Dothistroma – pine needle cast, Redband disease - Mycosphaerella pini with the asexual stage Dothistroma septosporum, or Dothistroma pini
Symptoms / species
Impact / measures
Green needles of various age with several red brown or brown cross bands, reaching about 1 mm in size, diffusely bordered; later in the bands black dots fruiting bodies) and a tinge of brick-red stain or the whole band brick-red; yellowing of needles and premature loss of needles. A recently discribed new species (Dothistroma pini), occurring in the USA as well as in Europe and New Zealand, doesn't differ morphologically from Dothistroma septosporum, thus requiring a laboratory for proper diagnosis.
The disease can be mistaken for Brown spot-disease (Lecanosticta-needle cast) – here only brown cross bands without any red tinge;
Affected tree species
The disease may affect various species of Pinus as well as spruces; in Austria it is mostly common on Austrian Black Pine (Pinus nigra); repeated infections may lead to loss in increment and may weaken the trees predisposing them to other damaging agents. The disease is commonly endangering only young plants, though in other European countries and other pine species it may cause decline of adult stands (UK). The two species D.pini and D.septosporum cannot be identified on the basis of morphological features and they show the same symptoms on the needles. D.pini is more rare in Europe than D.septosporum. Further information (in German): Gehölzkrankheiten in Wort und Bild (TUM Weihenstephan).
Curative measures Density of stands, high air humidity and light deficiency favor this disease. Therefore, pines should only be planted not too densily on dryer and well aeriated sites; a fungicide treatment is recommended only for young plants in nurseries (see official register of Plant Protection).
Dothistroma-pine needle cast – symptoms on Pinus mugo