Casuarina dieback

February 2005. Casuarina equisetifolia, or South seas ironwood, is sometimes seen affected by a dieback condition in Guam. Needles on a branch turn yellow, then the branch may eventually die, and even the whole tree may die in time.

It was suggested to look at Diseases of Cultivated Crops in Pacific Island Countries by Kolher et al. (published by SPC, 1997); there is an illustrated description of Ganoderma, which can cause dieback. Phellinus noxius is also recorded on Casuarina. There are plenty of references to it on the Internet.

There is a datasheet on the CABI Crop Protection Compendium.

Experiences in Vanuatu were different. There the trees are seen growiing on an alluvial plain that has clay at 30 cm and has been totally saturated for months by continuous rain to the extent that even some of the weeds were dying, but the Casuarina just keeps on growing. They also can be found growing right on top of coral next to the sea where they continually get doused with salt water spray and appear to thrive. They tolerate cyclones as if it were a breezy day. Shame that their timber has no use!