The development of the novel fungicide - Dimethomorph

Dimethomorph, a cinamic acid derivative, is a novel fungicide active against members of the family Peronosporaceae and the genus Phytophthora. It has a long residual activity which embraces protectant, curative and antisporulant effects. Translaminar activity follows foliar application and dimethomorph is systemically translocated in the plant when applied to the roots/stem. The precise mode of action of dimethomorph has not been identified but studies to date imply a novel and very specific activity. Cross-resistance to phenylamides has not been observed indicating that the product will provide a valuable addition to the current range of Oomycete fungicides by providing disease control within a resistance strategy programme. Much of the early development of dimethomorph has been in temperate crops where excellent control has been demonstrated of Plasmopara viticola on vines and Phytophthora infestans on potatoes and tomatoes, particularly in mixture with contact fungicides. Recently investigation has extended to a wide range of crops to include Peronosporaceae in vegetables and Phytophthora sp. in crops such as pineapple, citrus, durian, pepper, rubber and cocoa. Such work has required application to both plant stems and to soil, as well as the more conventional foliar application. Results to date indicate an excellent performance with no crop phytotoxicity at dose rates required for effective disease control.