Epidemiology and management of Pine Pitch Canker disease in Europe - a review.
Fusarium circinatum is an ascomycete fungus that causes Pine Pitch Canker (PPC) of pines. The disease is causing damages in forests and nurseries all around the world. In Europe, is present in northern Spain, and also has been detected in Portugal, France and Italy. Fusarium circinatum seems to require fresh wounds on trees as infection court. Notwithstanding, the susceptibility of these wounds to infection could decrease significantly with wound age. Fusarium circinatum has been reported to be phoretically associated with P. pubescens in California. In northern Spain, T. piniperda is a major candidate for being an effective vector of F. circinatum due to the maturation feeding it practices in the crowns of healthy pines and subsequent overwintering. At present there are no means of controlling PPC disease in adult trees in forest or plantations. However, given the seedborne character of F. circinatum, some encouraging results have been obtained by the use of different strategies to reduce the presence of the pathogen in pine seeds. For example hot water treatments (51-52°C for 30 min) were found effective in reducing F. circinatum contamination in seeds. Endophytic species which do not cause any damage that could be used for biological control of Fusarium spp., have been reported related to pitch canker diseased in P. radiata trees. The use of mycoviruses to control fungal diseases of plants could be a promising method when the genetic diversity of the populations of the pathogen is low, for example, when the introduction of the fungus in a region is recent or when sexual reproduction is absent as occurs in PPC. Recently, three different strains of mycoviruses co-infecting a Spanish isolate of F. circinatum were found and characterized. More studies are essential to prevent the rapid spread of the disease from southern to northern Europe.