Effects of seed age and seeding depth on growth of Stipa lagascae R. & Sch. seedlings

Native grass species are being considered in the restoration of degraded rangelands in Tunisia due to the failure of introduced species to adapt to the ecological constraints of the region. The objective of this study was to determine the effects of seed age and seedling depth on emergence and seedling vigor of Stipa lagascae, a perennial bunchgrass that is native to the region and shows promise as a species for restoration purposes. Total emergence percentage of seedlings and the coefficient of rate of emergence (CRE), the seedling vigour as well as above and below-ground biomass were measured. Younger seeds had higher emergence rates than older seeds. However, seed age did not affect variables associated with seedling vigour. Seeding depth significantly affected all parameters tested. A seeding depth of 4–6 cm was found to be optimal.