Casuarina dieback

February 2001. In Guam, a new problem of Casuarina equisetifolia saplings was reported. The seedlings are
produced in dibble tubes in the nursery then transplanted in rows for a windbreak. Symptoms appear on seedlings that are 3-5 feet tall. Needles midway up the plant turn bright yellow, then the yellowing spreads up and down the plant while the top and bottom remains green. Whole branches later show the symptoms. It causes a vascular discoloration which is localized in the area of yellowing and the stem appears swollen. The saplings eventually die.

Breaking off the infected portion sometimes results in the death of the plant and sometimes stops the disease development, at least temporarily. We have not been able to find any oozing which might suggest a bacteria, nor have we found any fungal fruiting bodies.

PestNet members could offer no suggestions apart from the oft reported diseases, such as pink disease which causes branch dieback in Casuarina equisetifolia and other woody plants; blister bark (Trichosporium vesiculosum), which causes yellowing at an early stage; and bacterial wilt (Pseudomonas solanacearum). Are there any dark streaks in the woody tissue, which might indicate bacterial wilt.