A laboratory bioassay was conducted to describe the effects of cold stratification and solid matrix priming (SMP®) on the germination response of common lambsquarters and Pennsylvania smartweed seeds. Treating seeds of common lambsquarters with a combination of cold stratification and SMP resulted in 78% germination compared with 13% in control seeds. Analogous treatments of Pennsylvania smartweed seeds resulted in 22% germination compared with 1% for control. Improved germination of common lambsquarters and Pennsylvania smartweed seeds suggested that the combination of cold stratification and SMP treatments have potential for improving seed germination in other weed species that exhibit high levels of seed dormancy.

Nomenclature: Common lambsquarters, Chenopodium album L. #³ CHEAL; Pennsylvania smartweed, Polygonum pensylvanicum L. # POLPY.

Additional index words: Seeds, scarification, stratification, sulfuric acid, potassium hydroxide.

Abbreviations: H₂SO₄, sulfuric acid; KOH, potassium hydroxide; SMP, solid matrix priming.