How Much Rain Does Jatropha Need Per Year?

Rainfall Requirement

• Jatropha is drought-tolerant, with minimal water requirements, given its deep root system. The plant is able to thrive with 9 to 11 inches of rainfall per year, according to the Food and Agriculture Organization of the United Nations. However, at least 39 to 59 inches of annual rainfall are needed for optimal flower and fruit production. Unless the tree is growing in very well-drained soil, more than 100 inches of annual rainfall makes the trees prone to fungal diseases and affects root growth.

Site

• The tree thrives best in areas of full sun and does not adapt well to shade. Growth is optimal in deep, well-drained and aerated loam or sand with a preferred pH ranging between 6.0 and 8.5. Jatropha grows poorly in waterlogged or heavy clay soil. The tree is tolerant of harsh growth conditions, adapting to dry, poor-quality soil and able to extend roots even through rock crevices. However, productivity and yield are not high under poor cultural conditions.

Oil Content

• Jatropha seeds are likely to contain 18.4 to 42.3 percent oil. Oil content is generally 30 to 35 percent. The seed kernel contains the most oil, with 50 to 55 percent in the form of crude fat and protein. The seeds are ready for harvest 90 days after flowering, with ripeness indicated by the yellow-brown color. Fruit is harvested for two months in semi-arid areas and all through the year in regions with wet weather.

Tree Description

• Jatropha has a spreading growth habit with stubby twigs and a mature height of up to 19 feet. The twigs excrete a milky yellow liquid. The alternate leaves are ovate and 2 to 15 inches long. The yellow flowers are bell-shaped and are followed by 1-½-inch-long capsules with three valves containing black oblong seeds.