Partial resistance of oat genotypes to crow rust

The aim of this study was to determine the different levels of resistance t o crown rust of oat genotypes, and to evaluate its effects on yield compone nts. The experiments were carried out at the agronomy experimental station of the Universidade Federal do Rio Grande do Sul, in Rio Grande do Sul, Bra zil, in 1995 and 1996. Ten genotypes with differentiated reactions to the d isease were evaluated. Crown rust caused damage to grain yield, in differen t crop densities, and grain weight was the most affected yield component. H owever, some genotypes like UFRGS 910906 were not affected even at intermed iate levels of the disease, showing thereby the possibility to combine part ial resistance and yield potential in the same genotype.