The vegetation period of maize is characterized by the FAO index, which links a hybrid to its requirement for the sum of effective temperatures above +10°C to achieve physiological grain maturity.
In the reference
386
varieties
crop Maize,
where this is mentioned in the description.
In maize agronomy, the duration of the vegetation period is determined not by calendar days, but by the FAO index — a relative measure of earliness. It reflects the plant's requirement for a sum of active or effective temperatures to complete its developmental cycle, which ends with the appearance of the 'black layer' at the base of the grain.
Hybrids are classified on the FAO scale from 100 to 600+, with each group corresponding to specific ranges of temperature sums and estimated maturity times. Choosing a hybrid with an appropriate index is critical for climate adaptation, as the high heat requirement of late-maturing varieties directly affects their yield, grain moisture loss rate, and the risk of failure to reach maturity before the onset of cold weather.
General information about the subject — on the page
Vegetation period.
Selection based on the description text, not on official evaluation: these data are absent from registers. For specific variety details, please refer to its profile.