Jatropha plant is mainly grown for its seeds which when crushed, the resulting jatropha oil can be processed to produce a high-quality biofuel or biodiesel that can be used in a standard diesel car or further processed into jet fuel, while the residue (press cake) can also be used as biomass feedstock to power electricity plants, used as fertilizer (it contains nitrogen, phosphorus and potassium), or as animal fodder. The cake can also be used as feed in digesters and gasifiers to produce biogas.
Ecological requirements
Rainfall:300-1500mm annually
Altitude:300-1650
Temperature:18-280C
Soils: Does in all soils except heavy soils/vertisols
Land preparation
Plough the land during dry spell, remove all weeds and stumps if any. Add 10kg of organic manure per meter square. Harrow the field to a medium tilth.
Planting
Spacing- 2m by 2m, 2.5m by 2.5m or 3m by 3m
Direct seeding- soak seeds overnight and sow them directly in the field at a depth of 2-3cm in holes 45cm by 45cm by 45cm.
Nursery sowing-Raise seedlings on a raised nursery bed, transplant 4-6 months when seedlings are 30-40cm tall.
Vegetative propagation –Obtain cuttings 60-120cm long from mature trees. Cuttings are placed 20cm deep 1-2 months before the onset of rains.
Manure and fertilizer application
Apply 10-15 tons of organic manure and 50kgP per hectare during planting. Top dress with 90kgN per hectare.
Inter cropping
Intercrop with short crops like beans, green grams, cow peas, onions and tomatoes. Legumes are preferred as they will aid in nitrogen fixation, this can reduce the amount of fertilizer used to enrich the soil with nitrogen.
Pruning
Its one of the important tree management, prune the trees up to a height of 2m high to allow easy crop management practices such as spraying and harvesting.
Weed control
The field should be kept weed free throughout the growing period. Carry out weeding 2-3 times yearly either using herbicides or shallow cultivation. For shallow cultivation ensure the moisture content of the soil is optimum to avoid loss of moisture following soil turning.
Pest management
Golden flea beetle- Use broad spectrum insecticide
Millipedes- Use broad spectrum insecticide
Spider mites- Use suitable miticide eg dynamic
Disease management
Powdery mildew- Use suitable fungicide eg ortiva
Alternaria leaf spot- Use a broad-based fungicide eg ridomil or cupra cafaro
Harvesting
The crop is ready for harvesting 8 months after planting when cuttings are used, 4-6 months when seedlings are used. Maturity index, the fruits turn from green to yellow. Yield range from 4.8-12 tons per hectare.
Crop utilization
- Making biodiesel, soap and dye
- Seedcake used as organic manure, leaves used as silk worm feed
- Roots used as snake bite anti dote, tender twigs used to clean teeth, skin diseases management as it contains anti-cancerous properties.