18th-century pesticide survives for another year
A chemical used for fighting plant diseases since the 18th century has been approved for continued use in the EU by organic farmers, despite the E u r o p e a n F oo d Safety Au th o r i t y a n d E u r o p e a n Chemicals Agency identifying some risks to farm workers, b i r d s , m a mm a l s a n d s o i l organisms.
The European Commission a n d m e m b e r s t a t e s h av e extended once again the autho r i s a t i o n fo r c o p p e r c o mp ou nd s , i n clu di n g c op p e r sulphate, as bactericides and fungicides in organic farming, particularly for potato, grape, tomato and apple production. Part of the legend behind the age- old copper sulphate pesticide is that it was first used by those who noticed that fields close to copper-smelting factories were not damaged by potato blight.
The plant protection proper ties of Bordeaux mixture (copper sulphate, water, and lime) were also repor tedly discovered by accident, when French winemakers sprayed it on their vineyards to deter thieves from stealing ripening grapes.
Since 1885, Bordeaux mixture has been used against the potato blight fungus, with the mixture known as “bluestone” well known to Irish farmers, and widely used by them until more modern fungicides became available since the 1940s.
In more recent years, org anic fa rmers here were still using Burgundy mixture (copper sulphate and washing soda dissolved in water), as the only substance permitted for blight control, but they were limited to 6kg per hectare per year, with prior approval from their organic certification body. Organic farmers are only allowed to use pesticides derived from natural sources, and processed lightly, whereas conventional farmers can also use synthetic substances. However, there have been question marks over their use o f c o pp e r s u l ph at e , du e t o fears about copper’s toxicity, and accumulation in the soil and in organic foods.
The European Commission extended approvals in 2014 for use of copper compounds, on condition that measures were taken to reduce their use, and to allow further environmental assessments to be carried out.
This extension was due to expire last week, pending the results of a monitoring programme.
But in December, the EU’s Standing Committee on Plants, Animals, Food and F e e d wh i c h h a s m e m b e r s from the Commission and the member states, extended a p p ro va l s for one year, although the monitoring pro- gramme results have not been published.
Only France and Sweden a re be li eve d t o h av e vo t e d against re-approval.
A s a re s u l t , p e rh a p s t h e only pesticide celebrated in Irish poetry continues in use. Spraying the Potatoes
(by Patrick Kavanagh) The barrels of blue potatospray,
Stood on a headland in July, B e s i d e a n o r c h a r d w al l where roses,
Were young girls hanging from the sky.
Spraying the potatoes with bluestone; the more than 130-years old technology continues after the European Commission and member states extended once again the authorisation for copper compounds.