GERMINATION RATE AND EMERGENCE SUCCESS IN BLUEBUNCH WHEATGRASS

Development of plant materials adapted to the demands of a harsh envir onment and conditions created by standard planting practices has resul ted in improved seedling establishment for some species. Bluebunch whe atgrass (Pseudoroegneria spicata [Pursh] Love) is an important native bunchgrass often planted in the Intermountain and Pacific Northwest re gions. Though cultivars have been developed, this species continues to have a reputation for weak seedlings. Forty-seven accessions of blueb unch wheatgrass collected from naturally occurring populations in 9 ge ographic regions and the cultivar 'Goldar' were evaluated for germinat ion rate, seedling emergence and growth, and seed weight. Significant differences in seed weight and germination rate at optimum (15/25-degr ees-C) and cold (1-degrees-C) temperatures were observed. Seedling eme rgence from a 4-cm depth ranged from 5 to 66%. Mean dry shoot weight 2 8 days after planting varied among accessions by a factor of 6. Simple correlations between seed weight and percentage emergence (r = 0.62) and seed weight and mean shoot weight (r = 0.63) indicate seed weight could be used as a preliminary screening test for these traits. Seed w eight was not useful in predicting germination rate. Results suggest e stablishment success may be improved through careful selection for tra its associated with seedling vigor.