Abstract:
Fusarium circinatum, the causal agent of pitch canker of mature pines and root/collar rot of pine seedlings/cuttings, has resulted
in large-scale losses to pine forestry in various parts of the world. The disease caused by this fungus is now regarded as one of
the most important threats to pine plantations by a pathogen. Fusarium circinatum was first discovered in South Africa in 1990
where it infected Pinus patula seedlings in a nursery. Subsequently, the pathogen spread to pine nurseries in all other parts
of the country, where it affects several Pinus species. Fusarium circinatum then appeared in the field where it has resulted
in large-scale mortality of mostly young P. patula seedlings after planting. Pitch canker first appeared on mature P. radiata
in 2006 and sporadic outbreaks of the disease have occurred subsequently on this species and on P. greggii in the western,
southern and north-eastern Cape. Pinus patula is the most important softwood species grown in South Africa, comprising 50%
of all softwoods planted, and is highly susceptible to F. circinatum. The pathogen, therefore, poses a potentially devastating
threat to the future sustainability of the South African softwood industry. Strategic measures to minimise further spread are
urgently needed. This review presents an overview of the impact that F. circinatum has had on South African forestry, and it
considers the long-term prospects for pine forestry in the country as this relates to the presence of the pitch canker fungus.
