Spain is the top source of imported fruit and vegetables in Swiss supermarkets. However, higher wages, tighter regulations and competition from outside Europe are eroding its dominance. The A-7 highway, also known as the Mediterranean highway, hugs the eastern part of the Costa del Sol in southern Spain beloved by British and German holidaymakers and retirees. Rental cars and taxis ferrying them to the seaside resorts and second home residential complexes built during the real estate boom of the 2000s must share the highway with trucks transporting fruit and vegetables to the rest of Europe. Halfway between Malaga and Almeria, the beaches and resorts give way to patches of plastic greenhouses squeezed between the arid hills and the sea. Just within reach of Almeria lies the town of El Ejido. Perched like an island among 13,000 hectares of plastic greenhouses, it is the posterchild of Spanish supremacy in tomatoes, cucumbers and peppers. El Ejido is the epicentre of the mar de …