| Reestablishment of spiny hopsage (Grayia spinosa (Hook.) Moq.) where depleted or lost on shrub steppe sites can improve forage, plant cover, and soil stabilization. The objectives of this study were to: (1) determine direct-seeding requirements; (2) develop optimum germination pretreatments; and (3) examine dormancy mechanisms in spiny hopsage fruits and seeds.;The effects of seed source, planting date, and site preparation method on seed germination and seedling establishment (SE) were examined at Birds of Prey and Reynolds Creek in southwestern Idaho. Three seed sources were planted on rough or compact seedbeds on 4 dates in 1986-87 and 3 dates in 1987-88. Exposure to cool-moist environments improved spring SE from early fall (EF) and late fall (LF) plantings. Few seedlings emerged from early (ESp) or late spring (LSp) plantings. SE was low at 1 site in 1986-87 and at both sites in 1987-88, probably due to lack of precipitation. For the successful 1986-87 planting, seedling density was greater on rough compared to compact seedbeds in April and May, possibly due to improve microclimate conditions. Growth rate varied among seed sources, but seedlings developed a deep taproot (mean length 266 mm) with few lateral roots the first season.;Seeds were planted on 3 dates in 1986-87 and 1987-88, and nylon bags containing seeds were planted on 4 dates each year to study microenvironment effects on germination (G), germination rate (GR), and SE. Bags were recovered on subsequent planting dates, and seeds were tested for moisture content, viability, G, and GR. In 1987-88 with low precipitation, seedlings established only from LF plantings (;Utricles and seeds responded to stratification for 60 days at 3-5... |
