Alemania: How will Brexit affect the potato industry?
Along with Germany, the UK is the EU’s largest potato consumer, with over six million tons used each year. The UK produces about 5.5 million tons of potatoes each year leaving them with a deficit.

Even after the referendom, the UK will still remain in the EU, at least until the Spring of 2019. It could even be longer while negotiations continue between the UK and EU member states. In the year to April, the UK imported GBP266m (EUR332.5m) more potatoes and potato products than it exported, with sales into the country worth more than half a billion euros.
Potato seeds themselves though do not fall under the 14% tariff agreed by the WTO and could have a tariff of 4.5%. This could mean a minimal impact on the seed trade itself but the fate of the potato industry at large is left unknown.
Fuente: http://www.freshplaza.com/article/167764/How-will-Brexit-affect-the-potato-industry