Com o objetivo de detectar níveis de resistência horizontal, foram inoculados com uredosporos de cada uma das raças I, II, III, VIII, XV e XXIV de Hemileia vastatrix mudas, folhas destacadas e discos foliares de progênies de cafeeiros Catimor e Cavimor, em geração F3 e F5, e de progênies, em geração F1 e F2, de cruzamentos entre Cavimor e o Cultivar Catuaí. Dentre 12 progênies de Catimor e Cavimor, as menores porcentagens de germinação de uredosporos foram observadas nas progênies UFV 4181 e UFV 4269, nas avaliações realizadas oito horas depois da inoculação. Considerando (1) o grau de reação, (2) a severidade de doença, (3 ) a razão de esporulação e (4) a intensidade de esporulação como critérios individuais de avaliação de resistência, as progênies UFV 4269, UFV 4280, H8-1 e H3-9 sempre apresentaram os maiores níveis de resistência horizontal dentre todas estudadas. Nas avaliações para resistência, os resultados mais consistentes foram obtidos nos ensaios com mudas e folhas destacadas. As raças II e III de Hemilieia vastatrix, dentre as estudadas, destacaram-se como as mais agressivas.
A study was carried out to detect different levels of horizontal resistance on coffee inoculated with Hemileia vastatrix uredospores. Young coffee plants, detached leaves and leaf disks of different coffee progenies derived from Catimor, Cavimor, and crosses between Cavimor and Catuaí cultivars were inoculated with uredospores from each one of the races I, II, III, VIII, VX and XXIV of Hemileia vastatrix. The lowest percentage of germinated uredospores was observed, eight hours after inoculation, in Catimor progenies UFV 4181 and UFV 4269 when they were compared to those of ten other Catimor and Cavimor progenies. Results of assessing resistance by reaction type disease severity, sporulation ratio and sporulation intensities on coffee rust lesion were equally adequate, and consistent when the inoculation was performed on detached leaves or on leaves of young plants, and not consistent on leaf disks. Each one of these criteria was good in establishing that progenies UFV 4269, UFV 4280, H8-1 and H3-9 always presented the highest levels of horizontal resistance. Races II and III of Hemileia vastatrix were the most agressive among all tested.
