EFFECTS OF SEED TREATMENTS ON THE SEEDLIN G EMERGENCE, GROWTH AND YIELD OF SPRING-SOWN CARROT

Carrot seeds, untreated, imbibed, primed, pregerminated and primed + p regerminated, were sown in the field on 28 March, 4 and 11 April. The effects of these presowing seed treatments on seedling emergence, subs equent growth, and yield were examined. Percentage emergence of seedli ngs from presowing-treated seeds was not improved. However, mean emerg ence times of seedlings from presowing-treated seeds were shortened co mpared to that of untreated seeds. The effect of seed treatments on em ergence time of seedlings was in the following order : primed + preger minated > primed > pregerminated > imbibed. This trend coincides with a previous finding in which plants were grown in pots under low temper ature conditions. Plant dry weight from primed + pregerminated seeds w as heaviest of all treatments at early and middle stages of growth, fo llowed by weight from primed seeds. However, plant dry weights from im bibed and pregerminated seeds were not always significantly heavier th an those from untreated seeds. In the second (4 April) sowing, mean ro ot fresh weight and percentage of number of roots at 50 g or heavier f rom prime + pregerminated and primed seeds were higher than those from other treatments or those from untreated seeds. In the third (11 Apri l) sowing, there were no significant differences in the size and yield of roots among treatments and the control. The results show that preg ermination after priming of seeds improved the yield of carrot when so wn in the spring and the temperature is still relatively cold.