Abstract:
The success of the forestry industry in the world and particularly the Southern
hemisphere can be attributed to the choice of fast and easy-growing exotic pine and
eucalypt tree species, which have been planted separated from their natural enemies.
In South Africa, species of Pinus, Eucalyptus and an Acacia species have been planted
to sustain commercial forestry. This industry in South Africa is at risk, however, because
of pest and pathogen movement around the world. Various species of Fusarium
represent some of the most serious threats to the forestry industry. The genus includes
a large number of species, many of which are important plant pathogens with host
ranges that include species in Pinus, Eucalyptus and Acacia. An important and well
known example in South African commercial forestry is Fusarium circinatum, which
causes the disease known as pitch canker. Research on this pathogen has advanced
our understanding and ability to identify the pathogen rapidly and to establish measures
that will contain its spread. Identification of pathogens such as species of Fusarium
represents a first step towards developing control measures. Diseases caused by
emerging pathogens are becoming more complex due to exacerbating factors such as
the effect that climate change might have on host-pathogen interactions. Understanding
of all these factors should contribute to an enhanced capacity to protect forest
plantations in the future.