EFFECTS OF PRIMING ON THE GERMINATION OF VALERIANELLA OLITORIA SEEDS IN RELATION WITH TEMPERATURE AND OXYGEN

Lamb’s lettuce (Valerianella olitoria L.) seeds germinate much better at relatively low temperatures (5° to 20°C) than at temperatures above 20°C. However, their sensitivity to high temperatures depends on cultivars and seed batches.
The thermal optimum is c. 15°–20°C. Lower temperatures slow down germination, and reveal seed heterogeneity and differences between batches.
The germination of lamb’s lettuce seeds is also very sensitive to oxygen deprivation.

Presoaking of seeds in water greatly improves the percentage and the rate of germination at suboptimal temperatures or in hypoxia.
This stimulatory effect of presoaking persists after redrying and during subsequent storage for at least 2 months.
However, presoaked seeds deteriorate faster during storage than untreated seeds.

These results allow a better understanding of the causes of poor field emergence under unfavourable sowing conditions (too low or too high temperatures, or soils with excess of water), and lead to a recommendation of presoaking for improvement of lamb’s lettuce seed quality.

VI Symposium on the Timing of Field Production of Vegetables

F. Corbineau, D. Côme

https://doi.org/10.17660/ActaHortic.1990.267.24