AbstractFour-plant clones of nine varieties were grown in polyethylene tunnels for up to three years, with the irrigation controlled so as to provoke infection by S. macularis. Cambridge Favourite was the most resistant. Five-year assessments in the field agreed well with these results. Indications of resistance obtained in young seedlings failed to agree with either. Resistance to Ph. cactorum was assessed by inoculating petiole bases and detached leaves and recording the timing of response and the rate of spread of necrosis. The rate-of-spread method provided clearer differentiation among relatively resistant varieties. Templar was the most resistant. In a separate investigation, the rate of spread in the diploid Fragaria vesca was only slightly less than in its tetraploid and decaploid derivatives 69JV28 and 74V119.5, and much less than that in three octoploid varieties. The inoculation of young seedlings gave similar results and showed that the octoploids transmitted their susceptibility to their progenies.