Abstract
A survey of virus-like symptoms in yam foliage was carried out in seven islands of the Commonwealth Caribbean during late 1974. Five species of food yams (Dioscorea alata, D. cayenesis, D. rotundata, D. trifida and D. esculenta) were examined and an average disease incidence of 48 per cent was recorded. Electron microscopic examination of leaf dip preparations indicated the presence of one type of virus particle, a long, flexuous rod 770 nm in length. This virus-like particle was detected in 50 per cent of the samples examined from all five species showing all the different symptom types.
