According to independent potato specialist of Root Crop Consultancy Howard Hinds, Alternaria has become much more of an issue in UK potato crops, with severe infections being experienced in susceptible varieties such as Markies.
"Not all late blight fungicides have activity on Alternaria and products with specific activity on this disease have been developed. But timing is not fully understood and new research into application timing has been undertaken to ensure the most effective control," he says.