Germination response of curlycup gumweed seed to oxygenated water treatment

Abstract

Seed germination in an oxygenated water bath has been shown to be effective at reducing or eliminating dormancy barriers of some native western North American plant species; however, its full utility is not known. Particularly lacking is information on the effects of oxygenated water treatments on native forbs with physiological dormancy. Curlycup gumweed (Grindelia squarrosa (Pursh) Dunal [Asteraceae]) is a commonly occurring, early seral forb that is native to arid and semi-arid habitats in the Intermountain West and is used in wildlife habitat and other rangeland planting practices. We compared germination rates and final germination percentage of curlycup gumweed collections from 5 locations in the Intermountain Region exposed to 4 germination treatments: 1) oxygenated water bath; 2) non-oxygenated water bath; 3) 90-d cold-moist stratification; and 4) a non-treated control. Germination rates and final germination percentages after 35 d in oxygenated water bath treatments were equal to or greater than those from the 90-d stratification for all 5 accessions. Seed priming in oxygenated water treatments appears to be feasible for quickly and uniformly germinating seed in a laboratory environment with the possibility of expanding the technique for field settings.