Actavia 0 Hiemstra, J.A. 2002 2002-12-31 656-658 Verticillium wilt is of increasing significance in European agriculture, especially in tree hosts such as olive and stone fruits, and in shade tree nurseries. In the period 1997-1998 eight European research groups participated in an EU-funded Concerted Action on this disease. Main results were the publication of "A Compendium on Verticillium wilts in tree species" (HIEMSTRA & HARRIS 1998) and an RTD-proposal submitted for financing to the 5th EU Framework Programme. This proposal was approved by the European Commission and the research started in March 2000. Ten research groups participate in a project that aims to provide essential elements for an efficient and environmentally sound management of Verticillium wilt in trees. The research concentrates on tree key areas: (1) pathogen variability, (2) host resistance, and (3) detection and risk assessment. In addition the project aims at harmonising methods, exchange of experience and continuation of the successful co-operation developed during the previous Concerted Action. The specific achievements of the project include information on genetic variation within the pathogen and on distribution and virulence of its subspecific groups; standardised methods to select for host resistance; resistant selections of olive and maple; molecular methods to detect the pathogen in soil and plants; and improved risk assessment procedures. Details on aims, methods and participating groups will be presented. 11 38