Este trabalho visou estudar os mecanismos envolvidos na defesa de mudas de café tratadas com extratos de plantas contra Cercospora coffeicola. Para determinação dos mecanismos envolvidos, selecionaram-se os extratos que proporcionaram maior proteção de cafeeiro contra C. coffeicola em experimento previamente realizado, ou seja, extratos aquosos de folhas de café com ferrugem, de ramos de lobeira com vassoura de bruxa e de cascas de café. Observou-se que os extratos proporcionaram aumentos na atividade de peroxidases aos vinte dias após a pulverização, a exceção do extrato de vassoura de lobeira, o qual apresentou maior atividade aos 15 dias, semelhante ao indutor de resistência padrão acibenzolar S- metil (ASM). Quanto ao teor de lignina, observou-se maior acúmulo para o extrato de folhas de café infectadas com ferrugem.
This work was aimed at studying mechanisms involved in the defense of coffee seedlings treated with plant extracts against C. coffeicola. For determination of the involved mechanisms, the extracts that induced higher protection of coffee seedlings against C. coffeicola were selected, i.e., the extracts from husks of coffee berries, coffee leaves with rust and branches of ‘lobeira’ (Solanum lycocarpum). It was observed that these extracts provided increases in peroxidase activity twenty days after spraying, except the extract from branches of ‘lobeira’, which presented higher activity at 15 days, likely the resistance inducer acibenzolar S-methyl (ASM). Regarding the lignin content, higher accumulation was observed for the extract from coffee leaves with rust.
