Farm Forestry New Zealand
PESTS AND DISEASES OF FORESTRY IN NEW ZEALAND
Symptoms observed in September, tree age from six to fifteen years
Dothistroma needle blight occurs all year, but first appears on current foliage about December.
Needles
Brick red bands on green needles with black spots usually seen within the bands. Needles die completely and are retained. Needles may wilt, but usually wither and turn brown/grey.
Incidence and severity
General distribution, almost every tree in affected parts, but tree to tree variation is apparent.
Red needle cast occurs from April to October on trees of all ages, but generally those over 3 years old.
Needles
Oily green band, then yellow, then red. Needles detach readily. Resin blobs are sometimes seen at the needle base.
Incidence and severity
Localised/general distribution, almost every tree in affected parts of a stand.
Cyclaneusma needle cast occurs from September to November. Symptoms are seen on trees from six to twenty years.
Needles
Yellow, then gold, then brown. Needles detach very readily. No needle wilt.
Incidence and severity
Scattered individuals, up to 90% severity on very susceptible trees.
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