American wildrice (Zizania palustris) has several known stem rot diseases: Bipolaris oryzae, B. sorokiniana, and Nakataea sigmoidea. The Bipolaris species also cause the foliar diseases fungal brown spot and spot blotch. Since these diseases have previously been the target of selection to improve varietal resistance, methods have been developed to inoculate leaves with conidia suspensions to develop resistant varieties. Selection for resistance to stem rots in wildrice has not been done. In this study, methods were developed for growing inoculum of N. sigmoidea and for delivering known quantities of propagules of all three species to the stems of wildrice varieties. In a replicated trial of 20 varieties and breeding populations, stems of 10 plants per plot were inoculated with each of the pathogens. Lesions developing from the inoculation sites were rated to quantify disease resistance for each disease. Effectiveness of the inoculation and assessment will be discussed, and resistance levels in each variety for each disease will be compared.