Lecanosticta-needle cast, Brown spot disease of pines - Lecanosticta acicola
Symptoms / species
Impact / measures
Yellowing of needles of all ages, needles with dark, diffuse cross bands and stripes, in which pustules develop, which often show a tinge of green (hand lens); often only the distal half of the needle is discolored, the proximal parts remaining green for a while (possibility of errors: Swedish needle cast of pine); often needles shorter than usual, never reddish colors in or around the bands (possibility of errors: Dothistroma-needle blight)
Affected tree species
Infestations lasting several years lead to intense crown thinning, reduction in increment, slight shott dieback and weakening of the plant, even of older trees; endangering the life only of young pines; Attacks numerous pine species, in Europe mainly Scots pine and Mountain pine (P.mugo as well as P.uncinata); in America widespread; in Europe only restricted spread in several countries (also Austria); preferring warm and very humid climate, thus slow development in Austria on sites with high precipitation.
Curative measures Quarantine-organism, therefore obligation to report observations to the Federal Plant Protection Service! Removal (burning) of all infected plants; chemical treatment without any effect.
Mycosphaerella dearnessii: browning of needles, partly only the distal half of the needle affected
Mycosphaerella dearnessii: browning of needes
Mycosphaerella dearnessii: spore tufts with emerging conidia
Mycosphaerella dearnessii: spore tufts in brown cross bands