Production components of Jatropha under irrigation and nitrogen fertilization in the semiarid region of Ceara

Jatropha curcas L. proves to be a promising species, considering its inclusion in the National Program of Biodiesel Production and Use. However, since it has not been genetically improved, agronomic information is still scarce in the literature, especially under conditions of water and nutritional stress. Thus, this field study aimed to evaluate the effects of irrigation depths (735; 963; 1,191; 1,418 and 1,646 mm) and nitrogen fertilization (0; 25; 50 and 75 kg ha (1)) on the production of Jatropha plants. Plants under the highest irrigation depth showed the highest values of number of fruits and productivity of fruits, seeds and albumen. Plants under the irrigation depth of 1,191 mm showed the highest values of mean mass of albumen and the ratios between mass of albumen and mass of seeds and between mass of albumen and mass of fruits. Nitrogen fertilization did not influence the production components of Jatropha.