British and US accused of poppy plague warfare in Afghanistan

Britain and the US have been accused of launching secret biological warfare on Afghanistan's poppy fields in a bid to blight the opium crop. Poppy plants have been suffering from a mysterious disease which leaves them yellow and withered and slashes the yield of opium resin which is sold on and processed into heroin.

The worst affected farmers have said the scale of the infection is unprecedented. Yields have dropped by up to 90 per cent in some fields they complained. Farmers are claiming that the British and Americans are responsible for the outbreak of the poppy plague but officials have strongly denied involvement. Samples of diseased plants are awaiting tests in Kabul and the cause remains unclear.

The blight was first noticed a month ago with reports it was linked to an infestation of aphids in wheat and fruit trees. It has since been found in four provinces across the south. Early surveys suggest half the crop in northern Helmand is affected and a fifth of fields in the province's south. Symptoms have been spotted in Kandahar, Zabul and Uruzgan. The United Nations said the disease would contribute to a significant drop in the opium harvest from last year's total of nearly 7,000 tonnes.

The country grows about 90 per cent of the world's opium. Tithes and protection money from the drug trade are estimated to give up to £60m a year to the Taliban-led insurgency. The allies have spent billions of pounds trying to cut opium cultivation, but have rejected crop spraying, fearing that robbing farmers of their livelihood will push them to the militants. The British-led anti-drugs strategy has instead tried to wean farmers from opium on to wheat, saffron and fruit.