Incidence of rice blast in the collection of varieties and lines of rice at IPEAS in the 1966/67 agricultural year

Abstract

An attempt was made to estimate the degree of incidence of rice blast (Piricularia oryzae) in the collection of rice varieties and lines under natural field conditions at Instituto de Pesquisas e Experimentação Agropecuárias do Sul (IPEAS). The scale of 0 to 5 of the International Blast Nursery, based on the percentage of the foliar area infected, was used. It was verified that: 77 varieties and limes showed resistance (ratings 1 and 2); 452 varieties and limes showed moderate susceptibility (rating 3); 500 varieties and lines showed susceptible (ratings 4 and 5). The following was verified in relation to the degree of resistance to rice blast of the predominantely grown varieties in Rio Grande do Sul: Resistant varieties: Selection of Blue Rose (Blue Rose CI 166.970) Moderately susceptible varielies: Maravilha, Blue Rose, EEA 401, Bengue, Japonês Chumbo. Susceptible varieties: Caloro, Seleção 388, Guaíba, Stirpe, Rizzoto, Zenith, EEA 403, EEA 404, Japonês comum, Japonês meia pragana.