Posición de la umbela, vernalización, ácido giberélico y fecha de plantación en la germinación de zanahoria

the objective of this study was to determine the effect of planting date, vernalization and conditioning with giberelic acid of three levels in the seed stalk on the seed germination of carrot root (daucus carota l.). the study was carried out at the instituto tecnologico de roque experimental station at celaya, guanajuato, mexico. carrot roots of cv. nantes were vernalized at 4 °c during 0, 20 and 40 days. subsecuently, were conditioned with 50, 100 and 150 ppm of giberelic acid and planted on february 22, march 4 and march 22, 2003. seed was harvested at 180 days after planting from the first, second and third umbel level and seed germination determinated by standard procedures. a complete random block design arranged in subdivided plots and four replications was used. results showed 86% germination in seeds from the first umbel level planted on february 22 with vernalization. no difference was observed in seeds from the second umbel level vernalized during 40 days and the control, with germination of 81.67 and 81.97%, respectively. seeds from the third umbel level treated with 100 ppm of giberelic acid showed 78% of germination. in spite of the statistical differences observed among the plantig date, vernalization and conditioning with giberelic acid, these differences are not agronomically relevant.