Abstract
In the EC, for a long time, only copper-and sulphur-based products were allowed to control a variety of diseases on different crops. However, it is well-known that these products also have negative side effects on beneficial organisms and the soil. For many years researchers have been looking for alternatives to reduce their use and /or replace them. Different carbonates have been investigated intensively in the last years. They are present in nature and were used in the past in organic farming. With Decree 404/2008, Annex II of Regulation (EEC) No. 2092/91 was updated and potassium bicarbonate (PBC) was included into the list of active substances allowed in organic farming. On 1 January 2009, potassium bicarbonate was also included into Annex I of Council Directive 91/414/EEC concerning the placing of plant protection products on the market. Field trials carried out from 2003 to 2009 in South Tyrol evidenced an interesting efficacy of carbonate-based products against apple scab and other diseases, but also phytotoxic side effects emerged depending on the formulation and the applied rate. First results were presented in the proceedings of the 12 th and 13 th Ecofruit conference. The results of recent field trials are presented, which aimed at evaluating the efficacy of different carbonate-based products in stopping further apple scab development and thus their curative action.