Determination of a pre-vernalization phase in carrot cv. Flakkee

GALMARINI, C.R.; BORGO, R.; TIZIO, R.

TURRIALBA

IICA

Año: 1994 p. 140 - 142

0041-4360

The present study was conducted  to determine the presence of a pre-ver­nalization phase in carrot (Daucus carota L.) cv. Flakkee, before vernaliza­tion at low temperatures. Carrot plants and seedlings in the following phenolo­gical stages: 9 to 10, 7 to 8, 5 to 6, 3 to 4, 1 to 2 leaves and in cotyledonar stage, grown un­der long day conditions (14 hs, 280 Umol s-1 m-2) and temperatu­res ranging from 25o+1oC day and 20 + 1C night, were simultaneously exposed at low temperatures (7+1C day and 5o+1oC night) and short days (10 hs, 280 Umol s-1 m-2) during 55 days. In addition, germinating and dried seeds were also treated. Later on the plants were exposed to long days (16 hs) and 25o+1oC day and 20o+1oC night. Only those plants which were at the stage of 9 to 10 leaves at the beginning of the cold treatment bolted and flowered normally. These facts indicate that cv. Flakkee has a pre-vernalization phase which lasts until the 9 to 10-leaf stage is reached.