Abstract

The work on raspberry root rot began at SCRI with the widespread appearance of the disease in Europe in mid-1980s. Phytophthora fragariae var. rubi (Pfr) is the main causal organism but other species can cause similar symptoms, especially in very wet or waterlogged soils. Diagnostic tests, bait and DNA-based, can detect the pathogen at low levels in planting canes - the DNA test, in less than a day. Disease resistance, although not widespread in commercial cultivars, has been incorporated into breeding programmes but an early report of physiologic races of the pathogen has not been confirmed. Various fungicides control the disease but the best of these, Recoil (oxadixyl+mancozeb), was recently withdrawn in Britain. Application for an off-label approval (SOLA) has been made for fluazinam. Integrated control with reduced inputs of fungicide is possible with better drainage, ridging, plastic mulching and, especially, disease resistant cultivars.