The Use of Copper Pesticides in Germany and the Search for Minimization and Replacement Strategies

<div class="page" title="Page 1"><div class="layoutArea"><div class="column"><p><span style="font-size: 9.000000pt; font-family: 'NimbusSanL';">Copper pesticides used to control fungal and bacterial diseases such as grapes downy mildew </span><span style="font-size: 10.000000pt; font-family: 'NimbusSanL';">(</span><span style="font-size: 10.000000pt; font-family: 'NimbusSanL'; font-style: italic;">Plasmopara viticola</span><span style="font-size: 10.000000pt; font-family: 'NimbusSanL';">), downy mildew of hops (</span><span style="font-size: 10.000000pt; font-family: 'NimbusSanL'; font-style: italic;">Pseudoperonospora humili</span><span style="font-size: 10.000000pt; font-family: 'NimbusSanL';">), apple scab (</span><span style="font-size: 10.000000pt; font-family: 'NimbusSanL'; font-style: italic;">Venturia </span><span style="font-size: 10.000000pt; font-family: 'NimbusSanL';">spp.), fireblight (</span><span style="font-size: 10.000000pt; font-family: 'NimbusSanL'; font-style: italic;">Erwinia amylovora</span><span style="font-size: 10.000000pt; font-family: 'NimbusSanL';">) and potato late blight (</span><span style="font-size: 10.000000pt; font-family: 'NimbusSanL'; font-style: italic;">Phytophthora infestans</span><span style="font-size: 10.000000pt; font-family: 'NimbusSanL';">), play an important role in plant protection. In a 2013 survey of copper application in Germany we found, that while the amounts of copper used per hectare in conventional grape (0.8 kg ha</span><span style="font-size: 7.000000pt; font-family: 'CMSY7'; vertical-align: 4.000000pt;">−</span><span style="font-size: 7.000000pt; font-family: 'CMR7'; vertical-align: 4.000000pt;">1</span><span style="font-size: 10.000000pt; font-family: 'NimbusSanL';">), hop (1.7 kg ha</span><span style="font-size: 7.000000pt; font-family: 'CMSY7'; vertical-align: 4.000000pt;">−</span><span style="font-size: 7.000000pt; font-family: 'CMR7'; vertical-align: 4.000000pt;">1</span><span style="font-size: 10.000000pt; font-family: 'NimbusSanL';">) and potato-farming (0.8 kg ha</span><span style="font-size: 7.000000pt; font-family: 'CMSY7'; vertical-align: 4.000000pt;">−</span><span style="font-size: 7.000000pt; font-family: 'CMR7'; vertical-align: 4.000000pt;">1</span><span style="font-size: 10.000000pt; font-family: 'NimbusSanL';">) were well below those used in organic farming (2.3, 2.6 and 1.4 kg ha</span><span style="font-size: 7.000000pt; font-family: 'CMSY7'; vertical-align: 4.000000pt;">−</span><span style="font-size: 7.000000pt; font-family: 'CMR7'; vertical-align: 4.000000pt;">1</span><span style="font-size: 10.000000pt; font-family: 'NimbusSanL';">, respectively), they were nearly identical to those used in apple growing (1.4 kg ha</span><span style="font-size: 7.000000pt; font-family: 'CMSY7'; vertical-align: 4.000000pt;">−</span><span style="font-size: 7.000000pt; font-family: 'CMR7'; vertical-align: 4.000000pt;">1</span><span style="font-size: 10.000000pt; font-family: 'NimbusSanL';">). Due to the smaller farming area, only 24% (26.5 tonnes) of the total amount of copper was applied in organic farming compared to 76% (84.8 tonnes) in conventional farming. Since 2001, the Federal Agency for Agriculture and Food (BLE) promoted a copper research and minimization strategy which was funded with a total of </span><span style="font-size: 9.000000pt; font-family: 'NimbusSanL';">C</span><span style="font-size: 10.000000pt; font-family: 'NimbusSanL';">10.2 million. Our status quo analysis of research in this field shows that some progress is being made concerning </span><span style="font-size: 9.000000pt; font-family: 'NimbusSanL';">alternative compounds, resistant varieties and decision support systems. However, it also shows that new </span><span style="font-size: 10.000000pt; font-family: 'NimbusSanL';">approaches are not yet able to replace copper pesticides completely, especially in organic farming. In </span><span style="font-size: 9.000000pt; font-family: 'NimbusSanL';">integrated pest management, copper preparations are important for the necessary active substance rotation </span><span style="font-size: 10.000000pt; font-family: 'NimbusSanL';">and successful resistance management. The availability of such products is often essential for organic </span><span style="font-size: 9.000000pt; font-family: 'NimbusSanL';">grapes, hops and fruit production and for extending the organic farming of these crops. We conclude that the complete elimination of copper pesticides is not yet practicable in organic farming as the production of several organic crops would become unprofitable and may lead to organic farmers reverting to conventional production. Several existing copper reduction strategies were, however, identified, and some, like modified forecast models adapted to organic farming, varieties more resistant to fungal diseases and new alternative products, already contribute to copper minimization in German agriculture. </span></p></div></div></div>