Disease Note.

First Report of Colletotrichum gloeosporioides on Lupine in Canada. T. C. Paulitz, Macdonald Campus of McGill University, Ste Anne de Bellevue, Quebec, H9X 3V9. G. Atlin and A. B Gray, Nova Scotia Agricultural College, Truro, Nova Scotia B2N 5E3. Plant Dis. 79:319. Accepted for publication 10 February 1995. Copyright 1995 The American Phytopathological Society. DOI: 10.1094/PD-79-0319D.

A severe rot and collapse of the upper inflorescence stems was observed on white lupine (Lupinus albus L.) grown in Truro and Nappan, Nova Scotia, in summer 1993. Sunken lesions completely perforated green stems; the stems bent at the sites of the lesions as a result of the weight of the pods. Pink-colored spore masses arising from hyaline, glabrous acervuli were observed around the lesions and contained hyaline, cylindrical conidia 3-5 x12-17 μm. Similar spore masses were observed on rotting pods from a field in Joliette, Quebec, in 1992. Single-spore cultures were made from acervular conidia. The fungus, identified as Colletotrichum gloeosporioides (Penz.) Penz. & Sacc, in Penz., (teleomorph = Glomerella cingulata) was grown in potato-dextrose broth for 7 days and spores were collected by centrifugation Three-week-old white lupine plants grown in a growth chamber at 22 C were sprayed to runoff with a suspension of 101 conidia per milliliter. Inoculated plants were covered with plastic bags and incubated for 48 h in the growth chamber. On other plants, puncture wounds were made with a 25-gauge hypodermic needle and a drop of spore suspension was placed on the stems. Tenmicroliter drops of spore suspension were placed on wounded and non-wounded green pods, which were incubated in petri dishes with moist paper filters. After 10 days, typical symptoms were observed on spray-inoculated and stem-inoculated plants. Rot developed at the point of inoculation in wounded pods only. The fungus was reisolated from acervuli in the lesions. This pathogen was reported on blue lupines in the southern US. in the 1940s and has been recently reported on while lupines in Minnesota and France. The disease has become a major limiting factor for lupine production in (he Maritime region of Canada, and may prevent its establishment as an important agronomic crop.