Overview
Cajanus scarabaeoides (L.) Thouars, also known as Pigeonpea, is a perennial legume that belongs to the Fabaceae family. It is widely cultivated for its edible seeds and as a forage crop in various parts of the world. This plant is drought tolerant and can grow in a wide range of soil conditions, making it a popular choice for dryland agriculture.
Origin and Distribution
Cajanus scarabaeoides is native to tropical and subtropical regions of Africa, Madagascar, and the Arabian Peninsula. It commonly grows in savannas, woodlands, and semi-arid regions. The plant has been introduced to other parts of the world, such as Asia, Oceania, and the Americas, where it has become naturalized in some areas.
Common Names
Aside from Pigeonpea, Cajanus scarabaeoides is also known by other common names, depending on the region. Some of these include Wild Pigeonpea, Congo Pea, Sweet Pea, and Angola Pea.
Uses
The seeds of Cajanus scarabaeoides are widely consumed as a food source, especially in India, where the plant is an important crop. The seeds are often split and hulled before being cooked as a dal or added to soups and stews. The leaves and young shoots of the plant are also edible and are used as a vegetable in some regions.
In addition to its use as a food crop, Cajanus scarabaeoides is also cultivated as a forage crop for livestock. The plant's deep roots and tolerance for drought make it a valuable crop for areas with low rainfall and poor soil conditions.
Appearance
Cajanus scarabaeoides is a shrub or small tree that can reach a height of up to 4 meters. It has compound leaves that are alternately arranged on the stem. The leaves are pinnately compound, with three to eight leaflets that are ovate to lanceolate in shape and have a smooth surface. The flowers of the plant are yellow, orange, or purple and are clustered at the end of the branches. The fruit is a pod that is cylindrical in shape, and the seeds are small and round, with a characteristic mottled appearance.
Light Requirements
Cajanus scarabaeoides (L.) Thouars is a plant that thrives well in full sun to partial shade. It requires at least 6 hours of direct sunlight to grow. When it's grown in shaded areas, it may fail to thrive and also have poor quality blooms.
Temperature Requirements
This plant commonly grows in tropical and subtropical climates, which means that it requires a warm temperature to grow. Cajanus scarabaeoides (L.) Thouars thrives in temperatures ranging from 65°F to 85°F. It can survive in areas with temperatures reaching 90°F during the day and 60°F at night. When grown in colder climates, it requires special attention to survive.
Soil Requirements
Cajanus scarabaeoides (L.) Thouars prefers well-drained soils that are fertile, loose, and have a pH ranging from slightly acidic to neutral. It can grow in different types of soils, which include sandy, clay, and loamy soils. For optimal growth, the soil should be rich in organic matter, such as compost. Additionally, this plant requires a soil with enough moisture content, but not too much, as it can lead to root rot.
Cultivation Methods
Cajanus scarabaeoides, also known as the wild pigeon pea, is a hardy plant that can be grown both indoors and outdoors. It prefers warm to hot temperatures and well-drained soil. The plant can be grown from seeds or cuttings, and it is advisable to soak the seeds overnight before planting to improve germination rates. The plant needs full sun exposure for optimum growth.
Watering Needs
Wild pigeon pea requires regular watering, especially during the dry season. However, waterlogging should be avoided as it can lead to root rot. The plant can be watered once or twice a week, depending on the prevailing weather conditions and soil moisture levels. It is advisable to water the plant in the early morning or late afternoon to reduce water loss through evaporation.
Fertilization
For maximum growth and healthy foliage, wild pigeon pea requires regular fertilization. A balanced fertilizer with a nitrogen-phosphorus-potassium (NPK) ratio of 4:2:3 is ideal. The fertilizer should be applied during the growing season at intervals of 4-6 weeks. Overfertilization should be avoided as it can lead to excessive vegetative growth at the expense of flowering and fruiting.
Pruning
Pruning is an essential aspect of wild pigeon pea cultivation. It promotes robust growth and enhances branching, leading to more flowers and pods. The best time to prune is during the dormant season (winter) or after flowering and fruiting. Dead, diseased or damaged parts should be removed, and weak shoots thinned out to allow for more sunlight penetration and improve airflow. Pinching off the tips of the growing shoots can also encourage bushier growth and improve the overall shape of the plant.
Propagation of Cajanus scarabaeoides
Cajanus scarabaeoides, also known as wild pigeon peas, belong to the family Fabaceae and are native to Africa. It is a woody, perennial shrub that can reach up to 2 meters in height and is widely grown as a forage crop, green manure, and as an ornamental plant. Propagation of Cajanus scarabaeoides can be done through the following methods:
Seed propagation
Seed propagation is the easiest and most common method of propagating wild pigeon peas. The seeds should be scarified or nicked using sandpaper before sowing, allowing them to absorb water more quickly. The seeds should be sown at a depth of 5-10 cm in well-draining soil. Germination should occur within 7-10 days, and the seedlings are ready for transplanting after 2-3 months.
Cutting propagation
Cutting propagation can also be done to propagate Cajanus scarabaeoides. Softwood cuttings from the young shoots should be taken during the active growing season, typically in late spring or early summer. The cuttings should be treated with rooting hormone before planting in a well-draining soil mix. They should be kept in a warm, humid environment and misted regularly until they develop roots, which usually takes 3-4 weeks.
Division propagation
Division propagation can be done for mature plants that are several years old. The plant should be carefully dug up and the roots separated into smaller sections. Each section should have several shoots and a good root system. The divided plant should be replanted immediately in a well-draining soil mix and watered well. The new plants should be kept in a warm, protected location until they develop new shoots.
Disease Management
Cajanus scarabaeoides is relatively resistant to pests and diseases. However, it can be affected by fungal and bacterial diseases that can lead to significant yield and quality loss.
Leaf Spot
Leaf spot is a fungal disease that causes small, circular spots on leaves. The spots may be brown or black, with yellow halos. This disease can be controlled by removing the infected leaves and spraying the plant with a fungicide. Adequate spacing between the plants also reduces the incidence of this disease.
Anthracnose
Anthracnose is another fungal disease that affects the plant's leaves, stems, and pods. The infection starts as small, circular spots that gradually increase in number and size. The spots become sunken and turn brown or black. The disease can be controlled by removing the infected parts of the plant and using a copper-based fungicide.
Pest Management
Cajanus scarabaeoides is susceptible to a few pests, but they rarely cause significant damage. However, it is essential to monitor the plant for pests and take appropriate control measures on noticing an infestation.
Aphids
Aphids are small insects that suck the sap from the plant's leaves and stems, causing yellowing and curling of leaves. They reproduce quickly and can cause widespread damage. Aphids can be controlled using insecticidal soaps or neem oil. Encouraging natural predators such as ladybugs and lacewings can also help control aphid populations.
Spider Mites
Spider mites are tiny pests that suck sap from the leaves, causing them to turn yellow and eventually die. These pests can be controlled by spraying the plant with water and washing them off. Introducing predatory mites or using insecticidal soap can also be effective in controlling spider mites.
Regular monitoring and management of pests and diseases can help maintain optimal growth and yield of Cajanus scarabaeoides plants.
