COWPEA (Vigna unguiculata), The cowpea is a member of the pulses or legumes.
Cowpea (Vigna unguiculata) is a legume crop that belongs to the Fabaceae family. It is also known by various other names such as black-eyed pea, southern pea, and crowder pea.
Cowpea is a widely cultivated crop, especially in the tropical and subtropical regions of the world. It is valued for its nutritious seeds and its ability to fix nitrogen in the soil.
Here are some key features and characteristics of cowpea:
Plant Description: Cowpea plants are annual and can be either erect or climbing, depending on the variety. They have a deep taproot system that helps in accessing water and nutrients from the soil. The leaves are trifoliate and alternately arranged on the stem.
Flowers and Pods: Cowpea plants produce small, white or lavender-coloured flowers that are usually self-pollinated.
The flowers are followed by elongated pods, which can vary in colour from green to purple or brown, depending on the variety. Each pod contains several seeds.
Seed Varieties: Cowpea seeds come in various shapes, sizes, and colours. The most common type has a cream-coloured seed coat with a prominent black spot, giving it the name \”black-eyed pea.\”
However, there are also varieties with white, red, brown, or speckled seed coats.
Nutritional Value: Cowpea seeds are rich in protein, dietary fibre, vitamins (such as folate and vitamin B6), and minerals (such as iron, potassium, and magnesium).
They are also low in fat and cholesterol, making them a healthy addition to the diet.
Culinary Uses: Cowpea seeds are consumed in many different ways across different cultures. They can be boiled, steamed, or roasted and used in soups, stews, salads, and various traditional dishes.
The tender leaves and shoots of cowpea plants are also edible and can be cooked and consumed as a vegetable.
Agronomic Importance: Cowpea is highly valued in agricultural systems due to its ability to fix atmospheric nitrogen through a symbiotic relationship with nitrogen-fixing bacteria present in its root nodules.
This makes cowpea a beneficial rotational crop, as it enriches the soil with nitrogen, benefiting subsequent crops.
Drought Tolerance: Cowpea is known for its ability to tolerate drought conditions and high temperatures. It can adapt to a wide range of climatic conditions and soil types, although it prefers well-drained soils.
These characteristics make cowpea a suitable crop for regions with limited water availability.
Economic Importance: Cowpea is an important crop for both small-scale farmers and commercial agriculture. It serves as a source of food and income, particularly in developing countries.
Cowpea is also used as fodder for livestock and is considered a valuable crop for sustainable farming systems.
Land Preparation for the planting of cowpea
The land is cleared after which the thrash is packed. Weed-row burning can also be done. The land preparation is continued with stumping, ploughing, harrowing and ridging done in sequence.
Varieties of cowpea or Cultivars
Erect type, creeping type, Ife brown, Ife Bimpe etc.
Climatic and Soil Requirement for cowpea :
Cowpea requires a temperature of 27°C – 3 5°C, rainfall of 60cm – 125cm per annum, abundant sunshine and a rich sandy loamy soil.
Method of propagation of cowpea:
By seeds. Planting date: Early and late planting are in April and August respectively. In the South, early planting is April while late planting is August and September.
In the North, late planting is July and August. Seed rate: 20-25 kg/ha.
Spacing: It depends on variety. For example, spacing for the spreading type is 25 x 90cm while the erect type is 30 x 75 cm.
Planting: There should be seed dressing before planting. Planting can either be manual or mechanized. Seeds are planted directly on the field.
Planting depth of 2-4 cm is allowed. Planting rate is two to three seeds in a hole, while germination occurs between three to five days after planting.
Cultural Practices in cowpea cultivation
(i) Thinning: This can be done when the plants are about two to five weeks of age.
(ii) Weeding: Weeding can be done manually on a small scale while herbicides can be applied on commercial scale.
Weeding is usually carried out once or twice before the plant spreads fully.
(iii) Fertilizer application: Apply phosphatic fertilizer for nodulation and pod formation.
Apply the fertilizer at land preparation or at planting. Rate of application should be 250kg or five bags per hectare.
Maturity period or stages of cowpea :
Cowpea matures between three to four months after planting.
Harvesting method of cowpea:
Brown, mature or ripe pods c harvested by hand-picking. Early varieties are harvested three months after planting while late maturing varieties are harvested after four months.
Harvest mature dry pods before shattering. read methods of crop harvesting here
Processing method in cowpea production :
Harvested pods are dried under the sun. Shelling is done by beating the dry pods with sticks or by pounding lightly in a mortar on a small scale.
Shellers are used on a large scale. Winnowing is carried out whereby broken shells or pods are removed from the beans. Extraneous matter like stones are later removed.
(i) Ensure proper drying before storage
(ii) Shelled beans are treated with insecticides before storage to prevent weevil’s attack.
(iii) Shelled seeds are stored in bags or rhombus on a small scale.
(iv) Storage is done in silos on a large scale.
(v) Hermatic storage can also be done in airtight containers.
How to Store cowpea :
The seeds are stored in jute bags.
Pests of Cow-pea and their control methods
(1) Pod borers: Adults pierce or bore holes into fruits and stems and may inject toxic saliva.
Control: Spray with insecticide
(2) Bean beetle (Callosobruchus spp): This is a field-to-store pest. Adults and nymphs bore holes into seed, feed on them and turn them to powder, thereby reducing the quality and market value.
(i) Early harvesting of pods
(ii) Fumigation of containers or store with fumigant like phostoxin tablets
(3) Leaf Hoppers: They eat up the leaves, thereby causing low yield of crops.
Control: Spray plants with insecticides
Diseases of Cowpea and their control methods
(1) Cowpea mosaic disease: It is a viral disease which is transmitted by aphid or thrip. It causes stunting, reduces pod size and cause premature dropping of flowers.
(i) Use resistant varieties
(ii) Control insect vector by spraying with pesticides
(iii) Remove and burn infected plants
(2) Bacterial blight: It is caused by a bacterium which is spread by water as insect-borne disease. Infected leaves produce water-soaked spots which later enlarge and turn brown
(i) Use resistant varieties
(ii) Use clean seeds when planting
(3) Nematode disease: It is caused by nematode transmitted through soil. It cause twisting, rolling of roots.
(i) Use resistant varieties
(ii) Practice good cultural operations
(iii) Treat soil with nematicide
(4) Damping-off disease: This disease is caused by a fungus (Phytophthora spp). It is transmitted through the hyphae in the soil. It results in the destruction of seedlings in the soil
(i) Dress seeds with fungicides
(ii) Practice crop rotation
(iii) Grow resistant varieties
(iv) Remove infected plants
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