Regarding adult pines, the most striking symptom of this disease is an excessive resin flow on the stem. In these flat resinous areas which often reach several meters in length, the bark is dead and red-brown. The wood below is usually not discolored. Characteristically any callusing of the lesion is missing. Because of the necrosis, crown dieback occurs followed by the death of the tree. If infection starts from the soil, a massive root rot develops and later on the whole canopy turns pale green and later yellowish and finally brown. Root rot in seedlings causes unspecific wilt and death of the plant. In Douglas fir, the species affects twigs leading to unspecific dieback symptoms.
Affected tree species
Douglas fir; Fir; Larch; Pine; Spruce;
Needle; Stem; Shoot/Twig/Branch; Root;
Up to now pitch canker was limited in Europe to Spain and Portugal, where the disease affects pines leading to decline of forests. Since the pathogen is favored by warm temperatures (Mediterranean climate), the actual climate change could turn large areas of Central Europe suitable for establishment of this disease. The risk for a spread is high, since the pathogen can be vectored with plant stock and seeds (showing no symptoms there!). Moreover numerous insect species are able to transport spores and finally also rain and wind can function as vector. Therefore Fusarium circinatum has the highest quarantine status (Union Quarantine Pest) in Europe. Consequences are limitations of import (plant stock, wood, etc.), regular surveys to enable an early detection of new outbreaks and periodical reports. In case of outbreaks strict eradication measures are ordered.
Curative measures Curative measures are not available for F.circinatum. Avoidance of new infections/outbreaks is essential. For this the knowledge, that excessive resin flow and dieback of pines can indicate pitch canker is a primary prerequisite for the timely information of the phytosanitary service or the diagnostic lab.