Chances of overturning the European Commission's ban on the importation of UK seed potatoes remain 50:50 despite the buyers on the continent keen to support the Scottish market.

That was the stark warning from Patrick Hughes, head of the potato export development at AHDB, speaking at last week's SACAPP virtual conference, who said that while the issue is being discussed at present, it is unlikely that a decision will be made until later in the month.

He also admitted that while there had been a flurry of orders from European growers looking for Scottish seed before the end of December, 2020, time is running out to enable more high health status Scottish seed to be shipped across to the continent when their growing season is fast approaching.

“Europe has effectively banned the importation of UK seed potatoes and while negotiations are underway to get recognition for high health status Scottish seed, Defra could only lodge an application to begin discussions on the issue after the transition period ended on January 1.”

While ware potatoes have been granted third country equivalence to allow the continuation of exports to the EU, seed potatoes are considered to be of higher risk category, as they could be used for further multiplication on mainland Europe and Northern Ireland. The UK’s refusal to accept dynamic alignment with Europe has as result, produced the effective ban.

However, while no seed can be exported to Europe at present, potato seed can be imported from the continent for the first six months of 2021.

The other issue affecting Scottish growers is the fact that seed exported to Europe is of different varieties to those preferred in the UK and therefore could be a challenge to sell.

While the fall out between the UK and Europe continues, producers from the continent may be cutting off their nose to spite their face with the news that the health of Scotland's seed crop is far superior to that of both the Netherlands and France.

Speaking on the second day of the SACAPP virtual conference, Christophe Lacomme, a senior virologist at SASA, told attendees that while the acreage of virus found in Scottish seed potatoes was slightly up on 2019 figures, the amount downgraded was significantly less than the main seed producing countries in Europe.

"Some 83% of the crop in Scotland showed no signs of virus last year," said Mr Lacomme.

"Of all the seed potato crop area inspected for symptoms of virus infection in Scotland, just 14% was downgraded, which compares to 35% in the Netherlands and even more in France.

"Most of the virus found in downgraded crops in Scotland was Potato Virus Y (PVYn) (67.3%) with Potato Leaf Roll Virus (PLRV) coming in next (18.6)."

He added that some varieties attracted more virus than others with Maris Piper in particular more susceptible to PLRV and PVYn at 49% and 23%, respectively, in 2020.

Looking at the 10-year average within varieties did nevertheless show differing levels of susceptibility, with Daisy most affected by PLRV at 8.5 followed by Maris Piper at 3.1, Cara at 2.5 and Maris Peer at 1.7.

Similarly, the 10-year average incidence of PVYn in Maris Piper was 1.8% which compares to the highest of 5.3 found in Atlantic and 2.7 in Maris Peer, King Edward and VR808 seed.

Mr Lacomme put the 2021 prediction for PLRV at 3.5% which compares to the 2020 observation of 4.5% and expected level of 3.1%.

Last year, the actual crop area of seed potatoes with at least one plant showing symptoms of PVY was 17.5% compared to the 2020 prediction of 19.2%, with the forecast for 2021 at 13.3%.

Across The Pond, Mathuresh Singh of Agricultural Certification Services Canada said the incidence of PVY has been declining in New Brunswick, over the past decade as a result of improved management and the use of clean seed.

He told delegates that the incidence of the virus had gone from infecting 11.8% of the crop in 2009 down to 0.40% last year with 70% of the crop tested.

Such was the challenge presented by new strains of the virus that there was only 15% clean seed available in 2009.

However, a change in government policy which put a cap on the amount of infected seed that could be planted coupled with testing for the virus post harvest, slowly reduced the amount of infection in crops. Add to that earlier and more regular applications of insecticides containing an oil mix to kill off the aphids, has not only reduced virus levels but also significantly improved yields.

Seed spraying programmes now commence on average at the end of May – two weeks earlier than they did in 2009 – with a minimum of one oil spray per week.