Overview
Vigna unguiculata (L.) Walp. var. protracta (E.Mey.) Verdc., commonly known as the Cowpea, is a climbing herbaceous plant that belongs to the Fabaceae family.
Origin
The Cowpea is native to Africa, particularly sub-Saharan areas. It was domesticated between 3000 and 3500 years ago and has since been widely cultivated and traded across Africa, Asia, America, and Europe.
Common Names
The Cowpea is known by several names, including black-eyed pea, southern pea, yardlong bean, and catjang.
General Appearance
The Cowpea is a fast-growing and drought-tolerant plant that can reach up to 2 meters in height. It has compound leaves with three leaflets that are ovate to lanceolate in shape and measure up to 15 cm long. The plant produces long and slender pods that can range from 15 to 60 cm in length and can contain up to 20 seeds. The seeds are usually round or oval and can vary in color from white, green, brown, red, to black. The plant has a deep root system that helps it withstand drought and high temperatures.
Uses
The Cowpea has many uses, both as a food crop and as a source of animal feed. The seeds can be harvested and consumed fresh, dried, canned, or ground into flour. In some cultures, the leaves and flowers of the plant are also edible. The Cowpea is an excellent source of protein, fiber, minerals, and vitamins. It is also used in traditional medicine to treat various ailments such as diarrhea, constipation, and high blood pressure. Additionally, the plant is often used in soil improvement programs, as it is nitrogen-fixing, meaning it can help enrich the soil and improve crop yields. Farmers can also use the cowpea as a cover crop to control soil erosion and suppress the growth of weeds.
Light Requirements
Vigna unguiculata (L.) Walp. var. protracta (E.Mey.) Verdc. requires full to partial sunlight to thrive and produce a healthy yield. Therefore, it is important to plant this species in an area that receives direct sunlight for at least six hours each day. If possible, place the plant in a location that is protected from strong winds, which can damage the leaves and reduce growth.
Temperature Requirements
The ideal temperature range for Vigna unguiculata (L.) Walp. var. protracta (E.Mey.) Verdc. growth is between 25°C to 35°C. At temperatures outside this range, the plant will either fail to thrive or experience reduced growth. It is important to note that the seedlings of this species are very sensitive to low temperatures, which can cause death. Therefore, it is essential to ensure that the plant’s growth conditions are consistently within the recommended temperature range.
Soil Requirements
Vigna unguiculata (L.) Walp. var. protracta (E.Mey.) Verdc. thrives in well-drained soils with good organic matter content. The soil should have a pH range of 6.0 to 7.5. The plant can grow in sandy, loamy, or clayey soils, but it favors well-drained sandy loam soils with high fertility. Before planting, one should add well-rotted farmyard manure or compost to the planting area to ensure the soil is fertile and ready for growth.
Cultivation methods
Vigna unguiculata (L.) Walp. var. protracta (E.Mey.) Verdc. is a warm-season crop that thrives in tropical and subtropical regions. The plant can adapt to different types of soil, but it grows best in well-drained sandy loam with a pH of 6.0-7.5. The seeds should be planted 1-2 inches deep and 2-4 inches apart in rows with a spacing of 24-36 inches. The best time to sow the seeds is during the early onset of the rainy season or when there is a reliable source of irrigation.
Watering needs
Vigna unguiculata (L.) Walp. var. protracta (E.Mey.) Verdc. requires moderate watering during its growth cycle. In the early stages of growth, the plants require regular watering to establish a robust root system. The frequency of watering should be reduced as the plant matures to prevent waterlogging that can cause root rot. It is recommended to water the plants early in the morning or late in the afternoon to minimize water loss through evaporation.
Fertilization
The use of organic manures or fertilizers is recommended for Vigna unguiculata (L.) Walp. var. protracta (E.Mey.) Verdc. to improve soil fertility and increase productivity. A balanced fertilizer application of NPK 15-15-15 at a rate of 120 kg/ha is recommended for optimal growth. Application of fertilizers should be done after two weeks of planting, and then at four weeks interval until the plant matures. Organic manures can also be applied at a rate of 20-30 tonnes per hectare.
