Seedling emergence, seedling biomass, and root lengths of Russian wild ryegrass seedlings were analyzed with respect to seed source, seed mass, seeding depth, and harvest. Multiple regression models containing these factors were statistically significant predictors of the log-transformed seedling biomass and root length data (DF = 9, F-biomass = 1763.67, F-root = 949.33, and P < 0.0001 for both variables). The effects of seed mass, seeding depth, and harvest were significantly related to the dependent measures while the effect of seed source was not significant. Seedling emergence from soboptimal seeding depths was significantly greater for heavy seeds than for light seeds (chi(2) 14.076, DF = 7, P < 0.0001).