Resistência de progênies de café Catimor à ferrugem

to study the performance of catimor genotypes, field tests were done to evaluate their productive capacity and rust incidence, while horizontal resistance of seedlings to race ii of hemileia vastatrix was tested in the greenhouse. the reaction to the pathogen was evaluated on a scale of 0 to 9 where: 0 to 3 = resistant plants and 4 to 9 = susceptible plants. the components of quantitative resistance evaluated were: infection frequency, sporulation, lesioned foliar area, incubation period and latent period. progenies ufv 5550, ufv6861, ufv 6870, ufv6831 and ufv 6834 showed similar productivity to the catuaí cultivar (p < 0.05). progenies ufv 5530, ufv 5451, ufv 5550, ufv 6903 and ufv 5464 produced no diseased plants. the descendents of the progenies in this study varied greatly for rust reaction, with continuing variation from full resistance to high susceptibility, with the majority at intermediary levels. this indicates the presence of quantitative resistance in these genotypes. compared to the catuaí cultivar, it can be concluded that the studied genotypes had quantitative resistance, with the average number of lesions and lesioned foliar area 13 to 21 times less, respectively, on ufv 6866. the sporulation of ufv 6870 reached 0.1, a very low score if compared to catuaí's score of 3.6. the incubation period of the studied genotypes varied from 18 to 36 days and the latent period from 20 to 46 days. compared to the catuaí vermelho iac 15 cultivar, it can be concluded that the great majority of catimor genotypes studied had quantitative resistance.