ETIOLOGY OF A ROOT-ROT DISEASE COMPLEX OF ALSTROEMERIA IN ALBERTA, CANADA

Fusarium oxysporum, Pythium ultimum, and Rhizoctonia solani were isolated from the basal stems of diseased alstroemeria showing symptoms of dark brown stripes along leaf margins, leaf chlorosis, plant wilting, browning or rotting of basal stem, rhizome, and storage and fibrous roots. The pathogen isolated most frequently was Fusarium spp. (40.5 % of plants examined). Pythium spp. and R. solani were isolated less frequently (5.5 % and 6.8 % of plants examined, respectively). F. oxysporum caused the highest mortality in alstroemeria when rhizomes were grown in unsterilized soil-less mix medium. This is the first report in North America of a root-rot disease complex affecting alstroemeria.