Induction of Systemic Resistance in Cauliflower to Downy Mildew by Exogenous Application of Plant Activator

Exogenous application of CGA 245704 (BTH) induced systemic resistance to cauliflower leaves to Peronospora parasitica by foliar application prior to pathogen attack Time course resistance induction studies showed that maximum induction was 3 days after treatment with either low concentration (20 mg/L⁻¹) or high concentration (50 mg/L⁻¹). Higher concentration caused phytotoxicity to the leaves. The induced resistance persisted upto 28 days after treatment. The effect of Bion was transmitted to leaves at nodes both above and below treated leaves. Chemical induction of systemic reistance offers a novel approach for managing downy mildews.