Flowering control of Ixodia achillaeoides

Ixodia achillaeoides, a native of south Australia, is a potentially excellent cut flower that can be used in floral arrangements. The plant was found to require relatively low temperatures for flowering (< 17°C). Long days reduced the time to flower initiation and sped up development. However, under these conditions, flower initiation occurred only on terminal shoots, while axillary shoots did not develop and remained vegetative. Under both natural short days (starting from October) and controlled short days, flowering time was delayed, but both lateral and terminal shoots developed and bloomed and thus many more flowers were formed. Growing ixodia plants first under short days and then under long days decreased time to flowering but reduced the number of flowers as compared with continuous short days. When plants were first grown under long days and then under short days, flower initiation occurred earlier (as compared with continuous short days), but not anthesis. The number of flowers formed with this treatment was similar to that found under continuous short days.