The phenology of the tree is only represented by 4 stages:
- leaves expension end
- leaves fall
Time of budding is characterized by a thermal time, the duration of foliar expansion is fixed, and leaf fall occurs when the mean temperature over the last X days goes below a threshold. All these parameters are fixed for each tree species.
For the crop, the key steps of development are
- flowering (which stops or doesn’t stop vegetative development depending on the crop)
The development is controled by thermal time, modulated, depending on the species, by photoperiod and/or periods of cold, for example winter cereals need a period of cold to trigger flowering.