The phyllochron is the intervening period between the sequential emergence of leaves on the main stem of a plant, also rendered as leaf appearance−1.
This measurement is used by botanists and agronomists to describe the growth and development of plants, especially cereals.
[3] Increases in phyllochron in cereals correlates with growing degree units in a slightly curvilinear fashion.
[4] In all cultivars of cereals, fluctuations in temperature are the primary factor that affects the length of the phyllochron.
[3] Less important secondary factors emerge in a number of different and sometimes contradictory studies on phyllochron response to variation in light, CO2 level, irrigation, nitrogen availability, salinity, soil properties, planting depth, planting time, and genotype.