NEMATODES AND PLANT HEALTH - LEGISLATION AND SAMPLING STRATEGIES IN DECISION-MAKING FOR NEMATODE MANAGEMENT

UK plant health measures are based principally on the Plant Health (Gr eat Britain) Order 1993 and the similar Order covering forestry pests, both implementing EU Directive 77/93/EEC, as amended. Nematode specie s of quarantine status are Aphelenchoides besseyi, Bursaphelenchus xyl ophilus, Ditylenchus destructor, D. dipsaci, Globodera pallida, G. ros tochiensis, Longidorus diadecturus, Nacobbus aberrans, Rhadopholus sim ilis, Xiphinema americanum sensu late (non-European populations), and X. californicum. Soils are tested for freedom from Globodera spp. and virus vector nematodes under certain certification schemes and where n ecessary, for export crops. EU Marketing schemes require visual freedo m from quality-affecting nematodes. Soil samples normally comprise 500 g of soil from 100 cores per 4 ha (or less).