.
- Anthracnose: It is caused by Colletotrichum gloeosporioides, which leads to necrotic spots on the leaves and fruits. To manage this disease, remove the infected parts and spray the plant with a copper-based fungicide.
Pest Management for Macrolobium explicans
Macrolobium explicans is also prone to insect pests that might affect its growth and yield. Following are some of the common pests that affect this plant:
- Bean fly: The bean fly is a major pest of Macrolobium explicans. Larvae of the bean fly feed on the plant roots, leading to stunted growth and yellowing of the leaves. To manage this pest, remove the infected plants from the field and use crop rotation.
- Mealybugs: Mealybugs are small sucking insects that cause yellowing and wilting of the plant. To manage this pest, use insecticidal soap or neem oil spray.
- Leafminer: The leafminer is a harmful pest that feeds on the leaves of the plant, leading to yellowing and stunted growth. To control this pest, prune the infected leaves or use a pesticide recommended by your local agricultural university.
