Nineteen species of weed seeds collected near Edmonton during -1957 a.ndf ot 1958 rvere tested periodically for their germination percentage with or without treatmeuts with gibberellin. Nlost of the untreated samples rvere completely dormant under conditions of the test at harvest time and the rnajority of the dorrnant species remained so during a storage period of 6 months at 3" C' + 0.5'. Gibberellin treatments of up to 500 p.p.ir. in the medium, or of tlp-to 2,000 p.p.m. as a 24-hour

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... <ing treatment, rvere without_lPpreciable effect irn most of the dormant species. The chemical had a significant effect in overcoming dormancy of some, but not all, samplcs of wild oats. -Dormant seeds of l'l'ildhustard and stinku'leed were very sensitive to gibberellin treatments, while hemp nettle and blue bur shou-ed a smaller respolse. -Differences in results betr,veen different lots of certzrin sDecies emphasize the variable complexity of conditions which at a given tin're may or may not be responsive to gibberellin in initiating or accelerating the process of germination.