Less than 30% of organic potato farmers used copper last year, with the availability of blight resistant varieties

Despite last year being the worst for blight in 50 years, fewer than 30% of Soil Association organic farmers resorted to the use of copper. Two-thirds managed through the use of blight resistant varieties [1], crop rotations [2] and burning or chopping infected vegetation [3] - this is good news, contrary to the Daily Mail's doom and gloom report yesterday ["Thousands of tons of organic food produced using toxic chemicals", 1 January 2008].

In 2006, 58 organic farmers applied to the Soil Association to use 2.2 tonnes of copper. Last year, out of 300 growers, 85 applied for permission as the wet summer created the right conditions for blight to spread.

The Soil Association only allows the use of copper when disease is a major threat to the crop and hopes to reduce the amount farmers can use as alternative organic controls and resistant strains of potatoes are being developed. The amount that organic farmers use is tiny compared to the amount used on non-organic farms where it can be routinely applied as a soil conditioner. Up to four pesticides are permitted but only as a last resort by the Soil Association; this compares to the 311 chemicals that are available to non-organic farmers. The maintenance of biodiversity to encourage natural predators, crop rotations and preserving optimum crop health are fundamental practices used in organic systems to reduce the incidence of pests and disease.