The development of synthetic fungicides; trends and prospects

Abstract

The presently available organic compounds which are being used for the combat of fungal plant diseases are reviewed.In most cases these molecules protect the plant by killing the attacking fungus before it has penetrated the plant; consequently we are dealing here with typical fungicides. Many attempts have been made to widen the scope of this principle by the development of compounds which are able to penetrate into the plant and which, consequently, may prevent the penetration of fungi from within or which kill fungi which have already penetrated. During recent years remarkable successes have been achieved with these so-called systemic fungicides.The newest approach is to look for compounds whict~ are neither fungi-nor phytotoxic but which disturb the biochemical relation between a fungus and its host plant in a specific way.These new approaches are illustrated with a few examples from recent work at the Institute for Organic Chemistry TNO at Utrecht. General considerationsThe present-day appreciation of human society at large for the use of chemical compounds in the fight against agricultural pests and diseases is very modest, to say it mildly. But even they who, either because of plain ignorance or in scarcely concealed maliciousness, fail to see any good in the contributions of chemistry towards saving our crops, have been rather generous as far as agricultural fungicides are concerned.