INDEPENDENT VARIETY TRIALS (IVT) Industry considers it very desirable to compile a comprehensive independent data set of varietal ratings for diseases considered to be of most importance for GB potato production.  To this end, the Potato Council fund a set of tests for some diseases not covered by the official National List programme.  This testing is fully integrated with the official testing to maximise the efficiency of the current variety test programmes. The diseases assessed in Independent Variety Trials are foliar late blight (Phytophthora infestans) in the field, black dot (Colletotrichum coccodes), black scurf (Rhizoctonia solani), silver scurf (Helminthosporium solani) and skin spot (Polyscytalum pustulans). Agents/breeders of varieties entering 2nd year of UK National List are invited to enter their varieties for IVT testing .  In addition, agents/breeders of varieties on the Common Catalogue of European Union intended for production in GB are also invited to enter their varieties which are subject to testing according to UK National List procedures for tuber late blight, blackleg (Pectobacterium atrosepticum), common scab, powdery scab, dry rot (Fusarium coeruleum and F. sulphureum), PCN (Ro1, Pa2/3 and 1), splitting and bruising.  The results of all tests are published on Potato Variety database of the Potato Council (http://www.varieties.potato.org.uk). The IVT test programme is organised and conducted by a consortium led by SASA and comprising SAC, BioSS and SCRI.