Abstract Wageningen UR Greenhouse Horticulture, together with Syngenta Seeds tested various combinations of agents for their effects to increase plant defense against infection of downy mildew in the consumer phase. All means were dosed 2-3 times during the growers phase. There are three new products, which were found to strengthen Impatiens plants against infection by downy mildew. It is still unclear how these products can be combined with other agents that also control pathogenic soil fungi so that failure occurs less rapidly under field conditions at high disease pressure. In 2011, this research will be continued at two field locations
