a1 Instituto de Investigaciones Agropecuarias, Estación Experimental Quilamapu, Chillán
a2 Instituto de Investigaciones Agropecuarias, Estación Experimental La Platina, Santiago, Chile
The base temperature and thermal time for different development stages of spring wheat cultivars were calculated using a linear relation between the rate of development and the mean temperature. The results show that germination, emergence, tillering and leaf elongation (the vegetative phase) have a base temperature around 2°C but the elongation of the culm and the reproductive phase (tillering-maturity) have a base temperature over 6°C. A general model to describe the time to maturity of spring wheats, which takes account of these different phases, is proposed.
(Accepted March 19 1986)