Overview: Plukenetia conophora Müll.Arg.
Plukenetia conophora Müll.Arg. also known as the Nigerian walnut or Tetracarpidium conophorum (Müll.Arg) Hutch. & Dalziel is a plant that belongs to the family Euphorbiaceae. It is native to tropical West Africa and is widely used in African traditional medicine because of its medicinal properties. The plant is a source of edible oil, protein, and other micro and macronutrients.
Appearance
Plukenetia conophora is a small to medium-sized tree that can grow up to 20 meters tall with a trunk diameter of 60 centimeters. The tree has a straight, grayish-brown bark with horizontal fissures, and a round crown. The leaves are simple, alternate, and have a palmate appearance. The tree produces small, yellowish-green flowers that are followed by a fruit which is a flat, rounded capsule containing up to four seeds.
Common Names
The plant is commonly known as Nigerian walnut in English, and Okhue or Ukpa in the Edo language of Nigeria. In other regions, it is called Aju mbaise in the Igbo language, Oriyo in the Tiv language, Ikpaba in the Esan language, and Nangbah in the Bassa language of Cameroon.
Uses
Plukenetia conophora has several uses. The seeds of the plant are a rich source of protein, carbohydrates, and essential fatty acids such as omega-3, 6, and 9. The oil extracted from the seeds is used for cooking, lighting, and as a skin moisturizer. The plant has also been used in traditional medicine to treat various ailments such as malaria, diarrhea, wounds, and respiratory problems. The leaves and bark of the tree have antibacterial and antifungal properties, and they are used in preparing traditional herbal remedies. The wood of the tree is used in making furniture and household items, and it is locally referred to as Nangbah wood.
In conclusion, Plukenetia conophora is a versatile plant with various uses. Its oil and protein-rich seeds, as well as its medicinal properties, make it an essential plant in West African traditional medicine and socio-economy.
Light Requirements
Plukenetia conophora prefers full sun to partial shade for optimal growth. It requires at least 6 hours of direct sunlight daily. Insufficient light can result in slower growth, weaker stems, and reduced yield.
Temperature Requirements
The plant grows well in both tropical and subtropical regions. It grows best under warm temperatures between 20°C and 30°C. Temperatures above 35°C may cause heat stress and reduce productivity. The plant is susceptible to frost and cannot tolerate temperatures below 10°C.
Soil Requirements
The plant grows well in well-draining sandy loam soil with a pH range of 5.5 to 7.5. The soil must be rich in nutrients, especially nitrogen, phosphorus and potassium. The plant performs poorly in heavy clay soils. The soil should be moist but not waterlogged. Overwatering the plant may lead to root rot.
Cultivation of Plukenetia conophora Müll.Arg.
Plukenetia conophora Müll.Arg., commonly known as Sacha inchi, is a plant species indigenous to South America. The following are some of the most useful hints for growing it:
- Plukenetia conophora grows best in tropical climates with a temperature range of 20-30°C.
- The plant thrives in well-draining, nutrient-rich soil with a slightly acidic pH level of between 5.5 and 6.5.
- The soil should also be kept slightly moist and aerated for best results.
- Sacha inchi can be propagated using its seeds, which should be sown in seedbeds or polybags for about 2-3 months before transplanting.
- When transplanting, the seedlings should be protected from direct sunlight and strong winds for a few days to allow them to adjust to their new environment.
Watering Needs of Plukenetia conophora Müll.Arg.
Like any other plant, Sacha inchi requires consistent moisture in order to thrive, particularly during the growing season:
- Water Sacha inchi plants once a week during periods of drought, with enough water to moisten the entire root area.
- Adequate drainage is essential to prevent waterlogging, which can result in root rot and plant death.
- During moist weather conditions, it is necessary to limit watering to prevent the plant from drowning.
- Moreover, the leaves should be misted with water from time to time to promote humidity around the plant.
Fertilization of Plukenetia conophora Müll.Arg.
Plukenetia conophora requires sufficient nutrients for proper growth and development. Therefore, it is critical to fertilize the plant regularly:
- A nitrogen-rich fertilizer should be applied to the soil once every 4-6 weeks.
- In addition to nitrogen, the plants require phosphorous and potassium to promote healthy growth of stems and leaves.
