: In the trial with different doses of common bunt teliospores used for inoculation of wheat the number of bunted ears increased with the increasing dose of inoculum. This increase was small (statistically insignificant) in the resistant cv. Bill and high (statistically significant) in the susceptible cv. Samanta. The effect of inoculation on the vigour of inoculated plants was estimated according to the number of tillers per plot in summer in cultivars inoculated with different inoculum doses sown at the same sowing rate in autumn. The number of tillers was decreasing with the increasing inoculum dose. This was less pronounced in the resistant cv. Bill than in the susceptible cultivar Samanta. Competition between Tilletia tritici and Tilletia laevis during infection was studied by inoculation with a 1:1 mixture of teliospores of these species and scoring bunted ears. Ears bunted with T. laevis prevailed in almost all trials. The germination test of teliospores showed a higher speed of germination of Tilletia laevis teliospores. The number of teliospores per seed after inoculation was counted. No significant difference in the number of teliospores per seed after inoculation with T. tritici or T. laevis was ascertained.