South Africa has referred the European Union to the World Trade Organisation over Brussels’ threat to refuse entry to South African fruit because of citrus fungal disease black spot, trade minister Rob Davies said on Thursday.

In a statement, Davies called the threat “protectionist”, saying there was no scientific consensus to support the EU’s claim that fruit from South Africa with the fungal disease could infect European orchards.

South Africa is the main source of oranges for the juice drunk by consumers in Britain, Germany and France during Europe’s summer. Southern European growers fear the fungus could take hold in their citrus groves.

Davies said the ban on South Africa’s citrus fruit was “aimed at restricting highly competitive citrus imports to the benefit of citrus producers in the EU”.

The EU did not immediately respond to request for comment.

About 45 percent of South Africa’s 8 billion rand-a-year citrus exports end up in the EU, but the presence of citrus black fruit in some shipments led to a ban of lemons, oranges and tangerines late last year.

In September, the Citrus Growers Association of Southern Africa said it would voluntarily suspend citrus exports to the EU in order to comply with the EU standards against the fungus.

Citrus black spot causes unsightly lesions on the fruit and leaves, reducing both harvest quality and quantity.

The African producers maintain fruits cannot transfer the disease and say banning their produce from all EU countries is unfair because there are no citrus groves in northern Europe due to the colder climate, meaning there was no risk of infection.