Plant extracts and commercial products for the management of coffee rust and mechanisms of coffee defense against Cercospora leaf spot. / Extratos vegetais e produtos comerciais no manejo da ferrugem e nos mecanismos de defesa do cafeeiro à cercosporiose

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

The aim of this study was to evaluate the effect of plant extracts and commercial products against rust in a conventional farming system. Furthermore, to assess the defense mechanisms of coffee seedlings against Cercospora leaf spot. The rust experiment was conducted in a coffee field (Cultivar Rubi) with 10 year old at the campus of Federal University of Lavras. The following inductors were tested: extract of coffee husks (CFC), extract of leaves of coffee infected with Hemileia vastatrix (EFID), the mixture of these with each other and with the inducer of resistance ASM (Acibenzolar-S-methyl), copper phosfite (5 and 10 mL.L-1) and Agro-Mos (doses 2, 5 and 10mL. L-1). A randomized blocks design with four replications was used. Coffee trees were sprayed monthly in the period from February until May 2007. The best results among the extracts were provided by a mixture of EFID with ASM and EFID alone, which reduced the area under the disease progress curve (AUDPC) in respectively, 52% and 26%, when compared to the control. Among commercial inducers, copper phosphite reduced the AUDPC up to 81% compared to the control. Agro-Mos presented intermediate performance compared to other treatments. In biochemical tests with coffee leaves from the field, there was no significant difference among treatments concerning lignin and total phenolics contents. Another experiment was conducted with coffee seedlings to assess defense mechanisms against Cercospora coffeicola. It was observed that copper phosphite and EFID + ASM provided increases in the activity of peroxidases at 21 and 11 days after spraying, respectively. Plants treated with these products showed increases in the activities of chitinases and β-1, 3 - glucanases. A higher content of total phenolics was also observed in plants treated with EFID + ASM and copper phosphite, compared to the control.

ASSUNTO(S)

coffea arabica coffee protection induction of resistance fitopatologia cescospora coffeicola alternative products coffea arabica proteÃÃo do cafeeiro produto alternativo hemileia vastatrix induÃÃo de resistÃncia cercospora coffeicola hemileia vastatrix

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