Spatial Distribution of Synchytrium endobioticum, the Cause of Potato Wart Disease, in Field Soil. M. C. Hampson, Research Scientist, Research Centre, Agriculture and Agri-Food Canada, PO. Box 37, Mount Pearl, Newfoundland A 1N 2C1. J. W. Coombes, Technician, Research Centre, Agriculture and Agri-Food Canada, PO. Box 37, Mount Pearl, Newfoundland A 1N 2C1. Plant Dis. 80:1006-1010. Accepted for publication 13 May 1996. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1996. DOI: 10.1094/PD-80-1006.

The spatial distribution of resting spores of Synchytrium endobioticum was studied in three extents in two fields. The extents were sampled with a device that removed blocks of soil. Two extents were divided into three sections, 6 m apart, and one extent retained as a single block. The extents were divided into grains that measured either 20 cm2 x 5 cm or 5 cm2 x 5 cm, and the spore population of each grain estimated. The data were mapped, and subjected to analysis using Lloyd’s Index of Patchiness. There were differing levels of spore aggregation across the grains. No particular pattern of aggregation emerged; the aggregates assumed random patterns of distribution. Biological, edaphic, and cultural dispersal mechanisms were considered, and it was concluded that the pattern of distribution likely followed gall production (biological dispersal).

Keyword(s): contour, sampling, soilborne