The Fusarium head blight. Wheat spike is one of the most important diseases of wheat in the world. One of the main problems of crop production in our country is the difference between farmers' actual yield and yieldable yield (yield gap). Understanding performance constraints can help researchers reduce their performance gap. One of the main living restrictions on wheat production in the fields located on the northern strip of the country overlooking the Caspian Sea, as well as Moghan area, is Fusarium spp. Wheat spp. Or FHB. This study was conducted to evaluate the functional vacuum caused by spit blight of Fusarium spike in different bread wheat cultivars (including 21 cultivars) including rainbow and blue currents in northern Iran, as well as several tolerant and highly sensitive standard cultivars in three replications Became An environment with disease stress and a disease-free environment, which was carried out in a stressed environment with wheat spike with spore suspension of fungi and in a non-stressed environment, Falcon has been used to control the disease. Subsequently, Functional including 1000-grain weight and yield of grain was measured. Analysis of performance data using compound analysis showed that among the cultivars of rainfed cultivars Qaboos and aftab, among the cultivars of Morvarid cultivar, the best cultivars were in response to Fusarium spike blight. In this regard, the cultivars Qaboos and Aftab have been identified as having the least suitable functional vacuum for cultivation in the areas with epidemic of Fusarium officinalis. From the results of this research, it is possible to carry out corrective research in order to identify and correct the cultivars with the least yield reduction in the equivalence of Fusarium haed blight.