This study was carried out to determine whether a single radicle emergence count can be used for vigour assessment and as a predictor of seedling emergence and quality in leek seed lots. The experiment was carried out on 25 leek lots with single radicle emergence counts performed after 72, 96, 120 and 144 hours of germination (20 degrees C, dark, between papers). Seedling emergence tests were carried out in a controlled climatic room (22 degrees C, 72 mu mol m(-2) second(-1) light) in peat moss. Seedling emergence percentage, mean emergence time and fresh and dry weights of the seedlings were calculated after 16 days. Each radicle emergence count was correlated with the calculated measurements. Radicle emergence count at 120 hours of germination correlated highly (r = 0.717-0.839, P < 0.001) with the seedling emergence, mean emergence time and seedling fresh and dry weight. Regression (R-2) values were 0.70, 0.65, 0.51 and 0.63, respectively, and highly significant (P < 0.001). The results indicated that the 120-hour count during germination can be used as a vigour assessment and a predictor of seedling quality in leek seed.