Pruning
Pruning is essential for Vigna unguiculata (L.) Walp. var. protracta (E.Mey.) Verdc. to promote bushy and compact growth, improve light penetration, and increase yield. The plant should be pruned when it reaches a height of 15-20 centimeters by pinching off the terminal bud. This will stimulate the emergence of new branches and increase the number of pods per plant. The side branches should also be pruned to maintain a compact canopy that allows for proper aeration and light penetration.
Propagation of Vigna unguiculata (L.) Walp. var. protracta (E.Mey.) Verdc.
Vigna unguiculata (L.) Walp. var. protracta (E.Mey.) Verdc. can be propagated by seed, cuttings, and grafting.
Seed propagation
Seeds should be sown in well-draining soil in a warm and sunny location. The seeds germinate quickly and emerge within 4 to 6 days. It is important to ensure that the soil is kept moist but not waterlogged. Once the seedlings are about 10cm tall they can be transplanted into individual containers or the ground.
Cuttings propagation
Cuttings taken from mature plants can be propagated in a moist soil mix. The cuttings should be about 10cm long and have at least 2 leaves attached. Remove the lower leaves and place the stem in moist soil. Place the pot in a warm and well-lit location. The cutting should root within a couple of weeks.
Grafting propagation
Grafting can be used to propagate Vigna unguiculata (L.) Walp. var. protracta (E.Mey.) Verdc. Grafting is the process of joining two plants into one, where one plant provides the rootstock (root system) and the other provides the scion (top portion). Grafting is a specialized technique that requires skill and knowledge, but it can produce strong and disease-resistant plants. For this reason, it is often used for commercial plant production.
Disease Management
Vigna unguiculata (L.) Walp. var. protracta (E.Mey.) Verdc. is susceptible to several diseases, which can significantly affect its growth and yield. Here are some of the most common diseases and ways to manage them:
Bacterial blight
Bacterial blight can cause wilting, yellowing, and eventually death of the leaves and stems. The disease spreads through water and infected plant debris. To manage this disease, remove and destroy infected plant materials, avoid watering the plant from above, and use copper-based fungicides.
Fusarium wilt
Fusarium wilt can cause yellowing and wilting of the leaves, followed by plant death. Infected soil can transfer the pathogen to the plant roots, and it can spread through irrigation water. To manage this disease, use resistant cultivars, rotate crops, and sterilize the soil in between crops.
Root rot
Root rot can cause stunted growth and yellowing of the leaves, leading to plant death. Excessive moisture and poor drainage favor the development of this disease. To manage this disease, avoid overwatering, improve soil drainage, and use fungicides containing Trichoderma or Bacillus spp.
Pest Management
Vigna unguiculata (L.) Walp. var. protracta (E.Mey.) Verdc. is also vulnerable to attack by several pests, which can cause considerable damage to the plant. Here are some of the most common pests and ways to manage them:
Bean aphid
Bean aphids can cause yellowing and curling of the leaves, and the production of sticky honeydew that attracts ants. To manage this pest, introduce natural predators such as ladybugs or lacewings, use insecticidal soaps or oils, or spray with neem-based products.
Moths and caterpillars
Moths and caterpillars can feed on the leaves and pods, causing significant damage to the plant. To manage these pests, use Bacillus thuringiensis (Bt) sprays, handpick and destroy visible caterpillars, or use pheromone traps to disrupt mating.
Leafhoppers
Leafhoppers can cause yellowing, stunted growth, and the production of white stippling on the leaves. The insects can also spread diseases like phytoplasma. To manage this pest, introduce natural predators such as spiders or parasitoid wasps, use insecticidal soaps or oils, or spray with pyrethrin-based products.
