Stages of maturation of the fruit on germination and oil content in seeds of Jatropha curcas Lin

Abstract

Jatropha curcas Linn., known as physic nut, is a plant that has oil content between 35 and 38%, being used as an alternative for producing biodiesel. However, this culture has uneven fruiting, which discourages the harvest period. This study aimed to relate the color of the seeds during fruit maturation and germination characteristics with the oil concentration, confirming the best time for harvest. Using the Munsell color chart the seeds were classified into four stages: VC (light seeds of unripe fruits), VE (dark seeds of unripe fruits), A (seeds of fruits attached to the tree) and C (seeds to the ground). It was conducted the germination test, moisture, dry matter and oil content. The seeds of fruits that were attached to the tree (level A) obtained better results in test of germination, about 25% because they had higher dry matter (90.51%) and lower water content (9.49%). They also had the largest concentration of oil, which was 47.36% (almond), and therefore, the best stage for harvesting. The light seeds of unripe fruits (VC), did not obtain satisfactory germination (1.25%), indicating that the color of the fruits can be a parameter for physiological maturity of Jatropha curcas Linn.