Overview of Jatropha curcas L. var. glabrata Schumach. & Thonn.
Jatropha curcas L. var. glabrata Schumach. & Thonn., also known as "wild castor" or "barbados nut," is a species of flowering plant in the Euphorbiaceae family. It is a small tree or shrub that is native to tropical regions of Central and South America, but is now widely distributed throughout tropical and subtropical regions of the world.
Appearance
Jatropha curcas L. var. glabrata Schumach. & Thonn. is a small tree or shrub that typically grows up to 5 meters in height, but may reach up to 7 meters in optimal conditions. It has a single stem, which may be straight or crooked, and a roundish crown of branches. The leaves are simple and alternate, measuring 7-15 cm in length and 4-10 cm in width, and are glossy green in color. The flowers are small and greenish-yellow in color, growing in clusters on the upper part of the stem. The fruit is a large, green capsule with three cells, each containing one or two dark brown or black seeds.
Common Uses
Jatropha curcas L. var. glabrata Schumach. & Thonn. has been used for a wide range of purposes throughout history. The seeds of the plant are toxic, but they can be processed to produce non-edible oil, which has been used for various purposes such as soap-making, lubricants, candles, and biofuels. The plant has also been used for medicinal purposes, particularly in traditional medicine, to treat ailments such as constipation, skin diseases, and headaches. Additionally, the plant has been used in landscaping, as a hedge or as an ornamental plant, due to its attractive appearance and dense foliage.
Light Requirements
Jatropha curcas L. var. glabrata Schumach. & Thonn. requires full sunlight exposure for optimal growth. It is a sun-loving plant that requires at least 6 hours of direct sunlight daily. Insufficient sunlight exposure may cause stunted growth or even death.
Temperature Requirements
Jatropha curcas L. var. glabrata Schumach. & Thonn. thrives in warm to hot environments, with an optimal temperature range between 25°C to 35°C. It can tolerate temperatures as low as 10°C but growth will slow down. Extreme temperatures below 5°C or above 45°C can be fatal to the plant.
Soil Requirements
The plant requires a well-draining soil that is rich in nutrients. A sandy, loamy soil with a pH range between 6.5 to 7.5 is ideal. The soil must be able to retain some moisture, but not waterlogged. The plant can grow in a wide range of soils, but it is most productive in soils with good fertility and high organic matter content.
Cultivation Methods
Jatropha curcas L. var. glabrata Schumach. & Thonn. is a shrub that prefers a warm climate and grows best in well-drained soils. It is recommended to plant the seeds during the rainy season, preferably in soil with a pH ranging from 6 to 7.5. The seeds should be sown at a depth of 2-3 cm and at a distance of 2-3 meters from each other. The shrub can grow up to 5-8 meters in height.
Watering Needs
Jatropha curcas L. var. glabrata Schumach. & Thonn. is a drought-resistant plant and can tolerate dry conditions. However, during the initial growth phase, it is important to water the plants regularly to promote root development. Once the plants are established, they only need occasional watering. It is important not to overwater the plants as this can lead to root rot and other diseases.
Fertilization
Jatropha curcas L. var. glabrata Schumach. & Thonn. responds well to organic fertilizers such as compost and manure. The application of nitrogen-rich fertilizers should be avoided as it can affect the development of flowers and seeds. It is recommended to apply fertilizers during the rainy season to ensure optimum growth and yield.
Pruning
Pruning is an important aspect of Jatropha curcas L. var. glabrata Schumach. & Thonn. cultivation as it helps to promote growth and shape the plant. Shrubs should be pruned in the early years of growth to develop a strong framework of branches. Pruning should be done during the dormant period, preferably after the fruiting season. It is important to remove all dead, diseased, or broken branches and maintain an open canopy to improve air circulation and light penetration to the lower parts of the plant.
Propagation of Jatropha curcas L. var. glabrata Schumach. & Thonn.
Jatropha curcas L. var. glabrata Schumach. & Thonn. can be propagated through several methods, including:
Seed propagation
Seeds are the most common and easiest way to propagate Jatropha curcas. Collect mature fruits from the plant and let them dry in the shade for a few days. Once the fruits are dry, extract the seeds and clean them with water. The seed can be put in a nursery bed or directly in the field. Germination usually occurs within 10-15 days.
Cutting propagation
Jatropha curcas can also be propagated through stem cuttings. Select healthy stems that are approximately 15-20 cm long and without any pests or diseases. Cut the stem at a 45-degree angle and make sure to remove all leaves except the top two or three. Dip the cut end into rooting hormone powder and then place it in a nursery bed or directly in the field. Keep the soil moist, and in approximately 30-40 days, the stem cuttings will start to grow roots and shoots.
Layering propagation
This method involves bending a branch of the plant and burying it a few inches deep in the soil. Remove the bark from the bent part of the stem and cover it with soil. Once roots have formed, sever the rooted stem from the mother plant and transplant it into a nursery bed or directly in the field.
Grafting propagation
Grafting is a common propagation method for Jatropha curcas. It involves joining a cutting from the desired plant (scion) onto the rootstock of a different plant. Grafting is done in the spring or early summer when the plant is actively growing. This method allows for the production of clones, which ensures the same desirable characteristics of the parent plant.
Disease Management
Jatropha curcas L. var. glabrata Schumach. is susceptible to various diseases that can cause significant damage to the plant and reduce its yield. Some common diseases that affect the plant are:
- Leaf spot disease: Fungal pathogens like Cercospora jatrophae, Phyllosticta jatrophae, and Septoria jatrophae cause leaf spot disease, which shows up as dark, irregular-shaped spots on the leaves. This can result in defoliation and weakening of the plant.
- Mosaic virus: This virus causes yellow or light green mottling on the leaves and stunts the growth of the plant.
- Root rot: This fungal disease is caused by various fungi-like Fusarium spp., Phytophthora spp., and Rhizoctonia spp. The infected plant shows wilting and yellowing of leaves, reduced growth and eventually dies.
To manage the diseases, it is essential to adopt a preventive approach, which includes the following:
- Plant resistant varieties
- Rotation of crops with non-host plants
- Sanitation practices to remove infected plant materials
- Proper drainage and irrigation systems to prevent waterlogging
- Use biocontrol agents, such as Trichoderma spp. and Bacillus spp.
Pest Management
Jatropha curcas L. var. glabrata Schumach. is also susceptible to pests that can damage the plant and reduce its yield. Some common pests include:
- Mealybugs: These sap-sucking insects feed on the plant's sap and excrete honeydew, leading to the growth of sooty mold. The plant shows yellowing and stunted growth.
- Budworms: These pests feed on the buds and flowers of the plant, leading to a reduction in the yield of seeds.
- Jatropha fruit fly: The larvae of this fly feed on the seeds of the plant, damaging the yield.
Integrated Pest Management (IPM) strategies can help manage the pests. These include:
- Use of insect traps and natural predators
- Application of organic pesticides such as neem oil and insecticidal soap
- Regular scouting to detect and remove infested plant material
- Cultivation of companion plants that repel or attract pests
