Gabriel Martins Ferreira, Rafaele Regina Moreira, Luciane Bertoletti Barros,* Tiago Miguel Jarek, Luiz Antonio Biasi, and Louise Larissa May De Mio
*Universidade Federal do Paraná, UFPR, Rua dos Funcionários 1540, Curitiba, Brazil (lubbio@gmail.com)

Areas devoted to organic viticulture production have increased significantly. Copper-based products are commonly used to control fungal diseases in organic viticulture. However, prolonged use of copper can promote accumulation of this metal in the soil, making it potentially toxic, contrary to the basic principles of organic agriculture. Therefore, alternative products are desirable for organic production. Among previous studies seeking to control these fungal diseases, most show efficiency only in vitro. Two experiments were carried out on experimental vineyards in Southern Brazil to test alternative products for controlling foliar grapevine diseases under field conditions. The selected products, including a commercial product based on chitosan, biostimulant, biological controllers (fungi and bacteria), extracts of plant species, essential oils, and sulfocalcium syrup, were sprayed weekly from October to April in two seasons (2008/09 and 2009/10) and evaluated for incidence and severity of leaf spot (Pseudocercospora vitis) on cultivar Bordo (Vitis labrusca). The area under the disease progress curve (AUDPC) was calculated and used to compare the results using the Scott-Knott test. In the second year, all treatments reduced disease incidence. The isolated bacterial, biostimulant, and chitosan were more promising for disease control, since they also reduced the severity of symptoms.

Funding Support: CAPES/ CNPq