Fontes de cobre no controle da ferrugem do cafeeiro

Abstract

This study aimed at to evaluate of sources and doses of copper chelates of different concentrations on the control of coffee rust, two experiments were conducted, one in vitro in the laboratory, and another in vivo, in seedlings conducted in a greenhouse. The treatments for both experiments were the same, which consisted of 5 g. L -1 copper oxychloride, copper oxide 2.5 g.L -1 , copper hydroxide 5.0 g.L -1 , copper nitrate 0.35 g.L -1 , chelated copper with glucone 3.75 g.L -1 , copper EDTA (1, 2 g.L -1 ; 2.5 g.L -1 ; 5.0 g.L -1 ; 12 g.L -1 ) and copper sulfate 10 g.L -1 in 4 replicates. The experimental design was in randomized blocks. In the experiment "in vitro" evaluated the effect of the treatments on the germination of uredinióspores of Hemileia vastatrix. In the second, it evaluated the efficiency of the different sources and doses of copper in the control of coffee rust. Evaluations of the disease were performed weekly, severity was performed with a diagrammatic scale. The variables were statistically analyzed, applying the Tukey test at 5% of significance. In Experiment 1, all treatments were efficient in inhibiting the germination of urediniopores, with the exception of Cu-EDTA, which at all doses did not differ from the control. In experiment 2, a decrease incidence was observed with the application of copper nitrate and chelated copper with glucone, with control of 65.2% and 62.6%, respectively, in relation to the contro. For the severity the control was 81.5% and 80.4% when applied copper hydroxide and copper nitrate. The weight of the dry aerial part of the treatments differed from the control, with the exception of Cu-EDTA in its different doses. There was no statistical difference between treatments for photosynthesis and chlorophyll content.