You get dual action with Orvego fungicide: ametoctradin is a strong inhibitor of mitochondrial respiration in Complex III (cytochrome bc1) of oomycetes fungi. The active ingredient is classified by the US EPA as a Group 45 fungicide. Dimethomorph belongs to the group of cell-wall synthesis inhibitors classified by the US EPA as target site of action Group 40 fungicides. Orvego acts as a penetrant with translaminar and locally systemic activity following a foliar application. When used as a soil drench, it protects plant roots and crown as a translaminar, locally systemic fungicide.