Treating Giza, 159 rice cultivar (highly susceptible to blast disease) with Oryzemate granule fungicide at different doses resulted in different degrees of panicle blast infection. Crain yield per plot, per plant, per panicle and protein content were correlated with the severity of panicles infection. A significant negative correlation coefficient was found between severity of panicles infection and yield loss at the two locations (Diarb Negm and Hehya) during the two seasons (1989 and 1990). An increase of ?% panicle blast severity corresponds to a 0.54% and 0.91% loss of grain yield during 1989 and 1990 seasons at the first location, while at the second location it corresponds to a 0.82% and 0.78% loss of grain yield during 1989 and 1990 seasons.