BREAKING DORMANCY IN CASTOR BEAN (Ricinus communis L.) SEEDS

Biodiesel has ecological advantages that have stimulated research, both in order to obtain improved varieties with high productivity, and to optimize the process of fuel obtaining, all focused on the development of technologies to replace fossil fuels. One of the crops used for this purpose is the castor bean (Ricinus communis) but it presents a large phenotypic diversity and germination problems. In this study, 12 treatments were used to break dormancy in seeds of a native population of the region and another derived from it, mutated for breeding purposes. Refrigeration, gibberellic acid + potassium nitrate and infrared light were used. The best results (treatments 5, 9 and 11) were obtained with the combination of gibberellin + potassium nitrate, with more than 95% germination, while some treatments (cold with infrared light or washing with methanol) failed to overcome dormancy. High germination rate and good sowing are crucial for commercial purpose planting. The study of latency has important implications both physiologically and for seed quality in order to make production cost-effective and easy to handle. In conclusion, it was possible to achieve more than 85% germination in both populations.