Paulownia trees are indigenous to China, where they are found in all regions from the sub-tropical south, to the plains and mountainous areas in the north. In Australia, a number of Paulownia plantations have been established in recent years as the timber is a valuable resource with strong export potential. The main species grown are P. fortunei and P. tomentosa.
In Western Australia, major plantations have been established to the north of Perth, in a Mediterranean environment with irrigation and fertigation over the summer months. At some sites the trees are subject to strong winds that can cause significant physical damage to the large leaves, and sunscald also has a major impact on tree growth.
In addition to abiotic factors affecting the health of the trees, foliar diseases are also present. Alternaria blight (1) and a phytoplasma-associated disease (2) have been reported, and other pathogens are regularly being identified. Here we outline some of the major findings from research being conducted on Alternaria blight of Paulownia in Western Australia