The acquisition of carrot (Daucus carota L.) seeds with high quality is restricted to the high heterogeneity at physiological maturity, because it produces seeds at different times and sizes. The classification of carrot seed by size can be a good alternative for improving the physiological quality. To differentiate seed lots by physiological quality, and identify tests that provide an estimate the performance of seed classified by size, it was developed an experiment with three seed lots of carrot cultivars 'Alvorada' and 'Brasília'. It was obtained six different treatments, given by combination of the two cultivars, which had medium, large and extra large size. At the cultivars 'Alvorada' and 'Brasilia', although there is no influence of seed size on germination percentage, shoot length and total seedling, there was a significant difference, in dry weight seedlings, seed weight, and root length. This shows that this variable was most sensitive to differentiate the existing lots. So, lots with small seeds showed inferiority in physiological quality in relation to larger seeds, justifying the classification of seeds by size.
size of seed; Daucus carota L; heterogeneity in physiological maturity
