THE INCIDENCE OF CERTAIN SEED-BORNE DISEASES IN COMMERCIAL SEED SAMPLES II. ERGOT, CLAVICEPS PURPUREA (FR.) TUL., IN CEREALS

The incidence of ergot, Claviceps purpurea (Fr.) Tul., in commercial cereal seed samples submitted to the Official Seed Testing Station from 1918 to 1957 has been examined. Rye samples were more frequently contaminated than wheat or barley and no cereal ergots were recorded in oats. A relatively high proportion of ergot-contaminated rye samples occurred every 8-10 years. This appeared to be associated with high relative humidity and low maximum temperature during June. Similar trends were found for wheat and barley. No varietal differences in susceptibility to ergot contamination were found for rye or barley, but there was some evidence that spring wheat varieties were more frequently contaminated than winter ones.