Indutores de resistência contra a vassoura-de-bruxa no cacaueiro: mecanismos de ação e avaliação em campo

Abstract

The present work aimed at evaluating alternative methods for witch´s broom control, based on the broad spectrum resistance induction, compatible with other strategies already employed in the disease integrated management in the field. The biochemical mechanisms of defense induced in cacao were also studied for the most effective resistance elicitors. To achieve the established objectives, the following experiments were performed: 1. Characterize the biochemical mechanisms involved in cacao seedling defense responses when sprayed with Agro-Mos®, compared to those sprayed with ASM (Acibenzolar-S-Methyl); 2. Evaluate Agro-Mos® and Fulland® in the protection of cacao plants against witch´s broom in a field at Espírito Santo State; 3. Evaluate Agro-Mos® in the protection of cacao plants against witch´s broom in afield at South Bahia State. In cacao seedlings treated with Agro-Mos® an increase in the synthesis of guaiacol peroxidase, polyphenoloxidases, chitinases and ß-1, 3-glucanases was observed when compared to water control plants. In Espírito Santo State, Agro-Mos® reduced the witch´s broom incidence in adult cacao trees, when used at the 5 mL L-1 rate (68.5% disease reduction compared to the control). Fulland® and ASM did not present consistent results in disease control in the field. In Bahia State´s experiments, Agro-Mos® reduced witch´s broom incidence in cacao plants at the 10 mL L-1 rate with 54.1% disease control compared to the control. None of the tested products interfered on cacao bean yield.