F. Corbineau, D. Côme
Endive (Cichorium intybus L.) seeds do not show any dormancy. They germinate in a large range of temperatures (5° to 30°C), but the thermal optimum is c. 25°–30°C. At low temperatures (5° to 12°C) germination is slowed down (longer lag time, reduced germination rate). Also seed heterogeneity and differences between batches are revealed, which are not observed at the optimal temperature. Thus, germination tests carried out at 10° or 12°C allow a better evaluation of seed quality and field emergence than usual tests.

Seed quality depends on the genetic characteristics of the plants, but it is also strongly affected by the conditions of seed development on the mother plants and by storage conditions after harvest. In the different hybrids studied, the poor germination observed in some batches was due to black seeds which are not mature enough at harvest time and contain an incompletely developed embryo. Seeds with a lighter colour always germinate very well owing to the fact that their maturation is faster and therefore more complete at harvest.

Seeds remain viable for more than one year when stored dry in different conditions. However, during storage they become more sensitive to subsequent low germination temperatures.

The results obtained allow us to propose some practices for evaluating or improving the quality of Cichorium intybus seeds : sorting of seeds according to colour; germination tests at suboptimal temperature; harvesting at a suitable developmental stage.

Corbineau, F. and Côme, D. (1990). GERMINABILITY AND QUALITY OF CICHORIUM INTYBUS L. SEEDS. Acta Hortic. 267, 183-190
DOI: 10.17660/ActaHortic.1990.267.23

Acta Horticulturae