ABSTRACT
The importance of light for flower development has long been recognized. This chapter provides the classification according to photoperiodic response type that was essentially based upon two different developmental criteria: the occurrence or absence of flowers reaching anthesis and the rate of flower development as measured by the time from initiation to anthesis. It focuses on more general aspects of flower development, such as rate of development and abortion. Proliferous flowers have been found in several species grown in noninductive or just subcritical daylengths. The influence of daylength on sex expression was first recognized by J. Tournois. Daylength may act independently but also in conjunction with irradiance since both contribute to the daily light integral. Inflorescence development is frequently a function of light integral and/or irradiance, both of which vary concurrently in greenhouse and field conditions. Abortion of flowers or inflorescences seems to be one of the main light-affected problem in several species including roses, Bougainvillea, and some bulbous crops.
