New physiologic race of Uromyces phaseoli typica in southern Brazil

Abstract

A survey of physiologic races of bean rust (Uromyces phaseoli typica Arth.) was conducted on samples collected in Rio Grande do Sul and Santa Catarina in the agricultural years 1967/68 and 1968/69. Some isolates showed different reactions on the varieties of the differential series from those observed for the races previously described. The occurrence of a new race, that was designed B₁₆, was established in this way. The annual survey of physiologic races should he continued so as to make possible the evaluation of the frequency of this race as well as others. The research of resistant sources to this race should be initiated.