Initial growth of Jatropha curcas L. in response to different substrates and nitrogen sources.

The physic nut, Jatropha curcas L., belongs to Euphorbiaceae family and it has potential to produce oil for biodiesel what in turn has raised the researcher’s interest as observed by the increasing of studies on this culture. The present research was aimed at study the effect of two different substrates: S1 clay soil and S2 clay soil:sand, in proportion 1:1, and three nitrogen sources (N1 – ammonium sulfate ((NH4)2SO4); N2 – calcium nitrate (Ca(NO3)2.4H2O); N3 –urea ((NH2)2 CO)), on the early growth of physic nut. The trial was conducted in an environment with 50% shade. Treatments were arranged in a factorial 4 x 2, correspond respectively to the nitrogen sources, experimental control (absence of N) and substrates. The treatments were arranged according to a completely randomized design (CRD) with five repetitions. The growth conditions that lead to better results were those in which the seedlings were grown in substrate S2, and received as nitrogen sources urea and calcium nitrate.