Origin
Vigna unguiculata (L.) Walp. var. pubescens (R.Wilczek) Maréchal & Mascherpa & Stainier, commonly known as the hairy cowpea, is a subspecies of the cowpea plant, which is native to Africa. The plant is widely cultivated in tropical and sub-tropical regions of Africa, Asia, and Latin America.
Common Names
The plant is known by various names in different regions. In West Africa, it is commonly called "niebe" or "black-eyed beans." In other regions, it is known as "southern pea," "crowder pea," "yard-long bean," "poor man's meat," and "cowpea."
Uses
The hairy cowpea is highly valued for its nutritional value and versatility in cooking. The plant is a good source of protein, dietary fiber, vitamins, and minerals. Its young pods, leaves, and seeds are all edible and used in a wide range of dishes, such as stews, soups, salads, and porridge. The seeds are also commonly used for sprouting, making flour, and fermenting to produce beverages.
General Appearance
The hairy cowpea is a climbing or trailing vine that can grow up to 2 meters in length. The plant has hairy stems, leaves, and pods. Its leaves are trifoliate, meaning it has three leaflets that are ovate and pointed. The flowers are white or cream-colored and grow in clusters on a long stalk. The pods are elongated and have a curved shape, with a hairy surface. The seeds are kidney-shaped, cream-colored, and have a distinctive black "eye" or hilum on one end.
Light Requirements
Vigna unguiculata (L.) Walp. var. pubescens (R.Wilczek) Maréchal & Mascherpa & Stainier prefers full sunlight, as it is a crop species adapted to grow in tropical and subtropical regions. Therefore, it requires a minimum of 6-8 hours of direct sunlight per day for optimal growth and development.
Temperature Requirements
As a tropical crop, Vigna unguiculata (L.) Walp. var. pubescens (R.Wilczek) Maréchal & Mascherpa & Stainier requires warm temperatures to thrive. It is recommended to plant the crop when the soil temperature is at least 18°C and the air temperature is consistently above 21°C. The optimal temperature range for growth and development is between 25-35°C during the day and 22-30°C at night.
Soil Requirements
Vigna unguiculata (L.) Walp. var. pubescens (R.Wilczek) Maréchal & Mascherpa & Stainier prefers well-draining soils. The soil should have a pH of 6.0-7.0 and be rich in organic matter. Sandy loam soils are preferred because they allow good drainage and airflow, prevent waterlogging, and increase root penetration. This variety of cowpea can tolerate a wide range of soil types, including sandy, loamy, and clay soils with proper drainage.
Cultivation Methods
Vigna unguiculata (L.) Walp. var. pubescens (R.Wilczek) Maréchal & Mascherpa & Stainier, commonly known as cowpea or southern pea, is a warm-season crop that grows best in full sun and well-drained soil. It requires a minimum of 120 frost-free days to mature, and its seeds can be sown directly into the ground or started indoors and transplanted.
When planting directly into the ground, sow the seeds after all danger of frost has passed and the soil has warmed up to at least 60°F. Seeds should be planted at a depth of 1-2 inches and spaced 2-4 inches apart. Rows should be spaced 3-4 feet apart.
If starting indoors, sow the seeds in peat pots or other biodegradable containers 4-6 weeks before the last frost. Before transplanting, harden off the seedlings by gradually exposing them to outdoor conditions over the course of a week or two.
Watering Needs
Cowpea plants require moderate watering, with the soil kept consistently moist but not waterlogged. In general, they require 1-2 inches of water per week. During periods of drought, it may be necessary to water more frequently or use irrigation.
When watering, it's best to apply water directly to the soil rather than the leaves, as wet foliage can increase the risk of disease. Water early in the day to allow leaves to dry before nightfall.
Fertilization
Cowpea plants prefer soil that is moderately fertile and well-draining. Prior to planting, it's recommended to amend the soil with organic matter, such as compost or well-rotted manure.
During the growing season, additional fertilizer may be applied as needed. A balanced fertilizer with equal amounts of nitrogen, phosphorus, and potassium is recommended. In general, avoid over-fertilizing, as this can lead to excessive vegetative growth and reduced yields.
Pruning
Cowpea plants generally don't require pruning. However, it's a good idea to remove any diseased or damaged foliage or pods as soon as they're noticed to prevent the spread of disease. To encourage branching and a bushier growth habit, you can pinch off the tips of the main stems once the plants reach a height of 8-10 inches.
Propagation of Vigna unguiculata var. pubescens
Vigna unguiculata var. pubescens is commonly propagated by seed. However, propagation by stem cuttings is also possible. Here are the two main propagation methods:
Propagation by Seed
Vigna unguiculata var. pubescens can be easily propagated by seed. The seeds are small and can be directly sown into the soil. The following steps can be followed for propagation by seed:
- Collect mature pods from the parent plant.
- Shell the pods to obtain the seeds.
- Clean the seeds and soak them in water for 12 to 24 hours.
- Sow the seeds in a seed tray or directly in the soil. Sow the seeds 2 cm deep and 5 to 10 cm apart.
- Water the seeds regularly, keeping the soil moist but not waterlogged.
- The seeds will germinate within 5 to 10 days.
- Once the seedlings have 2 to 4 true leaves, transplant them to their final location.
- Water the transplanted seedlings regularly until they are established.
Propagation by Stem Cuttings
Vigna unguiculata var. pubescens can also be propagated by stem cuttings. The following steps can be followed for propagation by stem cuttings:
- Select healthy stems that are 5 to 10 cm long and have 2 to 3 nodes.
- Cut the stems from the parent plant just below a node.
- Remove the lower leaves from the stem, leaving only the top two leaves.
- Dip the cut end of the stem in rooting hormone powder.
- Plant the stem in a pot filled with a mixture of sand and peat moss in equal parts.
- Water the cutting immediately and place it in a shaded area.
- Mist the cutting with water twice a day to keep the soil moist.
- Roots should appear within 2 to 3 weeks.
- Once the cutting has established roots, transplant it to its final location.
Disease management
Common diseases affecting Vigna unguiculata (L.) Walp. var. pubescens (R.Wilczek) Maréchal & Mascherpa & Stainier include:
- Anthracnose: This disease is caused by the fungus Colletotrichum capsici and can affect leaves, stems, and pods. Symptoms include small, sunken lesions with tan centers and dark, reddish-brown borders. Control measures include removing infected plant debris, planting resistant varieties, and using fungicides.
- Rust: Rust is caused by several fungal species and can affect leaves, stems, and pods. Symptoms include orange to brown raised pustules on the undersides of leaves. Control measures include removing infected plant debris, providing adequate air circulation, and using fungicides.
- Mosaic viruses: Several virus species can cause mosaic symptoms on Vigna unguiculata (L.) Walp. var. pubescens, including cowpea mosaic virus and bean common mosaic virus. Symptoms include yellow mottling on leaves and stunted growth. Control measures include planting virus-resistant varieties and controlling insect vectors.
Pest management
Common pests affecting Vigna unguiculata (L.) Walp. var. pubescens include:
- Aphids: These small, soft-bodied insects feed on the sap of plants and can transmit viruses. Control measures include removing infested plant parts, using insecticidal soap or oil, and attracting natural enemies such as ladybugs.
- Spider mites: These tiny pests can cause yellow stippling on leaves and produce fine webbing. Control measures include removing infested plant parts, providing adequate moisture, and using miticides.
- Cutworms: The larvae of various moth species can cut through the stems of young plants. Control measures include using physical barriers such as collars around the plants, using biological controls such as parasitic nematodes, and using insecticides.
