Coffee peel extract and thyme oil in the control of Cercospora coffeicola Berk &Cooke in coffee / Extrato de casca de cafà e Ãleo de tomilho no controle de Cercospora coffeicola Berk &Cooke em cafeeiro

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

The objectives of this work were: (i) to assess the effect of different doses of coffee berry husk extract (CHE) and thyme essential oil (TEO) on the germination and mycelial growth of Cercospora coffeicola; (ii) to assess the efficiency of CHE and TEO as possible resistance inducers in green house conditions; (iii) to biochemically characterize the effects of the resistance inducers CHE and TEO through the assay of peroxidase activity and lignification; (iv) to observe through scanning electron microscopy (SEM), the effects of these inducers on the spore germination and fungal development. It was observed that CHE had no fungitoxic effect on C. coffeicola conidia, promoting higher conidia germination in comparison with the control. TEO presented fungitoxic effect to the conidia in the concentrations of 500, 1000 and 2000ppm. The mycelial growth was inhibited in all CHE and TEO doses applied. In the green house trials, CHE (150g.L-1) and TEO (500ppm) reduced C. coffeicola incidence to 28.1% and 20%, respectively, in comparison with the control treatment. Plants that received only CHE had peaks of peroxidases activity in the seventh and eleventh days after treatment and, when inoculated the plants had similar behavior. Plants treated with TEO showed activity peaks in the second and third days after treatment, having another peak in the ninth day which was observed until the fourteenth day. In the inoculated plants it was observed a peak only in the first day after inoculation. There were not significant differences in the lignin concentrations fourteen days after treatment spraying. It was observed through SEM that CHE promoted better conidial germination and fungal development; on the other hand TEO reduced conidial germination and fungal development in all the times evaluated.

ASSUNTO(S)

induÃÃo de resistÃncia coffee plant extracts cercospora coffeicola extratos vegetais fitopatologia thyme oil indiced resistance cercospora coffeicola Ãleos essenciais cafeeiro

ACESSO AO ARTIGO

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