Temperature controls rates of plant development, but not necessarily critical ontogenetic
phase changes such as induction of bud-break, flowering or leaf senescence,
which may be determined by photoperiod. Commonly, it is the speed at which plants
and their organs pass through developmental phases, which depends on temperature.
For instance, a higher temperature may shorten the period of grain filling in wheat
(Wheeler et al., 1996). So, temperature effects interact with other environmental and
internal drivers of development. Temperatures, low ones in particular, may serve as
a signal which alone or together with photoperiod set the receptivity of plants to
the gradual direct influences of temperature on metabolism and growth as described
above.