Overview
Jatropha urens L. is a perennial plant that belongs to the genus Jatropha and family Euphorbiaceae. It is commonly known as "physic nut", possessing a wide range of medicinal properties with potential use in biodiesel production. The oil extracted from the seeds has been used for various purposes in different industries.
Origin and Distribution
Jatropha urens L. is native to South America, but it has now spread throughout tropical regions across the globe. It is found commonly in tropical Africa, India, and Southeast Asia. The plant prefers warm and dry conditions and is usually found in arid and semi-arid regions.
Common Names
Some of the common names for Jatropha urens L. include “physic nut,” “purging nut,” “gout plant,” and “tubafu” in Swahili.
General Appearance
Jatropha urens L. is a small tree that can grow up to 5 meters in height and has a sprawling growth habit. The bark of the plant is smooth and greyish-brown in color. The leaves are dark green, large, and glossy. The plant bears greenish-yellow flowers that later develop into an ovoid fruit containing three seeds. The seeds are greyish-brown and covered with a thin, smooth seed coat.
Uses
The seeds of Jatropha urens L. are used for medicinal purposes due to their purgative and laxative properties. The oil extracted from the seeds has been used for lighting lamps, making soaps and candles, and more recently, for biodiesel production. The oil cake that is a by-product of the oil extraction is used as organic fertilizer as it contains high levels of nitrogen and potassium. The plant has also been used for erosion control and as a live fence.
Light Requirements
Jatropha urens L. thrives best under full sunlight exposure. The plant requires at least 6 hours of direct sunlight daily to achieve optimum growth and development. If the plant is grown in shaded areas, it may not flower or produce fruits as expected. Therefore, farmers are advised to plant them in areas with unobstructed access to sunlight.
Temperature Requirements
The plant can grow in different temperature ranges, but the optimum temperature for its growth is 20-30°C. Temperatures above 40°C and below 0°C will affect the growth and survival of the plant. The plant can tolerate drought, but frost may cause damage or slow growth rates. Therefore, it is ideal for the plant to be grown in areas with temperatures that are within the optimum range.
Soil Requirements
Jatropha urens L. is an adaptable plant that can grow in a wide range of soils, but it prefers well-drained soils. The plant can tolerate soils with a pH range of 5.5-8.5. However, the plant will not grow optimally in soils with pH levels that are too acidic or alkaline. Organic matter content should be at least 3% to improve soil fertility. Soil types that are suitable for growing Jatropha urens L. include loam, sandy loam, and clay loam.
Cultivation Methods
Jatropha urens L. is a hardy plant that is tolerant of various soil types. However, the ideal soil type for its growth is well-drained soil with a pH range of 6.0-7.5. The plant is propagated through seeds, cuttings, or tissue culture. Direct sowing of seeds is an easy and convenient way of growing the plant. Sow the seeds in rows with a spacing of 3 Ft. 8 inches. The plant requires full sun exposure to thrive, so plant it in a location with adequate sunlight.
Watering Needs
Water the Jatropha urens L. plant consistently to promote healthy growth. The plant requires regular watering once every week during the growing season to thrive. However, the frequency of watering will depend on the climate and soil type. Avoid flooding the plant with water as it can lead to root rot and other diseases.
Fertilization
Jatropha urens L. requires proper fertilization throughout its growing period to increase crop yield and improve the quality of the produce. Apply organic compost to the soil before planting, and add supplements like nitrogen, potassium, and phosphorous to boost growth and development. During the growing season, apply a balanced fertilizer every two to three weeks to keep the plant healthy.
Pruning
Prune the Jatropha urens L. plant annually to maintain its shape and promote healthy growth. Cut weak or diseased branches promptly to prevent the spread of diseases to other parts of the plant. Pruning also encourages the development of new shoots and increases the yield of the plant. The best time to prune the plant is during the winter dormant period.
Propagation of Jatropha urens L.
Jatropha urens L. is commonly propagated by seeds, stem cuttings, and air layering. In commercial plantations, the most common method of propagation is through seeds. However, stem cuttings and air layering have also shown promising results in producing uniform and high-quality planting material.
Propagation by Seeds
Propagation by seeds is the easiest and most common method for Jatropha urens L. Seeds should be collected from mature and healthy fruits. The seed coat is hard, and it needs to be scarified, soaked, or both to hasten the germination process. Soaking seeds in water for at least 24 hours before planting helps soften the hard seed coat and raise the germination rate. Sowing seeds directly in the ground or in containers filled with well-drained soil is ideal. Seeds should be planted at a depth of 2-3 cm. Regular irrigation and maintenance are required for proper seed germination and establishment of seedlings.
Propagation by Stem Cuttings
Propagation by stem cuttings is relatively easy with Jatropha urens L. Softwood cuttings are taken from the mother plant, treated with rooting hormones to promote rooting, and planted in well-drained media. The cuttings should be approximately 10-15 cm long, with two to three nodes. After planting, cuttings should be placed in a well-lit, warm area and maintained moist. With proper care, cuttings will develop a sufficient root system within two to four weeks.
Propagation by Air Layering
Air layering is a vegetative propagation method in which a branch from the mother plant is wounded and treated with rooting hormones and wrapped with a moist growing medium and plastic wrap to create a mini greenhouse-like environment. Roots will emerge from the wound within six to eight weeks. Once roots are visible, the newly developed plant can be cut from the mother plant and planted in a new location. Air layering is a slow process compared to other propagation methods but is a reliable way to produce clones of exact replicas of the desired plant.
Disease and Pest Management for Jatropha urens L.
Jatropha urens L. is a hardy plant that is resilient to pests and diseases. However, there are some common diseases and pests that can affect the plant, and it is essential to manage them properly to ensure healthy growth and high yield. Here are some common diseases and pests that may attack Jatropha urens L. and ways to manage them.
Diseases
Leaf spot is a fungal disease that causes circular spots on the leaves and damages the plant's quality and yield. The disease spreads in wet conditions and hot weather. Control the disease by removing infected leaves, maintain the plant clean, and provide adequate drainage to prevent waterlogging.
Root rot is a fungal disease caused by Pythium. The disease weakens the plant and eventually leads to death. To manage root rot, provide well-drained soil, remove infected plants, and ensure that the plant gets proper watering.
Pests
Caterpillars can cause extensive damage to the plant by feeding voraciously and leaving holes on the leaves. To manage caterpillars, pick and destroy them during the early stage, or use a natural pesticide to control them.
Mites are tiny pests that suck sap from the leaves, causing yellowing and curling of leaves and reducing the plant's health. Apply neem oil or a natural pesticide to control the pests.
Aphids feed on the sap of the plant and secrete honeydew, causing leaves to curl and turn yellow. Control by spraying with soapy water or neem oil.
It's crucial to keep monitoring the plants regularly for any signs of pests or diseases. Early detection and prompt management can prevent severe damage, reducing the need for pesticides and ensuring they do not harm the environment.
