Response of Eucalyptus Species to Field Infection by Puccinia psidii. J. C. Dianese, Associate Professor, Departamento de Biologia Vegetal, Universidade de Brasilia, 70910, Brasilia, DF, Brazil. T. S. De A. Moraes, Forest Researcher, Santa Bárbara Agriculture & Forestry Company, 30000 Belo Horizonte, MG, Brazil; and A. R. Silva, Forest Researcher, Rio Doce Forest Company, 30000 Belo Horizonte, MG, Brazil. Plant Dis. 68:314-316. Accepted for publication 4 October 1983. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-314.

Thirteen species of Eucalyptus with a total of 23 provenances (prs) were tested for resistance to Puccinia psidii in a field experiment with four replicates of 25 plants. Provenances were rated according to a scale based on the percentage of plants infected and the number of rust pustules. E. grandis pr South Africa was highly susceptible; E. grandis prs Coff’s Harbour, Kiogle Tablelands, and Garça, E. cloeziana prs Carbonita and Transvaal, and E. citriodora pr Florasa and E. saligna pr Cesanook were susceptible; E. urophylla pr Australia 9003, E. camaldulensis prs Gibb River and Petford, E. tereticornis pr S. Helenvale, E. pirocarpa pr Woolgoolga, E. paniculata pr Florasa, E. punctata pr Manduri, E. maculata pr Bom Despacho, and E. saligna pr Mt. Scanzi were moderately susceptible; E. pellita pr N. Australia 10966, E. microcorys pr Fabriciano, and E. urophylla pr Australia 10136 were resistant; and E. pellita prs Helenvale, Mt. Pandanus, and NE Coen were highly resistant. Rust did not affect height growth of two susceptible and four moderately susceptible provenances but did suppress growth of three other susceptible provenances. Except for E. grandis pr South Africa, all provenances were free of rust 1 yr after exposure to inoculum.

Keyword(s): rust resistance.