- Fertilization should be done during the growing season, when the plant is actively putting out new growth.
- Care should be taken to avoid over-fertilizing, as this can burn the plant and cause damage.
Pruning of Plukenetia conophora Müll.Arg.
Pruning is essential in keeping Sacha inchi plants healthy, promoting fruit production, and maintaining their shape:
- Prune the plant occasionally to remove dead or damaged branches, as well as leaves that may be attracting pests.
- Pruning should be done after fruiting to enhance plant development.
- It is important to cut down on overly long branches as they only serve to weaken the plant and reduce its output.
- Apart from improving a plant's visual appeal, pruning can also increase its resistance to pests and diseases by enhancing air circulation.
Propagation of Plukenetia conophora Müll.Arg.
Plukenetia conophora Müll.Arg., commonly known as Sacha inchi, is propagated through both sexual and asexual methods. The plant's propagation is done during the rainy season, which is the ideal time for its growth and development.
Sexual propagation
The seeds of Plukenetia conophora Müll.Arg. are collected from the fruit after it has ripened. The seed is then dried, cleaned, and treated in hot water for a few minutes. The hot water treatment helps to soften the seed coat, which encourages germination.
The seeds can be sown directly into the field, or they can be sown in a nursery for a few weeks to allow for seedling growth before transplanting. The preferred method of sowing is to drill the seed into the field, spacing them at a distance of 50 cm between rows and 30 cm between plants. The seedlings will emerge after one week, and they will take approximately three months to reach maturity.
Asexual propagation
Plukenetia conophora Müll.Arg. can also be propagated through cuttings. The most common method of asexual propagation is through stem cuttings. To obtain cuttings, select healthy and mature branches from the plant that are free from any pests and diseases. The cuttings should be 15 to 20 cm long and have a diameter of 0.5 to 1 cm.
The cuttings should be treated with a rooting hormone to stimulate root growth before planting them in the soil. After planting the cuttings, maintain adequate moisture levels in the soil and protect them from direct sunlight until they properly establish a root system and start growing new leaves.
In conclusion, the propagation of Plukenetia conophora Müll.Arg. through both sexual and asexual methods provides options for farmers to increase the plant's production and maintain its genetic diversity.
Disease and Pest Management for Plukenetia conophora Müll.Arg.
Plukenetia conophora Müll.Arg., commonly known as Sacha Inchi, is a perennial plant native to the Amazon rainforest. It is a highly nutritious plant that is grown for its seeds which are used to produce oil. The plant is vulnerable to a number of diseases and pests that can significantly reduce the yield. Therefore, it is important to manage these diseases and pests through various methods.
Common Diseases
One of the most common diseases that affect Plukenetia conophora is the damping-off disease caused by Sclerotium rolfsii. This fungus infects the seedlings causing them to rot at the soil line and eventually die. To manage this disease, it is important to use clean planting materials, avoid overwatering, and apply fungicides such as carbendazim and metalaxyl.
Another common disease of Plukenetia conophora is anthracnose caused by Colletotrichum gloeosporioides. This disease affects the leaves and stems causing large, dark brown lesions which eventually lead to plant death. To manage this disease, it is important to remove and destroy infected plant parts, avoid overhead irrigation, and apply fungicides such as copper oxychloride and mancozeb.
Common Pests
The most destructive pest of Plukenetia conophora is the sacha inchi weevil (Hypothenemus hampei). The larvae of this beetle bore into the seeds, causing significant damage and reducing the yield. To manage this pest, it is important to harvest the seeds early, before the weevils infest them, and store them properly. Insecticides such as deltamethrin and cypermethrin can also be used.
The leafcutter bee (Megachile sp.) is another pest that can affect Plukenetia conophora. These bees cut circular pieces from the leaves, which can reduce the plant's ability to photosynthesize, leading to reduced yields. To manage this pest, it is important to prune the damaged leaves, use netting to keep the bees off the plants, and plant alternative flowering plants to attract the bees away from the sacha inchi.
In conclusion, Plukenetia conophora is a valuable crop that is vulnerable to a number of diseases and pests. The best way to manage them is through a combination of cultural, biological, and chemical methods. Regular monitoring and early detection are also crucial in managing the diseases and pests.
