Horticultural Science (Mar 2006)
Sphaeropsis tip blight disease of Austrian pine in urban greenery
Abstract
An extent of the damage of Austrian pine trees was evaluated in urban greenery in selected sites in Slovak Republic during the years 2004-2005. Fungi Sphaeropsis sapinea (Fr.: Fr.) Dyko & B. Sutton (syn. Diplodia pinea (Desm.) J. Kickx fil) and Pestalotia sp. were diagnosed on all observed trees. Symptoms of the disease were recorded. S. sapinea was isolated successfully from needles and from cone scales. The growth rate of hyphae of mycelium and the mean daily growth were evaluated on three types of cultivated media at different temperatures. The highest mean daily growth of mycelium was recorded on maltose agar at 25°C after 24 hours of cultivation (31.7 mm). Conidia of S. sapinea and Pestalotia sp. on water agar began to germinate after 3 and 2 hours, respectively. After 6 hours the mean germination rate of conidia of S. sapinea was 81.75% (from cone) and 89.3% (from needles); for Pestalotia it was 88.5%.
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