Overview
Voandzeia subterranea (L.) DC. forma spontanea Harms, commonly known as Bambara groundnut or Bambara nut, is a tropical legume originally from sub-Saharan Africa. It is a drought-resistant and hardy crop, adapted to grow in diverse soil conditions. The plant has gained attention as a promising food and nutritional source in many African and Asian countries owing to its rich nutrient profile and easy cultivation.
General Appearance
The plant is a short-lived annual herb that grows up to 20-60 cm in height. It has a well-developed taproot that can penetrate into the soil up to 2 meters deep. The leaves are trifoliate and alternate, with ovate leaflets that are 2-7 cm long and covered in dense hair. The flowers are small and papilionaceous, with pink, bluish or lilac corolla, and yellowish-white or green sepals. The fruits are small, round, and hard-shelled pods that contain 1-3 seeds each. The seeds are the edible part of the plant, which are oval or ellipsoid in shape, measuring 1-2 cm long and 1-1.5 cm wide.
Common Names
The plant is commonly known as Bambara groundnut or Bambara nut, deriving its name from the Bambara-speaking people of West Africa who cultivate and consume it as a staple food. It is also known by other local names such as earth pea, guber bean, congo goober, and njugumawe in different parts of Africa.
Uses
The Bambara nut is a nutritious and versatile crop that can be used in multiple ways. It is a rich source of protein, fiber, amino acids, vitamins, and minerals, providing a well-balanced diet for humans and livestock. The nut is consumed boiled, roasted, fried, or ground into flour, and used in various culinary preparations such as porridge, soup, sauce, snacks, and cakes. The nut is also used in traditional medicine for treating various ailments such as diarrhea, diabetes, and hypertension. The crop is of great economic value, being an important source of income for farmers and traders.
In conclusion, Voandzeia subterranea (L.) DC. forma spontanea Harms, commonly known as Bambara groundnut or Bambara nut, is a promising and valuable crop in many African and Asian countries. Its easy cultivation, adaptability to diverse soil and climatic conditions, rich nutrient profile, and multiple uses make it a recommended crop for food security and sustainable agriculture.Light Requirements
Voandzeia subterranea is a moderately shade-tolerant plant, and as such, it prefers to grow under partial shade. It can tolerate full sun, but this may cause the leaves to scorch and dry out. Therefore, it is recommended to grow Voandzeia subterranea in areas with 30-75% shade level.
Temperature Requirements
Voandzeia subterranea grows best in warm temperatures, thriving in the range of 25-35°C. At temperatures below 20°C, the growth rate of the plant slows down. At temperatures above 40°C, the plant may experience heat stress, resulting in many leaflets and stunted growth. In areas that experience cold weather, it is recommended to plant Voandzeia subterranea in a greenhouse or indoors to provide the optimal temperature.
Soil Requirements
Voandzeia subterranea can grow in various soil types, including sandy loam, clay loam, and lateritic soils, but it prefers well-drained soils. The ideal soil pH for Voandzeia subterranea growth ranges from 5.5 to 7.5; therefore, it is essential to ensure the soil pH is within this range. The plant requires moderate soil fertility, and it is recommended to add some compost or organic matter to improve soil structure and fertility. In areas with poor soil quality, it is advisable to grow Voandzeia subterranea in raised beds or containers filled with suitable soil mixes.
Cultivation Methods
Voandzeia subterranea (L.) DC. forma spontanea Harms is a tropical plant that prefers warm, humid conditions. It is commonly grown as an annual crop that reaches maturity within 70 to 100 days. The plant grows best in well-drained, sandy soil that is rich in organic matter. It is tolerant of drought conditions, but too much moisture can cause root rot.
The seeds of the plant should be sown directly into the soil in rows that are spaced about 50 cm apart. The seeds should be covered with about 2-3 cm of soil. It is important to maintain adequate soil moisture during the germination period to ensure good seedling emergence.
