Effects of light and temperature on the germination and seedling vigour ofAtriplex cordobensis (Gandoger et Stuckert) seeds harvested in autumn and winter

Field showing is one of the main issues to be considered in the study of th e domestication of Atriplex cordobensis as a forage plant for semiarid regi ons. Knowledge on the factors that affect germination and seedlings vigour is essential for this stage. The purpose of this work is to evaluate the ef fects of temperature and light and their interaction with the harvest seaso n on the germination and seedlings vigour of A. cordobensis. Germination pe rcentage, G50, and dry weight of the resulting seedlings show that 8-hr pho to period and 20 degrees C were optimum germination conditions. Interaction s between light, temperature and harvest season were as important as the si ngle effects of these factors. Thus, it was seen that inhibition of germina tion by darkness was higher at higher temperatures and greater in seeds har vested in winter than in autumn. Light appears to be necessary for the init iation of germination and temperature effect shows adaptation of this speci es to local temperature regimen.