Physiological quality of castor seeds (Ricinus communis L.) after processing

Abstract: Castor bean seeds are the raw material used for extracting oil destined to pharmaceutical and industrial ends. The appropriate application of post-harvest technologies, such as processing, is required to ensure the production of top quality seeds. Thus, this study aimed at assessing the physiological quality of seeds from two castor bean genotypes, classified according to their specific mass and size. Castor seeds of the genotypes EVF102 and EVF103 were mechanically harvested and then classified with the aid of cylindrical sieves and a densimetric table. This procedure was conducted at the processing unit of the company Sementes Goiás LTDA [Goiás Seeds Co.]. Evaluations of seed physiological quality were carried out in the Seed Laboratory of Instituto Federal Goiano, following a completely randomized design. The testing was conducted in four replicates, in a 2 x 2 x 5 factorial scheme (two genotypes x two sizes x five specific masses). The following parameters were appraised: (a) mass of one thousand seeds; (b) germination; (c) germination speed index; (d) emergence test; (e) emergence speed index; (f) electrical conductivity; and (g) accelerated aging. Genotype EVF102 seeds sized 8 mm, as classified by the densimetric table, showed the highest physiological quality, considering the germination, germination speed index, and emergence. Seeds of the genotype EVF103, sorted by size, exhibited no difference in physiological quality.