PEA downy mildew is the most common disease of both vining and combining peas in the UK, a demonstration day was told.

The current conventional control options are limited to seed treatment, rotational management and varietal tolerance.

But Dr Kerry Maguire explained that, with the John Innes Centre, the PGRO began a project in February to investigate the race structure of downy mildew across the UK.

She appealed to all growers to help the PGRO collect downy mildew infected pea plant samples.

“We would like to request that all growers send diseased plants to our plant clinic,” she said.

“We are interested in receiving samples from all parts of the UK. Samples should be placed in a polythene bag and sent to PGRO.”

Downy mildew is soil-borne and causes significant plant loss early in the season.

Primary infection occurs at emergence, and plants are pale and stunted, with a grey-mauve velvety growth on the underside of leaves.

This spreads to the rest of the crop to cause secondary infection.

There are several types of pea downy mildew, and fields with a history of infection may contain a mixture.

Some varietal tolerance exists in commercial varieties, but many are very susceptible and often suffer losses when sown early in the season.

Dr Maguire said the project would help to provide growers with information about the geographic incidence of the disease and varietal tolerance to different types.

“Information from the project will be used by the breeding industry to develop improved resistance in pea varieties,”

she said.

Samples should be sent to Dr Kerry Maguire, PGRO, The Research Station, Great North Road, Thornhaugh, Peterborough, PE8 6HJ.

Pre-paid envelopes are available on 01780 782585 or see