Two Septoria Monitoring Nursery sets were tested for resistance in the field during three consecutive years. Different concentrations of oat grains covered with mycelia of Septoria tritici were applied as inoculum. The position of the disease on the plants and the severity of the Septoria leaf blotch infection were recorded at two growth stages. A comparison between leaf pulverisation and grain application as a source of conidia was made in the last year. The percentages of necrotic lesions and pycnidial coverage were recorded on the upper three leaves of the plants at the same growth stages as for previous years. With grain inoculation, the infection reached the 7th leaf of the plants with the maximum concentration applied at tillering stage. The best concentration to obtain the highest discrimination among resistances is 120 g/m². In the comparison of inoculation techniques, the results showed a higher necrosis and pycnidial coverage following leaf pulverisation than with the grain application treatment.