This 16-page report summarises the key outcomes from laboratory and field trials conduted during 2002 – 2004 under project VG01096, “Stop the rot – managing onion white rot in spring onions”. Onion white rot, caused by Sclerotinia cepivorum, can result in severe crop losses (in spite of the widespread use of sprays of the fungicide procymidone, which has now been withdrawn by the APVMA) because intensive cropping has led to a build-up of inoculum (sclerotia) in the soil. The report covers improved spray application trials, evaluation of fungicides and biocontrol treatments and evaluation of DADS and other treatments for inoculum reduction in soil.