The tetrazolium test is a quick and accurate method for estimating seed viability and vigor. This research had the objective of standardizing the preparation methods for castor bean seeds (Ricinus communis L.) to evaluate the physiological potential by the tetrazolium test. The evaluated seed preparation methods were: longitudinal cut through the middle of the seed coat, endosperm and embryo; longitudinal and diagonal cut without reaching the embryo; seed coat removal; seed coat removal with longitudinal cut through the middle of the endosperm and embryo; and seed coat removal with longitudinal cut parallel to the cotyledons through the middle of the endosperm and embryo. Before carrying out the preparation methods, the seeds were preconditioned between moist paper towels for 18 hours at 30ºC, and after preparation, the seeds were immersed in tetrazolium solution at 0.5% concentration and then placed in a dark chamber at 35ºC for the staining development. The staining uniformity was evaluated after each preparation method by comparing the methods. It was concluded that the best seed preparation method was coat removal with a lengthwise longitudinal cut, through the middle of the endosperm and embryo.
viability; methodology; seed coat
