Effects of pre-sowing treatments on Jatropha curcas seed germination and seedling growth.

This study aimed to investigate the effects of different pre-sowing treatments on Jatropha curcas seed germination rate and seedling early growth. Growth and vigour of the seedlings was assessed through the measurements of growth parameters, in order to identify the best pre-sowing treatment, which guarantees both the highest seed germination rate and the best development and growth of the seedlings. J. curcas seeds of the 'Indian' cultivar were collected in Tamale region (Ghana) and subjected to five different pre-sowing treatments: i) control; ii) soaking in 30°C water for 24 h; iii) hammer shell cracking; iv) warm stratification at 37°C for 24 h; v) hammer shell cracking plus warm stratification at 37°C for 24 h. Amongst the sixteen indices considered in the experiment (six germination indices and ten growth rate indices), results revealed that the tested pre-sowing treatments influenced much more seed germination than seedling growth. Shell cracking treatment enhanced seed germination and warm stratification promoted emergence rate and seedling growth as compared to the other tested treatments.