Seed dormancy and germination of Shaggy soldier (Galinsoga ciliata Blake.) and Common lambsquarter (Chenopodium album L.)

Laboratory experiments were carried out with seeds of Galinsoga ciliata and Chenopodium album in 1998, 2000 and 2001. The study involved germination of non-dormant seeds in the light and the dark at 5-30°C, the germination energy at 15, 24, and 33°C, and the primary dormancy of seeds matured during the period from July to October. Both weeds germinated better in the light compared to the dark. Seeds of G. ciliata germinated at 10-33°C. Germination exceeding 85% was recorded at 12-28°C. Ch. album germinated in a wider temperature interval (5-33°C). Maximum germination (75%) was obtained at 18°C. A very high germination energy of G. ciliata seeds was found at 24°C. At this temperature, 89% of seeds germinated during the second and third day of the germination test. Seeds of Ch. album had a low germination energy at 15 and 24°C. The germination energy was high only at 33°C, however, the total germination reached at this temperature was only 26.5%. Both G. ciliata and Ch. album formed primary dormant seeds during all three testing years. The length of primary dormancy varied from 10 to 100 days depending on the date of ripening and on the year. The longest primary dormancy was found with early ripened seeds (July and August).