Characterisation of bract browning and the effect of shade on browning in waratah (Telopea spp., Proteaceae) cultivars ‘Fire and Brimstone’, ‘Olympic Flame’ and ‘Wirrimbirra White’

This paper describes the appearance, timing and severity of bract browning in the New South Wales waratah [Telopea speciosissima (Smith) R. Br., family Proteaceae] and its hybrids with other Telopea species. Descriptions of bract types and maturity stages were developed during the course of the research. Browning tended to occur on bract tips, and to a lesser extent on bract margins or in patches. Bract browning generally occurred in the 6–8 weeks prior to flower maturity (perianth opening), coinciding with rapid bract and flower expansion. Further experiments revealed that shading (50% shade cloth) significantly reduced bract browning in potted and commercially grown waratahs of cultivars ‘Fire and Brimstone’, ‘Olympic Flame’ and ‘Wirrimbirra White’.