|
Symptoms
| |
1.Dieback of shoots and twigs. 2. Simultaneous death of crown parts; needles turn yellow to red-brown. On pines of all ages. In late stages needles turn pale grey, but remain on the dry twigs for a time. Black, roundish fruiting bodies, 1mm in size, develop in the dead bark of twigs, not always breaking through the epidermis (cutting into the bark necessary for diagnosis).
|
|
Impact
| |
In Austria, Sphaeropsis sapinea occurs mainly on Austrian Black pines in areas with pannonic climate: here it is at present the main microfungus causing dieback and crown decline of pine: outbreaks are usually following long and extraordinary dry periods in summer, especially, if the preceding spring was characterized by high amounts of precipitation. Rainy springs result in long shoots, which, stressed by drought in summer, are easily infected by the fungus. Shoot dieback alone is a sign of only moderate stress, intense stress often causes decline of the whole crown, since in this case the fungus infects at the base of branches. Further information (in German): Gehölzkrankheiten in Wort und Bild (TUM Weihenstephan).
|
|
Control
| |
In urban and ornamental trees a balanced water supply should be maintained. In young forest stands a thinning can enhance the vitality of healthy of only slightly infected pines. In addition, thinning as a hygienic measure can prevent from the establishment of secondary bark invaders.
|
| Hosts |
|
Pine;
|
| Affected plant parts
| |
Needle;
Shoot/Twig/Branch;
Stem;
|
