Resistance toSclerotinia trifoliorumin red clover collected from North Africa

Abstract

Introductions of red clover indigenous to the Atlas mountains of North Africa were shown to have a high degree of resistance toSclerotinia trifoliorumwhen a natural attack occurred in field trials at Cambridge. Differences between the two classes of clover varieties: (1) North African populations, and (2) the British varieties Essex broad red and S. 123, were highly significant for the proportion of row affected, the number of affected areas and the average length of affected area. The North African material is expected to be a useful source of resistance toSclerotinia trifoliorum, in breeding programmes.We are indebted to Mr H. H. Rogers for his guidance and for collecting the red clover plants during the 1962 North African expedition which was supported by the Agricultural Research Council. We also acknowledge valuable criticism of the manuscript and provision of a computer programme by Mr J. L. Fyfe and help with field records by Mr M. Pope and Mrs H. E. Pape.