Needle cast of Pinus radiata in New South Wales [fungal infection]
1991
Choi, D. (Commonwealth Scientific and Industrial Research Organisation, North Ryde (Australia). Div. of Biomolecular Engineering) | Simpson, J.A. (New South Wales Forestry Commission, Beecroft (Australia). Wood Technology and Forest Research Div.)
Green needles of 7-9-year-old Pinus radiata trees have been infected primarily by 2 species of fungi, Cyclaneusma minus and Lophodermium pinastri. Needles persisted on the trees for about 2 years before developing symptoms of C. minus infection during summer and autumn. Immature current year's needles were infected by both C. minus and L. pinastri before they were fully elongated. Ascospores of C. minus were released from cast needles in very large numbers in spring and most new infections occurred during this period. Infection by L. pinastri lagged behind that by C. minus by about 2 months. There was significant between-tree variation in disease levels of each of these fungi. Susceptibility to C. minus was not linked with susceptibility to L. pinastri. Nitrogen levels in P. radiata foliage and symptom expression are correlated.
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