Agricultural protectionism -- the use of tariffs, quotas and other controls in trade policy to limit the imports of foreign agricultural products in favour of the domestic market -- is present and widespread in Switzerland's foreign trade. Historically, this sector has been one of the most restricting in Swiss trade policy: Almost every product also grown domestically is subject to a form of trade control. Of the annual produce imports amounting to roughly two billion Swiss Francs, the most important types are tomatoes, pepperoni, berries and citrus fruits. The most important trade partners are Spain and Italy. Tariffs imposed on goods during the Swiss harvest period (in excess of the admissible import quota) are prohibitively high. This is documented by the fact that out-of-quota imports are very limited -- both in frequency and trade volume. There is evidence that the seasonal trade controls affect Swiss market prices. While trade barriers keep Swiss products competitive during their harvest season, the limited supply of imported products and/or the rapid increase of import values through high duties have price-increasing effects on produce markets in Switzerland.