Abstract
BROWN SPOT In order to clarify the general tendencv of the varietal resistance of rice to the brown spot(Cochliobolus"miyabeanus(ITO et KUPIB.)DRECH sL.), 283 varieties native to the diffrent latitudinal regions in Asia were employed for the inoculatiorn tests. The seedling were grown under the meage nutritional condition so as to make them susceptible to the diseage.When the seedling attaind the 3-4 leaf-stage, they were inoculated simultaneously with conidial suspension, then all the varieties were classified into six grades of infection, i.e., highly resistant, resistant, moderately resistant, moderately susceptible, and highly susceptible. So far as the precent experiment was concerned, in general, the variety-groups belonging to the so-called'Japonica'type, i.e.,
