RESISTANCE OF PHYTOPHTHORA-PORRI TO METALAXYL

Metalaxyl resistance has been identified in the Phytophthora porri pop ulation in the UK. In held experiments the presence of such resistant strains reduced the level of control of leek white tip given by applic ations of phenylamide-containing fungicides. The level of control achi eved by fungicides with alternative modes of action to the phenylamide s was not affected.