Origin
Vigna unguiculata (L.) Walp. var. huillensis (Welw. ex Baker) B.J.Pienaar is a subspecies of the Vigna unguiculata (cowpea) native to Angola. It is commonly found in the southern regions of the country, particularly in the Huila province.
Common Names
Also known as the Angolan cowpea or Huila cowpea, Vigna unguiculata var. huillensis is primarily referred to by its scientific name in botanical circles. However, it is also called "frijol de Angola" in some Spanish-speaking countries, which translates to "bean of Angola".
Uses
Vigna unguiculata var. huillensis is an important staple food in Angola, particularly in the southern regions where it is most commonly found. The cowpea is a versatile crop that can be used in a variety of dishes, ranging from stews to soups and even fried snacks. It is high in protein, fiber, and essential vitamins and minerals, making it an ideal addition to a healthy and balanced diet. Additionally, the cowpea plant is highly valued for its nitrogen-fixing properties, which make it an important crop in crop rotation systems.
General Appearance
The Vigna unguiculata var. huillensis plant is a sprawling, herbaceous annual with slender stems that can grow up to 2 meters in length. The leaves are alternate and trifoliate, with ovate leaflets that are about 2-8 cm long and 1-6 cm wide. The flowers are small and white or cream-colored, with prominent purple or dark brown markings on the keel. The fruit is a pod that is about 10-20 cm long and contains 10-15 seeds, which are small and round with a beige to light brown coloration.
Light Requirements
Vigna unguiculata var. huillensis grows best in full sunlight to partial shade conditions. It can tolerate some shade, but extended periods of little to no sunlight can result in stunted growth and reduced yields.
Temperature Requirements
This variety of Vigna unguiculata prefers warm to hot temperatures ranging from around 77-95°F (25-35°C). It is not frost tolerant and does not thrive in cooler climates. In regions with cooler temperatures, it can be grown as an annual plant.
Soil Requirements
Vigna unguiculata var. huillensis grows best in well-draining soils with a pH ranging between 6.0-7.5. It can tolerate a range of soil textures from sandy to clay soils, but it prefers loamy soils. The plant is also able to grow in soils with low to moderate fertility; however, adding compost and other organic matter can greatly improve the quality of the growth medium.
Cultivation Methods for Vigna unguiculata var. huillensis
Vigna unguiculata var. huillensis, commonly known as cowpea, prefers tropical climates with temperatures between 25°C to 35°C. It is best grown in well-drained sandy loam soils with a pH range of 6.0 to 7.5. The plant has a high tolerance for drought, making it suitable for cultivation in areas with low rainfall. The seeds of Vigna unguiculata var. huillensis can be directly sown into the soil or transplanted as seedlings.
Watering Needs for Vigna unguiculata var. huillensis
Watering plays a crucial role in the growth and development of cowpea. The plant requires regular watering during the flowering and podding stages. It is advisable to water the plant early in the morning or late in the evening to reduce evaporation. Overwatering can lead to root rot, while underwatering can cause the plant to wilt. The soil should be moist but not waterlogged.
Fertilization of Vigna unguiculata var. huillensis
Vigna unguiculata var. huillensis responds well to fertilization. It is recommended to apply a balanced fertilizer with an N-P-K ratio of 20:10:10 at planting. Nitrogen is critical for the growth and development of the plant, so it is advisable to apply a nitrogen-based fertilizer at the onset of flowering. Organic fertilizers like manure and compost are also suitable for promoting growth and increasing yields.
Pruning of Vigna unguiculata var. huillensis
Pruning is not necessary for cowpea, as it is a low-growing plant that does not require support. However, it is advisable to remove dead or damaged leaves to prevent the spread of diseases. The removal of old pods may also encourage the development of new pods, leading to increased yields.
Propagation of Vigna unguiculata (L.) Walp. var. huillensis (Welw. ex Baker) B.J.Pienaar
Vigna unguiculata (L.) Walp. var. huillensis (Welw. ex Baker) B.J.Pienaar, commonly known as cowpea, is propagated through sexual and asexual methods.
Sexual propagation
The plant produces seeds that can be used for propagation. The seeds should be collected from healthy plants when they are fully matured.
Cowpea can be planted in the field directly as it is a hardy plant that can grow in adverse conditions. However, it is important to choose a well-drained soil that is rich in organic matter.
The seeds should be planted about 3-5 cm deep in the soil and spaced about 10-15 cm apart from each other.
The best time to plant cowpea is during the rainy season when there is sufficient moisture in the soil.
Asexual propagation
Cowpea can also be propagated asexually through stem cuttings and grafting.
For stem cuttings, select a healthy plant and cut a stem that is about 15-20 cm long. Remove the leaves from the lower part of the stem and dip it in rooting hormone powder.
Plant the stem cutting in a pot filled with well-draining potting soil and keep it in a shaded area. The cutting should develop roots within 2-3 weeks.
Grafting can also be used for propagation, especially for improving the quality of the plant.
The scion of a desirable plant is grafted onto the rootstock of a vigorous cowpea plant. The graft union is then covered with a grafting tape to prevent moisture loss and infection.
The grafted plant should be kept in a humid environment until it establishes new roots.
Both sexual and asexual propagation methods can be used to propagate Vigna unguiculata (L.) Walp. var. huillensis (Welw. ex Baker) B.J.Pienaar. The choice of method to use will depend on the grower's preference and the purpose of propagation.
Disease and Pest Management for Vigna unguiculata var. huillensis
Vigna unguiculata var. huillensis, commonly known as cowpea, is a hardy plant with few pest and disease problems. However, like any plant, it is still susceptible to various pests and diseases that can cause significant damage if not managed correctly. Here are some of the most common diseases and pests that affect cowpeas and how to manage them:
1. Cowpea Aphid
The cowpea aphid is a small, soft-bodied insect that feeds on the sap of the cowpea plant. Infested plants show stunt growth, yellowing, and wilting leaves. Cowpea aphids can also transmit viruses, which can cause severe plant damage. To manage cowpea aphids, you can introduce natural predators like ladybugs and lacewings or use insecticidal soap or neem oil.
2. Cowpea Weevil
The cowpea weevil is a common pest of cowpeas. These insects lay their eggs in immature cowpea pods, and once hatched, the larvae feed on the developing seeds. The damage caused by cowpea weevils can result in reduced yields. To manage cowpea weevils, ensure that the seeds are stored in a cool and dry place or treated with insecticides or natural repellents like diatomaceous earth.
3. Anthracnose
Anthracnose is a fungal disease that causes circular, sunken lesions on the leaves and stems of cowpea plants. The disease can spread quickly in warm and moist conditions. To manage anthracnose, ensure that you space the plants correctly to improve air circulation, remove and destroy infected plants, and apply fungicides as a last resort.
4. Bacterial Blight
Bacterial blight is a bacterial disease that affects the stems, leaves, and pods of cowpea plants. Infected plants develop water-soaked lesions that turn brown and necrotic over time. The bacteria spread through rain splash, irrigation water, and farm implements. To manage bacterial blight, you can remove and destroy infected plants, avoid overhead irrigation, and apply copper-based fungicides.
In conclusion, managing diseases and pests in Vigna unguiculata var. huillensis is essential to ensure good yields and plant health. By implementing the above measures, you can prevent and manage common pests and diseases that affect cowpeas.
