Seed production and germination in Agrostemma githago

Selected reproductive characteristics of Agrostemma githago (capsule number per plant, seed number per capsule, seed weight) are presented . Plants were grown in three different situations, i.e. (1) garden bed, (2) rye field and (3) winter wheat field in central Bohemia. Among-site differences were found in all the characteristics studied. Plants grown under garden conditions exhibited significantly higher values than those from both fields. The plants grown with rye produced fewer capsules with more and heavier seeds than those growing in the wheat field. Germination rate of seeds from the wheat field was significantly lower (about 10 %). Most of the freshly harvested seeds (74-87 %) germinated within 4 days. The germination was slower in older seeds, especially those stored for more than 30 weeks, but the total numbers of germinated seeds were similar in all age groups (85-95 %). The seed viability was high even 3 years after the harvest and reached 85 %.