Effects of photoperiod and temperature on flowering of twelve Stylosanthes species

Abstract

The flowering of accessions from 12 Stylosanthes species was studied in two controlled environment experiments and a glasshouse experiment. In controlled environments photoperiod exerted a strong control over flowering with short day, day neutral and long day responses being recognized. High temperatures generally delayed flowering, increased the node of first flower and reduced the number of inflorescences, but acted as a modifier only of the basic control exerted by photoperiod. With natural photoperiods in the glasshouse, flowering responses were generally consistent with the photoperiod responses observed in controlled environments. The climatic adaptation of Stylosanthes species is discussed in relation to the alternative reproductive strategies of the photoperiod response types.