3 May 1996

Dipstick seed

test for virus

Seed quality, crop nutrition and variety chocie were just some of the topics discussed at last weeks Potato 96 event at Stafford and a PMB technical conference the day before. Andrew Blake reports

NEW dipstick tests to assess potato seed quality should give growers more confidence in the stocks they plant, according to the PMBs research scientist Dr Robert Clayton.

The diagnostic method, based on an ELISA technique developed at the Scottish Crop Research Institute and the Central Science Laboratory, spots viruses early in crops intended for home-saved seed and assesses blackleg levels in stored tubers.

Trials last season confirmed its potential in detecting PVY and PLRV before burning off. But field sampling needs tightening to ensure useful results, Dr Clayton suggested. A programme of staff training to help growers adopt the correct procedure to obtain fully representative samples is planned, he said.

Compared with earlier bulking methods, the new blackleg test should be able to pinpoint parts of stores with different levels of infection. This could allow growers to discard unsuitable stocks or modify their husbandry as required, he explained.

The tests are still at the pre-commercial stage, but they cost about £100 for each 100 samples required.

&#8226 New "dipstick" test.

&#8226 Checks for viruses and blackleg in seed.

&#8226 Requires careful sampling.

&#8226 About £100 for 100 samples.

New technology means seed potatoes can now be tested for virus and blackleg using this simple dipstick kit, explains Dr Robert Clayton.