13 December 1996

Virus warning

on seed spuds

ABOUT 40% of home-saved seed potato samples tested so far by ADAS this season contain more than the 5% maximum virus limit recommended for planting.

Thats despite low aphid levels early in the season. A sudden late flush of the pests seems the most likely source.

Although the recommended limit can be stretched for non-susceptible first earlies up to 10% without economic yield loss, growers with other types should play safe and look to certified sources, says Huntingdon-based agronomist Paul Dover.

Test results are usually available within six weeks of the sample arriving at the Wolverhampton laboratory. The test is carried out on growing shoots, and costs £130 a sample. Growers should pick 120 tubers at random from each potential seed lot.

Further details from Andy Phillips, ADAS Wolverhampton (01902-754190).n