In this context it is important to note that Jatropha is not a domesticated plant — many varieties grow in the wild and there are at least 200 of them. It will need a lot more research to “standardize” the best qualities. This means breeding and multiplying Jatropha plants with the highest oil yields, the lowest water require­ments, and the most resistance against diseases on many soil types in different climates.

Breeding objectives will depend on its use. Oil yield will, in most cases, be the most important part of Jatropha cultivation. Components that contribute to the Jatropha oil yield per hectare are shown in Figure 3.1.

As the maximum number of seeds per capsule is limited and the agronomic factor of planting density does not offer much flexibility for increasing yields, selection should focus on the other yield components like number of female flowers, pollination rate, and so on. An important research objective is also to reduce the plant height to facilitate harvesting.

Number of Female Flowers

Figure 3.1 Seed yield factors affecting the yield of Jatropha seeds. Source: CPE — Mother Earth Business Plan.

3.1.13