Effects of volatile products of Allium species and their extracts on germination of sclerotia of Sclerotiutn cepivorum Berk.

It was shown that sclerotia of Sclerotium cepivorum, normally subject to the mycostatic influence of unsterile soil, germinated in response to a volatile principle evolved from growing onion and leek seedlings. Air, which was bubbled through diluted onion and garlic juices, contained vapours which stimulated sclerotia! germination. The vapours evolved at room temperature by garlic juice were collected as a condensate which also induced germination. Stimulatory activity was found in both distillates and distillands of garlic as well as in air bubbled through such a distillate.