The Irish Farmers Association has written to the State's 1,500 main potato growers warning that they will have to change existing practices when harvesting early potatoes to save the main crop threatened by blight.
The growers have also been warned by potato merchants that, from next week, they will not accept damaged or diseased potatoes, as complaints are mounting.
According to Mr Jim Thornton, the IFA's potato marketing co-ordinator, the difficulties began in June with cold, wet weather and very little sunshine. This was compounded last month by unsettled weather conducive to the spread of blight which is at a 10-year high not only in Ireland but across the rest of Europe.
He said growers of early potatoes usually harvest crops without burning off the stalks. This "green top harvesting" contributed to the rapid spread of the disease to the rest of the crop.
"We have written to the main growers in the country to advise them not to green top harvest but to burn off the stalks before harvesting. We have also advised against delivering crops straight from the fields to the wholesalers."