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Ecology and Epidemiology

The Fungus Geniculodendron pyriforme in Stored Sitka Spruce Seeds: Effects of Seed Extraction and Cone Collection Methods on Disease Incidence. Jack R. Sutherland, Department of Fisheries and the Environment, Canadian Forestry Service Pacific Forest Research Centre, Victoria, British Columbia, V8Z 1M5; T. A. D. Woods, Department of Fisheries and the Environment, Canadian Forestry Service Pacific Forest Research Centre, Victoria, British Columbia, V8Z 1M5. Phytopathology 68:747-750. Accepted for publication 21 October 1977. Copyright 1978 The American Phytopathological Society, 3340 Pilot Knob Road, St. Paul, MN 55121. All rights reserved.. DOI: 10.1094/Phyto-68-747.

Isolations were made to determine the incidence of the fungus Geniculodendron pyriforme in stored Sitka spruce, Picea sitchensis, seeds and the effects of seed extraction and cone collection methods on disease incidence of extracted seeds. The fungus was present in 35% of the 60 stored seedlots that were assayed; fungus incidence ranged from 0.2 to 26%. Diseased seeds occurred in seedlots collected over a 9-yr period throughout British Columbia. Fungus incidence was not related to seed collection year. Diseased seeds were present in either all or in only some cones within collections. The fungus was isolated more frequently from seeds that had been hand-extracted from cones than from seeds that had been commercially (machine) extracted. Geniculodendron pyriforme was isolated more frequently from filled than from empty seeds. More filled than empty seeds were diseased. We concluded that seed extraction procedure may affect variation in disease incidence of extracted seeds as much as does variation of diseased seeds within cones. Seeds from cones collected from the ground beneath trees yielded the fungus, but seeds from cones picked from trees did not.