Regarding the periodic fluctuations of water supply in some areas of sugar beet cultivation in Iran, farmers, in terms of the growth stage of sugar beet refrain from regular irrigation due to limited water resources. Due to the effect of soil moisture on host physiology, pathogen and their interactions, it is important to evaluate the extent of the loss development caused by Rhizoctonia before and after the drought periods. To investigation this issue 30 commercial sugar beet cultivars, most cultivated by sugar beet growers, were evaluated to compare the resistance and their probability of predisposition against R. solani under field conditions. In order to confirm the results of the field experiment, the inoculation of these cultivars was carried out in the pot with the Rhizoctonia inoculum. The results of this study showed that the percentage of root rots in post-stress periods was higher in stressed plots compared to control plots. The results analysis of area under disease progresse curve (AUDPC) showed a significant difference between AUDPC in treatment and stress free plots. The results of evaluation of of the 30 commercial cultivars in greenhouse conditions against Rhizoctonia showed that 14 cultivars Shokoufa, Palma, BTS335, Iris, Toukan, Linda, BTS233, Perfecta, Flores, DS4057, Delta, Ghazira, Baloo and Murialle have a significant resistance and the results of the experiment were consistent with farm results. According to yield and resistance of cultivars in field conditions, Palma, Iris and Toucan cultivars are recommended as suitable cultivars for stress conditions in the presence of rhizoctonia patient.