1974 Volume 1974 Issue 17 Pages 24-28
1) A month of chilling of Chenopodium album seeds on moist filter paper at 10°C gave about the same percentage germination as those after 6-7.5 months on moist filter paper and in soil at 5°C. Dormancy-awakening also progressed slightly on moist filter paper at 1°C, while the dry storages lasting 7.5 months at 5°C and 25°C were not effective in dormancy-breaking.
2) In dormancy-breaking of Echinochloa crusgalli var. praticola seeds, the 2 months dry storage at 25°C was as effective as the 2 months treatment on moist filter paper at 10°C. Placing at alternating temperatures in white fluorescent light, the seeds which had been chilled in moist filter paper at 1°C and 5°C for 2 months increased germination to 93 percent, but incubating at 20°C in dark, the same treatment seeds came up to only 1 percent. The dormancy, however, was not broken by the dry storage at 5°C for 7.5 months. It was found that considerable number of seeds lost their viability in soil at 5°C after 6 months.
3) In seeds of Polygonum lapathifolium, the two months chilling treatments on moist filter paper at 1°C, 5°C and in soil at 5°C were all equally effective in breaking the dormancy, but on moist filter paper at 10°C few seeds awaked after 6.5 months. After-ripening proceeded gradually under the dry starages at 5°C and 25°C, with the faster rate at 5°C.
4) The freezing at -11°C was not effective in breaking the dormancy of the seeds of the 3 weed species.
