Overview
Vigna unguiculata (L.) Walp. is a member of the legume family, native to Africa and widely cultivated throughout the tropics and subtropics.
Common names
The plant is commonly known as cowpea, southern pea, black-eyed pea, crowder pea, lubia or niebe.
Appearance
The cowpea plant is a fast-growing, annual or perennial twining vine, climbing up to 2-4 meters in height, with long branches and pinnate leaves. The leaves are trifoliate, with each leaflet being elliptical or lanceolate, 4-10 cm long, and 2-5 cm wide. The plant produces small, pea-like flowers that range in color from white to yellow to lavender. The fruit is a pod that varies in length from 5 to 20 cm and contains 1 to 15 seeds.
Uses
The cowpea is an important crop for food and animal feed. The seeds are edible and are consumed as a protein-rich food in many parts of the world. They can be cooked fresh, dried, or canned. In addition to being used as a food crop, cowpea is also used as a cover crop, green manure, and forage crop. The plant is highly adaptable and can be grown in a variety of soil types, making it an important crop for areas with limited resources. Cowpea is also known for its medicinal properties, with its extracts being used in the treatment of various ailments such as hypertension, diabetes, and inflammation.
Light Requirements
Vigna unguiculata (L.) Walp. plants require full sunlight exposure to grow well. They do not thrive in shade or partial shade. A minimum of six hours of direct sunlight each day is necessary for optimum growth and yield.
Temperature Requirements
The ideal temperature range for the growth of Vigna unguiculata (L.) Walp. is between 25°C and 35°C. The minimum temperature required for its growth is 20°C, while the maximum temperature is 45°C. The plant is sensitive to frost and cannot withstand freezing temperatures.
Soil Requirements
Vigna unguiculata (L.) Walp. plants prefer well-drained soils that are rich in organic matter. Soil with a pH range of 5.5 to 7.5 is ideal for optimum growth. They can tolerate slightly acidic soil but do not grow well in alkaline soils. The plant is also sensitive to soil salinity, and therefore, it is important to avoid planting in areas with high soil salinity.
Cultivation methods
Vigna unguiculata (L.) Walp. or cowpea can be cultivated during the summer season in warm and humid regions. They grow best in well-drained sandy loam soil with a pH range of 6.0 to 7.5. The plant requires full sun and can grow up to 1-2 meters in height.
Watering needs
Cowpea requires a moderate amount of water during its growing season. The plant should be watered frequently, especially during the flowering and fruiting stage. Over-watering should be avoided as it can lead to the development of root rot.
Fertilization
Cowpea is a leguminous plant that can fix atmospheric nitrogen into the soil. However, a small quantity of nitrogen can be added during the initial stages of growth to promote better growth. Organic fertilizers like manure and compost can also be used sparingly to improve soil fertility and structure.
Pruning
The cowpea plant does not require heavy pruning. However, the plant should be pruned to remove dead and diseased branches. The pruning should be done in such a way that the structure of the plant is maintained. Pruning can also help in providing the plant with better air and sunlight circulation.
Propagation of Vigna unguiculata (L.) Walp.
Propagation is the process of multiplying a plant by natural or artificial means to perpetuate its existence. Here are some methods for propagating Vigna unguiculata (L.) Walp., commonly known as cowpea:
Seed sowing
Cowpea can be propagated by seed. Soak the seeds for 12-24 hours prior to sowing to improve germination. Sow the seeds in well-drained soil with a neutral pH. Keep the soil moist but not waterlogged. The seeds typically germinate within 7-10 days, and the seedlings can be transplanted into the garden or field once they have grown at least two sets of true leaves.
Vegetative propagation
Asexual propagation is another method used for propagating Vigna unguiculata. Cuttings may be taken from the plant's stem, and once treated with rooting hormones and planted into well-draining soil, they can root. Vegetative propagation is a preferred method of cowpea propagation as the plant is usually propagated to maintain specific characteristics, which can be lost when grown from seed.
Grafting
Grafting is another propagation method used for Vigna unguiculata. In grafting, a scion of the desired cultivar is grafted onto a rootstock of a different cultivar. Grafting can increase plant health and yields by utilizing the vigor of the rootstock and the desirable traits of the scion.
Propagation, whether sexual or asexual, helps maintain the existence of Vigna unguiculata and ensures that desirable traits are passed from one generation to the next.
Disease and Pest Management for Vigna unguiculata (L.) Walp.
Vigna unguiculata (L.) Walp. is commonly known as cowpea. The plant is susceptible to a range of pests and diseases.
Common Pests
The following are some of the common pests that may affect the growth and yield of cowpea:
- Cowpea aphid: An infestation of cowpea aphid can cause significant damage to the plant. Symptoms include stunting, yellowing of leaves, and distorted growth. A potent insecticide can be applied to control the aphids.
- Thrips: Thrips can cause extensive damage to cowpea by feeding on the leaves. Symptoms of thrip damage include silvery or white streaks on the leaves and premature dropping of leaves. Insecticides and regular removal of weeds can help control thrips.
- Pod borers: Pod borers tunnel into the developing seed pods, causing them to become deformed or rotten. Manual removal of affected pods and the use of insecticides can mitigate the damage caused by pod borers.
Common Diseases
Some of the common diseases that can affect cowpea include:
- Anthracnose: Anthracnose is a fungal disease that can cause spotting, yellowing, and eventually, death of leaves and stems. To prevent anthracnose, plant resistant varieties and remove and destroy infected plants and debris.
- Bacterial blight: Bacterial blight can cause water-soaked spots on leaves and stems that eventually turn brown. The disease spreads rapidly, and whole plants can die within days. Use copper-based fungicides to mitigate bacterial blight.
- Mosaic virus: Mosaic virus is a viral disease that can cause dwarfing, yellowing, or mottling of leaves. There is no cure for mosaic virus, and infected plants should be uprooted and destroyed to prevent the disease from spreading.
By following these disease and pest management strategies, growers can ensure healthy growth and yield of Vigna unguiculata (L.) Walp.
