A status yellow blight warning has been issued by Met Éireann for the Republic of Ireland.
Weather conditions conducive to the spread of potato blight occurred in Munster, Connacht and south Leinster on Saturday, spreading to the rest of Leinster and Ulster on Sunday and Monday.
On Tuesday and Wednesday, Met Éireann said that weather conditions conducive to the spread of potato blight will occur in Connacht, Donegal, Cavan, Monaghan, Longford and Westmeath, retreating to just affect northwestern coastal counties on Thursday.
There may be some limited opportunities to spray on Monday, it said.
The warning remains in place until 12pm on Thursday.