Uses of copper for crop protection. Approved uses Copper is approved for crop protection uses against a variety of diseases due to fungi, bacteria and oomycetes, mainly on grapes, fruit crops, and vegetable crops (Table 1). - For perennial crops, approved uses of copper include fungal and bacterial diseases affecting grapevines, stone fruits, pome fruits, and tree nuts. Copper treatments are also occasionally used against diseases for which they are not approved, including xxxxx rot blossom blight in apricots and black rot in grapes. - For market garden crops, copper is approved against fungal and bacterial diseases of a dozen or so crops belonging to various botanical families. - For major field crops, approved uses of copper are limited to combating late blight in potatoes, and for a few fungal diseases in wheat and rye that are transmitted by seed. - Finally, copper is approved against various fungal diseases affecting perfume, aromatic, and medicinal plants (PAMCP); ornamental species; and seed crops, and for diseases that develop on tree cuts. The maximum allowed dose for copper-based formulations long stood at 6 kg of metal copper/ha/yr, with a 5 yr moving average (reference). Rates recommended to producers by agricultural advisory services may be considerably lower than this maximum allowance. On December 13th, 2018, the EU decided to reapprove copper but with a lower dose of 4 kg per hectare per year. In addition, over 7 years the amount cannot acceded 28 kg/ha (EC implementation regulation EU-2018/1981 renewing the approval of the active substances copper compounds, as candidates for substitution, in accordance with Regulation EC-No 1107/2009 of the European Parliament and of the Council) This is part of the copper minimisation strategy, and this 33% reduction of copper use makes research into alternatives to Cu or better use of minimised copper even more timely. The above regulation is valid from 1 January 2019 to 31 December 2025 (7 years); after 2025, copper use is likely to be reduced even further (e.g. 3 kg/ha/yr or 2 kg/ha/yr) or banned altogether. Target pathogens Pathogenic microorganisms targeted by the crop protection uses of copper belong to three major groups. Conditions for disease development and the methods available to fight these diseases depend on the biological characteristics of the different pathogen groups. The three groups are: - Fungi, especially Ascomycetes. Ascomycetes are fungi capable of both sexual reproduction (producing perithecia, which overwinter in ...
