STUDIES ON SEED DORMANCY, PLANT DEVELOPMENT, AND CHEMICAL CONTROL OF TARTARY BUCKWHEAT (FAGOPYRUM TATARICUM (L.) GAERTN.).: I. SEED DORMANCY

Abstract

Effects of various physical, chemical, and storage treatments on dormancy of seeds of the noxious weed Tartary buckwheat (Fagopyrum tataricum) were studied. The dormancy is apparently not caused by any one single factor, such as impermeability of the seed coat to water suggested by earlier work. The seed coat did not prevent the entry of water into dormant seeds. Complete removal of both pericarp and seed coat resulted in a small increase in percentage germination of fresh seeds. There was no evidence of the presence of a growth-inhibiting substance. Chemical treatments were not effective in overcoming dormancy. Gibberellin improved the germination of partially after-ripened seeds, but not of fully dormant seeds. Newly mature seeds planted in the field immediately after collection failed to produce seedlings during that year. Similar seeds lost their dormancy in approximately 6 months during dry refrigeration at 2°–3 °C, and in 4–5 weeks during dry storage at room temperature. Higher temperatures accelerated the process of after-ripening, to a maximum at approximately 80 °C. Fully dormant seeds exposed to this temperature for 24–48 hours were able to germinate immediately afterwards. Relationships between moisture content, temperature, and germination are discussed.