Viability of Jatropha curcas (euphorbiaceae) seeds in different stages of physiological maturity

Abstract. Jatropha curcas L. is an oilseed shrubby species still in process of domestication, from the Euphorbiaceae family, commonly known as pinho manso. The object of the present work was to verify if the germination of Jatropha curcas seeds is influenced by the harvest method or the seeds maturity stage. The seeds were picked at University of Brasilia farm. The pulps were extracted and germinated. The treatments consisted in: (T1) intact seeds of black fruit (witness), (T2) seed without black fruit tegument, (T3) black fruit seed with skin harvested from the ground, (T4) black fruit seed harvested from the ground, (T5) yellow fruit seed, (T6) green fruit seed. Germination percentage (%G) and germination speed index (IVG) were evaluated. It was found that seeds from black fruit picked from the tree had good germination, mostly when the tegument was removed. The germination of pinho manso seeds was influenced by the maturity stage and harvest method. It was found that there is a significant Jatropa curcas L. seeds seedling while seeds maturate. The maximum expression of viability of Jatropha curcas L. seeds is verified in black color seeds with no integument, achieving a homogeneous germination.