The peanut is a recent introduction into southern Ontario. In order to develop appropriate production practices, the effects of irrigation, inoculation and N fertilization on yield were investigated. Irrigation and inoculation each increased the yield by about 27%, and the effect of each of these factors was greater in the presence of the other. No significant yield difference (2992 kg/ha on average) was observed between the use of powdered peat or granular inoculants containing the same strains of rhizobia. However, a yield difference was observed between inoculants containing different strains of rhizobia. Nitrogen application at planting time did not increase the yield of uninoculated peanuts, but a split application, applied at planting and 60 days later, increased the yield by 28% over the uninoculated control. Increasing the N application at planting decreased the yield and 100-kernel weight of inoculated peanuts.