Q. Has anyone answered the problem of splitting? A: A theory was prepared last year, but not enough data was collected to give definite proof. The idea was that in the spring when light is increasing there is a sudden increase of light some time in April. All the calyxes formed before this time are small. The petals formed with the sudden increase in light are large. With large petals in a small,calyx, splitting occurs. This accounts for the sudden appearance of splitting and also for the comparatively short duration of splitting. Jake Miller: They also feel that splitting is associated with calyx size, and are trying to breed larger sized calyxes.
Source: • New York State Flower Growers Incorporated, Bulletin # 124