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.