Watering Needs
Voandzeia subterranea (L.) DC. forma spontanea Harms requires regular watering to maintain adequate soil moisture for optimal growth. The plant should be irrigated about two to three times per week, depending on the weather conditions. Overwatering can lead to root rot, while underwatering can cause stunted growth and lower yields.
Fertilization
The plant requires a balanced fertilizer specifically formulated for legumes. A nitrogen-rich fertilizer can encourage vegetative growth at the expense of fruit formation, resulting in low yields. Fertilizing the plant about four weeks after planting can help promote healthy growth and better yields. It is important to follow the fertilizer application instructions carefully to avoid burning the plant's roots.
Pruning
Pruning is not usually necessary for Voandzeia subterranea (L.) DC. forma spontanea Harms because it typically grows as a bush that doesn't require training. However, pruning can be done to remove dead or damaged plant parts to promote new growth. Pruning should be done during the early vegetative stage to avoid damaging the plant's growth.
Propagation of Voandzeia subterranea (L.) DC. forma spontanea Harms
Voandzeia subterranea (L.) DC. forma spontanea Harms, commonly called Bambara groundnut, is an important legume crop in the African continent. It is a warm-season crop that is predominantly propagated through seed.
Seed propagation
In the case of Bambara groundnut, seed propagation is the most common method of propagation. The seeds are either directly sown into the field or raised in a nursery before transplanting them. In the nursery technique, the seeds are sown in seed trays or polybags filled with soil, and the seedlings are transplanted into the field at the appropriate time. Direct sowing, on the other hand, involves broadcasting the seeds onto a well-prepared field and covering them lightly with soil.
Vegetative propagation
Bambara groundnut can also be propagated vegetatively using various methods such as stem cuttings, root cuttings, and layering. However, these methods have limited success rates and are not commonly used.
In vitro propagation
In vitro propagation techniques, such as tissue culture, have been advanced as a potential alternative to conventional propagation methods. It involves the use of plant tissue culture techniques to produce large quantities of healthy and uniform plantlets from a small amount of plant tissue. Tissue culture propagation provides an excellent means of maintaining Bambara groundnut genetic resources and producing large-scale clonal propagation of elite cultivars.
Disease and Pest Management for Voandzeia subterranea (L.) DC. forma spontanea Harms
Voandzeia subterranea, also known as Bambara groundnut, is a legume crop widely cultivated in Africa. As with other crops, it is vulnerable to various diseases and pests. Effective disease and pest management will help to ensure healthy plants and optimal yield.
Common Diseases
The most common diseases that affect Bambara groundnut are fungus-based, particularly Fusarium and Rhizoctonia. Fusarium wilt infects the plant through the roots and colonizes the vascular tissue, causing leaf yellowing, wilting, and eventually plant death. Rhizoctonia solani infects the stem base, causing damping-off in seedlings, root rot, and collar rot in older plants.
To manage Fusarium and Rhizoctonia, use disease-free seedlings, rotate crops every few years, and practice good soil management. You can also use fungicides, such as copper-based formulations, to prevent and control disease spread.
Common Pests
The major pests affecting Bambara groundnut are aphids and thrips. Aphids feed on the plant sap, causing leaf curling, wilting, and stunted growth. Thrips damage plants by feeding on young leaves, flowers, and pods, causing leaf drop, browning, and deformed pods.
To manage pests, maintain good crop hygiene, including routine weeding and removal of plant debris. Biological pest control using predators such as ladybirds and lacewings can also be effective. You can also use insecticides, such as neem oil, to control pest populations. However, it is important to use these products in moderation and follow instructions carefully to avoid harming beneficial organisms and inducing insecticide resistance.
Conclusion
Effective disease and pest management for Voandzeia subterranea is essential for ensuring optimal yield and healthy plants. Regular monitoring of plant health is vital, and prompt action should be taken if any disease or pest infestation is detected. By implementing good management practices and appropriate chemical or biological control strategies, it is possible to mitigate the impact of disease and pests on Bambara groundnut and maintain healthy plants and optimal yield.
