Relationship of Base Temperature to Development of Spring Wheat

SUMMARY 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.