Heading stage (jointing-flowering stage): nutrition and reproductive growth go hand in hand, 25-35 days for spring corn and 20-30 days for summer corn;
Flowering stage (flowering-maturity stage): reproductive growth is dominant, with 45-50 days for spring corn and 30-40-50 days for early, middle and late maturing varieties of summer corn.
Among them, the sowing date of spring corn in Huanghuaihai area is from early April to late April, and that of summer corn is June 10-25. The specific time of the above stages is calculated according to the sowing time.