Universidade Federal do Rio Grande do Sul

Brazil, especially due to the attraction exerted by their red and aromatic fruits (Vieira 2001; Coll et al. 2006). In Brazil, the area grown with strawberry is estimated in 3,500 ha, located mainly in the states of Minas Gerais (41.4%), Rio Grande do Sul (25.6%), São Paulo (15.4%), Paraná (4.7%), and Federal District (4%) (Calvete et al. 2005). In Rio Grande do Sul (RS), the area grown with strawberries is of 700 ha. The crop is grown mainly in low tunnel and more recently in a semi-hydroponic system (Emater 2004; Embrapa 2007). In the low tunnel system the seedlings are planted in the soil using beds covered with plastic and sustained by galvanized iron arches, forming a tunnel which main function is to protect the plants from rain, frost, UV rays, and to reduce the spread of pests and diseases (Embrapa 2005). The semi-hydroponic sys-tem is derived from the hydroponics system and is conducte