Abstract
Ethanol extracts of filter paper and cotton contain a germination stimulant which counteracts the self-inhibitor in stem rust uredospores. The major active component was purified with ion exchange resins and alumina and was partially characterized. It is nonvolatile, nonionic, has a UV absorption peak at 285 mu and an infra-red spectrum indicating a long chain [pound sterling], [beta] unsaturated carbonyl compound. Concentrations of a few ppm stimulated both germination and 02 uptake.