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’

The function of regreening in yellow femaleLeucadendron(Proteaceae)

“…It appears that the browning encountered in exposed Leucadendron cones likens the bract browning reported to occur in waratahs (Telopea spp.) in that the bracts exposed to full sunlight showed significantly more browning (McConchie et al 2005, Martyn et al 2007. The term sunburn browning is advocated to describe observed cone browning.…”

Photoinhibition and changes in pigments associated with bract browning in waratahs (Telopeaspp., Proteaceae)

“…Plants were shaded from bud-swelling in mid-August 2002, and bract browning was monitored every week until mid-September. General cultivation details for the two sites are described in Martyn et al (2007a).…”

“…Buds developed over Autumn and Winter, with bud swelling and rapid development occurring in late Winter and early Spring (August to September depending on cultivar and location ;Martyn et al 2007a). Flower maturation occurred during Spring (September -October).…”

“…However, the bracts surrounding the inflorescence are often affected by browning, leading to a reduction in cutflower quality and this reduces their market value and potential for export. Bract browning in waratahs generally occurs 6 -8 weeks prior to harvest, and is more severe when plants are grown in full sun (Martyn et al, 2007a). Recent experimental evidence (Martyn et al, 2007a) confirmed anecdotal evidence that protection and shading produced higher quality waratah flowers by reducing bract browning (Offord, 1996;Nixon, 1997).…”

“…Bract browning in waratahs generally occurs 6 -8 weeks prior to harvest, and is more severe when plants are grown in full sun (Martyn et al, 2007a). Recent experimental evidence (Martyn et al, 2007a) confirmed anecdotal evidence that protection and shading produced higher quality waratah flowers by reducing bract browning (Offord, 1996;Nixon, 1997). The physiological cause of this browning, and its reduction under shade (Offord, 1996;Nixon, 1997), have not been investigated in detail, prior to this study.…”