European wheat striate mosaic disease in 1970

A greater prevalence of European wheat striate mosaic was reported in English winter wheat crops in 1970 than in any previous year and loss of yield in one crop was probably as much as 10 per cent.

At Rothamsted, infected plants were first found at the beginning of May and symptoms appeared in others until the middle of June. Most infections probably occurred before spring cereals emerged but a few plants became infected in spring‐sown crops. Most infected plants produced no grain. The mild autumn of 1969 and a previous crop of spring wheat may have been partly responsible for the unusually prevalent infection at Rothamsted.