The report presents the results of the use of the method of rapid strain trial of spring cereals under the conditions of the northwest of Russia. The method of rapid ecological estimation of the range of crop yield responses of novel candidate cultivars of spring cereals (rapid ecological crop trial, RECT) provides an example of the system approach to the analysis of data of ecological trails. The algorithm of data treatment provides for the complex diagnostics of crop yield. In a programmed physico-agronomic experiment (carried out in 1998-2000), 3 wheat and 3 barley cultivars were characterized by rates of lesioning by different diseases including mycoses caused by Erysiphe graminis, Puccinia recondite, Septoria nodorum and Pyrenophora teres. Preliminary statistical data processing has shown that crop yield decreased depending on plant lesioning rate (correlation coefficient r=-0.74). Plants with adventitious shoots were lesioned more (r=0.69). Clearly, the new cultivars were more pathogen-endurable compared with standard cultivars. The plants were more often infected under the conditions when the following root rots developed: Fusarium, Helmintosporium, Alternaria, etc. (r=0.67). Fungus-endurable cultivars will be more preferable than fungus-resistant ones because of a better balance between the plant and the environment. The methodology of accelerated strain trail at the stage of competitive evaluations will allow to better characterize the appropriate zoning of the strains and their ranges of responses related to crop yield and resistance to fungal pathogens.